MANUAL OF PHYSICAL DISTANCING Space, Time, and Cities in the Era of Covid-19 Principal Investigators: Paul Lewis, Princeton University Guy Nordenson, Princeton University David J. Lewis, Parsons School of Design Marc Tsurumaki, Columbia University with Oluwatobiloba Ajayi, Shane Algiere, Maeliosa Barstow, Barrington Calvert, Victor Guan, Larissa Guimaraes, David Himelman, Nick Kim, Anna Knoell, Simon Lesina-Debiasi, Tiffany Lim, Yasamin Mayyas, Luis Munoz, Juan Pablo Ponce de Leon, Clara Roth, Jay Schairbaum Release Date Version: August 10, 2020
MANUAL OF PHYSICAL DISTANCING
SECTIONS WITHIN THIS REPORT
Space, Time, and Cities in the Era of Covid-19 About This report provides a visual graphic to the challenges of living in the time of Covid -19 with a particular attention to a range of scales, from classrooms to urban areas where density is an imperative to a creative and vibrant life. The intent of this report is to visualize ongoing studies and practices developed in relationship to addressing the spread and impact of Covid-19. The goal is to provide greater clarity over the spatial implications of addressing and mitigating Covid-19. To the extent possible peer reviewed medical basis for spatial practices are provided, from which the visual material in this document is an illustration.
Covid-19: Gradient of Risks
Case Study: 82nd Street Jackson Heights
Case Study: Classrooms
Urban Systems: Cycling Infrastructure
Buildings: Public Areas
History: Global Pandemics
Objective Physical Distancing is instrumental to slowing the transmission of Coronavirus and the disease it causes, COVID-19. The density of the city, which has historically been considered its greatest asset, economically, socially and environmentally, is now precisely at odds with the realities of a pandemic, and has become a crippling vulnerability. Design strategies addressing collective spaces such as classrooms, public transportation, the streetscape, and parks have the potential to recalibrate the city in order to better negotiate the incompatibility between the functional density of urban spaces and the protection of the health, safety and welfare of the public in the face of communicable disease. Key to this process is the visualization and spatialization of research on the gradient of risks associated with Covid-19.
Funding This work is made possible by Princeton University Funding Program for Rapid, Novel and Actionable COVID-19 Research Projects. Professor Paul Lewis and Professor Guy Nordenson from Princeton School of Architecture are principal investigators. The work on the report has been executed in collaboration with Marc Tsurumaki (Adjunct Associate Professor-Columbia University), David J. Lewis (Professor-Parsons School of Design), and Oluwatobiloba Ajayi, Shane Algiere, Maeliosa Barstow, Barrington Calvert, Victor Guan, Larissa Guimaraes, David Himelman, Nick Kim, Anna Knoell, Simon Lesina-Debiasi, Tiffany Lim, Yasamin Mayyas, Luis Munoz, Juan Pablo Ponce de Leon, Clara Roth, Jay Schairbaum.
Disclaimer
100 people 6’ distancing, min. Additional pedestrian and bicycle lanes
This document provides visual material as complements to existing research. The material within this document does not constitute independent medical or public health advice. Please refer to the cited articles, and other public health institutes and agencies for critical details, and additional information and directives. AUG 10, 2020
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COVID-19 EXPOSURE AND TRANSMISSION INFORMATION
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ANALYSIS OF GRADIENT OF EXPOSURE CDC and WHO recommendations
The variations in recommended physical distance ranges from 3’ to 6’ to 2m. All of these distances provide a reduction in the risk of infection from droplet transmission. Most larger droplets settle within 6’, but 6’ should not be interpreted itself as a line of safety but rather as a part of a gradient of risk reduction. Factors such as time, droplet velocity, wind movement, aerosol transmission and role of masks impact this gradient of risk.
Source: 1. Centers for Disease Control. Social Distancing, Quarantine, and Isolation DOI: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/ social-distancing.html
Droplet diameter 10 to 5 μm
CDC recommends maintaining a physical distance of 6 feet, based on the assumption that COVID 19 spreads from an infected person when they cough, sneeze or talk. The infection is thought mainly to be transmitted in large particles (droplets) that typically remain suspended in the air for a limited period of time and settle within 6 feet from the source.
Droplet transmission
Aerosol transmission
Source: 2. World Health Organization, 2014. Infection prevention and control of epidemic-and pandemic prone acute respiratory infections in health care. WHO guidelines Pandemic-Prone Acute Respiratory Infections in Health Care. DOI: https://www.who.int/csr/bioriskreduction/infection_control/publication/en/
This report, completed in 2014, provides general recommendations for addressing acute respirator infections (ARI). Based on studies of previous ARI outbreaks, the WHO offered a general recommendation to “Maintain spatial separation (distance of at least 1 m) between each ARI patient and other individuals not wearing PPE, to reduce the transmission of ARI pathogens.” However, they note this was a “Strong recommendation, very low to low quality of evidence...”
3’ (1 meter) WHO, France
Duration of the aerosols vaibility Duration of the aerosols vaibility
4.9’ (1.5 meter) Germany, Austrailia 6’ (1.8 meter) CDC, USA 6.5’ (2 meter) UK, Japan, South Africa
WHO CLASSIFICATION OF INFECTIOUS RESPIRATORY DROPLETS WHO CLASSIFICATION OF INFECTIOUS RESPIRATORY DROPLETS WHO classification of infectious respiratory droplets DROPLETS > 5 μm* Droplets>>5 5 μm* DROPLETS μm* AEROSOL μm* Aerosol<≤5 5* AEROSOL < 5 μm* −6
μm:μm*: micrometer (10 (10 ) m-6 ) m micrometer −6 μm:The micrometer (10 hair ) mhair The average human diameter is about 70 micrometers average human diameter is about 70 μm The average human hair diameter is about 70 micrometers
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ANALYSIS OF GRADIENT OF EXPOSURE Respiratory emission and distance
Droplets and aerosols released with velocity through coughs and sneezes can reach distances of 23 to 27 feet.
Source: Bourouiba, Lydia (March 26 2020). Turbulent Gas Clouds and Respiratory Pathogen Emissions. DOI: https://jamanetwork.com/journals/jama/fullarticle/2763852
This report examines the dispersal of droplets from exhalation, coughs and sneezes, and reveals that they are composed of two types of droplets: loose droplets which evaporate quickly, and what they call a turbulent gas cloud which carries the droplets further and helps them persist longer. Peak exhalation speeds can reach up to 33 to 100 feet per second (10-30 m/s), creating a cloud that can span approximately 23 to 27 feet (7-8 m). The report includes video simulations.
Droplet diameter 10 to 5 μm
Droplet transmission
Aerosol transmission
Figure: Close up view of emission within 50 cm (20 in) from a healthy person during a violent exhalation (sneeze).
Figure: Intermediate view of emission within 110 cm (43 in) from a healthy person during a violent exhalation (sneeze). 3’ WHO 6’ CDC 23’-27’ MIT
Figure: Multiphase turbulent gas cloud from a human sneeze
-6
μm*: micrometer (10 ) m The average human hair diameter is about 70 μm
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ANALYSIS OF GRADIENT OF EXPOSURE Aerodynamics and social distancing Source: B. Blocken, F. Malizia , T. van Druenen, T. Marchal. (April 13 2020). Towards aerodynamically equivalent COVID19 1.5 m social distancing for walking and running.
This study identified the impact of time and velocity on the distribution of particles, showing that particles from running would reach a distance of 33’ behind a runner, and cycling would reach a distance of 66’ behind a bicyclist. But, the dilution of these particles by outside air movement over these distances makes the infection risk lower.
STANDING Standing
Cycling Cycling 6’ 5’ 4’ 3’ side 2’ 1’ by side
66’
6’ 5’ 4’ 3’ 2’ 1’
66’
6’ 5’ 4’ 3’ 2’ 1’
66’
http://www.urbanphysics.net/COVID19_Aero_Paper.pdf
This study is based on fluid dynamic modeling to examine how movement of air might impact someone when walking, running and cycling and to determine potential impact on safe social distancing. The study analyzes four configurations between the leading and trailing person. Those configurations are: side by side, in line and staggered. The study didn’t consider the effect of external wind movement on those activities. The study results indicate that more social distance may be required for faster pace activities, in particular when the trail person is in the slipstream of the leading person. It also indicates that the highest exposure may be when the trailing person is in line behind the leading person and when the distance is decreased between the two.
6’ 5’ 4’ 3’ 2’ 1’
Walking 2.5 miles / hr (4 km/hr)
6’ 5’ 4’ 3’ 2’ 1’
Cycling Inline The study recommends to switch lane at 66’ prior to reaching the lead cyclist
15’
6’ 5’ 4’ 3’ 2’ 1’
Running 8.9 miles / hr (14.4 km/hr)
33’
15’
6’ 5’ 4’ 3’ 2’ 1’ 6’ 5’ 4’ 3’ 2’ 1’
6’ 5’ 4’ 3’ 2’ 1’
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6’ 5’ 4’ 3’ 2’ 1’
66’
Cycling in staggered formation
6’ 5’ 4’ 3’ 2’ 1’
6’ 5’ 4’ 3’ 2’ 1’ 6’ 5’ 4’ 3’ 2’ 1’
6’ 5’ 4’ 3’ 2’ 1’ 6’ 5’ 4’ 3’ 2’ 1’
6’ 5’ 4’ 3’ 2’ 1’
66’
6’ 5’ 4’ 3’ 2’ 1’
66’
6’ 5’ 4’ 3’ 2’ 1’
66’
33’ 15’
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ANALYSIS OF GRADIENT OF EXPOSURE Persistence in air and virus effectiveness
Aerosol particles can remain viable suspended in the air for up to 3 hours.
Source: 1. Van Doremalen , Bushmaker, Morris, Holbrook, Gamble, Williamson, Tamin, Harcourt, Thornburg, Gerber, Lloyd-Smith. (April 16 2020). Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. New England Journal of Medicine Link: https://www.nejm.org/doi/full/10.1056/NEJMc2004973
Viability of virus in aerosols, SARS-CoV2 remains viable up to 3 hours
( Conditions at 69.8 -73.4°F (21 to 23°C) and 40% relative humidity over 7 days)
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27’
23’
Aerosol transmission
6’
3’
Source
Droplet transmission
20’
The study examined two strains of viruses (SARS-CoV-2 and SARS-CoV-1) on various surfaces. SARS-Cov-2 or remained viable in aerosols throughout the duration of the experiment (3 hours). The laboratory test experiment also focused on the stability on different materials. The results indicate that aerosol and fomite transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days.
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ANALYSIS OF GRADIENT OF EXPOSURE Persistence in air and virus stability on surfaces
Virus particles can live for up to 7 days on certain hard and non-porous materials, but are much less viable on soft, porous surfaces. From a maintenance perspective, porous surfaces are harder to clean than hard, non-porous surfaces.
Stability of SARS-CoV in relation to temperature
100°C ( 212 °F)
Boiling point of water
Virus inactive after 5 mins incubation period 70°C ( 158 °F)
22°C ( 71.6°F)
Room temperature
Virus highly stable at 4°C (39.2 °F)
Range of temperatures in the study
4°C ( 39.2°F)
Freezing point of water
The report explored the stability of SARS-CoV-2 in various environmental conditions, by measuring the stability of the virus in relation to different temperatures, surfaces, and disinfectants. The stability of the virus at various temperatures was measured based on a 14 day incubation period. According to the study the virus is highly stable at 4°C (39.2 °F). However, it’s sensitive to heat. The time for the virus inactivation was reduced to 5 minutes when the incubation temperature increased to 70 °C (158 °F). The virus was more stable on smooth surfaces. The study found that the virus becomes inactive after 3- hour incubation on printing and tissue papers, and 2 days for treated wood and cloth. While on smooth surfaces as glass and banknotes the virus lasted through 4 days and on stainless steel and plastic through 7 days.
Not in scope of study
0°C ( 32°F)
Source: Alex W H ChinaJulie T S ChuaMahen R APereraaKenrie P Y Huia Hui-LingYena Michael C W Chana Malik Peirisa Leo L M Poona (April 2 2020). Stability of SARSCoV-2 in different environmental conditions DOI:https://doi.org/10.1016/S2666-5247(20)30003-3
STABILITY OF SARS-CoV IN RELATION TO SURFACE SARS-CoV-2 was more stable on smooth surfaces according to the study ( Conditions at room temperature with relative humidity around 65% ) Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Surface Printing & tissue Treated wood & cloth
Up to 3 hours less than a day
Up to 2 days
Smooth surface glass and banknote
Up to 4 days Up to 7 days
Stainless steel and plastic
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ANALYSIS OF GRADIENT OF EXPOSURE Air and fomite contaminants in relation to ambient environment Masks
Cough and sneeze can cause large droplets to travel further by creating a turbulent gas cloud. Wearing a mask should mitigate the emission produced through sudden sneeze or cough, but masks increase hand to face contact and may provide a false sense of protection
Surfaces Droplets may settle on surfaces, which acts as a source for fomite infection for instance droplets falling on tables and door knobs. Depending on the material of the surface the virus could be viable for up to 7 days
Viral load Virus stability in aerosols could last up to 3 hours, possibly longer in enclosed spaces depending on viral load build up from the quantity of occupants and the amount of air exchanges, fresh air, humidity and other environmental factors. HVAC Mechanical systems will also affect viral load aerosols that may float into mechanical ventilation system. In addition the viral load is affected by HVAC filter type, rate of air changes per hour (ACH), room temperature and relative humidity. The risk of infection from viral load will be decreased with fewer occupants and the duration that those occupants are there; increasing amount of fresh air will dilute the viral load and decrease the risks. Relative humidity between 40 and 60% is ideal. Too low increases the viruses impact inside the lungs, while too high a humidity increases the viability of the virus.
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ANALYSIS OF GRADIENT OF EXPOSURE Viral build up in relation to ambient environment Ventilation
Air cleaning and disinfection
Viral load
Surface fomites
For indoor setting it is imperative to understand the role of viral build up which is related to the duration of exposure, occupant load per volume of air in space, the scale of the space, and the flow of air.
UV disinfectant appliances
Portable air cleaner
Factors of viral build up Duration
Occupant load per cubic volume of air in space
Z
Scale of Space - volume Z
Z
Z
X X X
X
X X X
Y Z Z Z Y Y
Y
Y Y Y
Air flow patterns and air change rate, ventilation
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ANALYSIS OF GRADIENT OF EXPOSURE Airborne lifetime during speech Source 1: Stadnytskyi Valentyn, Bax Christina E, Bax Adriaan, Anfinrud Philip (May 13, 2020). The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. PNAS
Speech and other more active exhalation activities increases the amount and duration of oral fluid droplets and aerosols. Droplets remained for up to 14 minutes. 0
2
4
6
8
10
12
14
TIME
0
2
4
6
8
10
12
14
TIME
0
2
4
6 0 8 2 10 4 12 6 14 8
flow of velocity of exhaled air varies with phonation flow of velocity of exhaled air varies with phonation
https://doi.org/10.1073/pnas.2006874117
This study investigated the role of droplets generated during speech in enclosed environment, by utilizing sensitive laser light in order to asses visually the emission and the airborne lifetime. The study observations reveal that loud speech can generate thousands of oral fluid droplets per second. Those result also indicate that transmission could happen even through normal speaking in confined environment with stagnant air. The study considers the potential importance to the spread of SARS-CoV-2 based on the general findings.
10
12
14 TIME
flow of velocity of exhaled flow air of velocity varies of exhaled air varies with phonation with phonation
TIME
The distance at which droplets travel laterally from the speakers mouth during their downward trajectory is dominated by: 1- Total volume 2- Flow of velocity of exhaled air
According to this study loud speech can generate thousands of oral fluid droplets per second. In a confined environment they disappear in a time constant in the range of 8-14 minutes corresponding to droplet nuclei of ca. 4 μm diameter, or 12- to 21-μm droplets prior to dehydration 50 μm
37%
50 μm
50 μm 10
37%
50 μm
10 μm
10 μm
37% 0.37% 0.37%
10 μm
0.37%
The probability that a 50 μm-diameter droplet, prior to dehydration contains at least one virion is approximately 37%
37% The probability that a 10 μm-diameter droplet, prior to dehydration contains at least one virion is approximately 0.37%
0.37%
6
For Covid 19, with an oral fluid average virus RNA load of 7x 10 copies per milliliter ( maximum of 2.35 x 10 9 copies per milliliter)
0
2
4
6
8
10
12
14
0
2
4
6
8
10
12
14
0
2
4
6 0 8 2 10 4 12 6 14 8
TIME (minutes) TIME (minutes)
10
12
TIME 14 (minutes)
TIME (minutes)
The study estimates that 1 minute of loud speaking generates 1,000 virus containing droplet nuclei (aerosol) that remain airborne for more than 8 min
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ANALYSIS OF GRADIENT OF EXPOSURE Aerosol emission during speech Source 1: Asadi Sima, Wexler Anthony S, Cappa Christopher D, Barreda Santiago, Bouvier Nicole M, Ristenpart William D (February 20, 2019). Aerosol emission and superemission during human speech increase with voice loudness. Nature https://www.nature.com/articles/s41598-019-38808-z
Comparison of emission rate/ concentration (particles/s) Left and right of red box indicate 25th and 75th percentiles respectively Red line Indicates Medians
0
2
0
0.1
4
6
8
10
12
16
14
18
Nose
Normal nasal breathing
Mouth
Indicates outliers ( defined as values that exceed 2.7 standard deviations
20
Breathing
Breathing mode
Normal mouth breathing
Deep- Fast
Slow nasal inhalation followed by fast mouth exhalation
Fast- Deep
Fast nasal inhalation followed by deep mouth exhalation
Quiet Loudness level
Speech
This study evaluates on the role of speech in aerosol transmission in order to extend the realm of the research beyond merely exploring the role of sudden respiratory events such as coughing and sneezing. The study data indicates that the rate of particle emission during normal speech increases in relation to the loudness of the voice and the magnitude of voice vibration. Language was not a determining factor in the rate of particle emission. Also the study explored the role of a small portion of individuals who act as “speech superemitters” as stated in this study. The data demonstrated that this superemitter phenomena cannot be fully attributed to phonic structure or magnitude of speech, rather the study suggests that it correlates to other physiological factors.
Speech can yield more particles than regular breathing.
Intermediate
Loud 0.2
0.3
0.4
0.5
0.7
0.6
0.8
0.9
1.0
1.1
1.2
3
(Particles/cm )
Corresponding geometric mean diameter of particles emitted during various modes of breathing versus speech at different loudness levels Mean diameter of particles emitted (µm) 0.5
0.75
1
1.25
1.5
Nose
Normal nasal breathing
Normal mouth breathing
Deep- Fast
Breathing
Mouth
Breathing mode
Slow nasal inhalation followed by fast mouth exhalation
Fast- Deep
Fast nasal inhalation followed by deep mouth exhalation
Quiet
Intermediate
Speech
Loudness level
Loud
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ANALYSIS OF GRADIENT OF EXPOSURE Aerosols in poorly ventilated spaces and SARS-CoV-2 transmission Source 1: G Aernout Somsen, Cees Van Rijn, Stefan Kooij, Reinout A Bem, Daniel Bonn (May 27, 2020). Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. The Lancet.
Figure: Figure:AA 0.00 0.00
Number Numberdensity density 0.05 0.05
0.10 0.10
0.15 0.15
Figure: Figure:AALegend Legend
00 10 10
https://doi.org/10.1016/S2213-2600(20)30245-9
Cough Cough According Accordingtotothis thisstudy studylarge large droplets dropletshas hasbeen beenrelated relatedtoto coughs coughsalong alongwith withsmall smalldroplets droplets Speech Speech
This Thisstudy studyfound foundtwo twodistinct distincttypes typesofofdrops, drops,large largedroplets droplets(100-1000 (100-1000μm μminindiameter) diameter)and andsmall smalldroplets droplets (1-10 (1-10μm), μm),with withsmall smalldroplets dropletsbeing beingmore moreprevalent. prevalent. 100-1000 100-1000μm μm
Droplet Droplet diameter diameter (( μm) μm)
11 10 10
According Accordingtotothis thisstudy studyonly only small smalldroplets dropletswere werefound found during duringspeech speech
22 10 10
This Thisstudy studyfound foundtha thathe thespeed speed ofofthe thedrops dropsranged ranged2-7 2-7m/s m/satat the thestart startofofthe thecough. cough. 1-10 1-10μm μm
33 10 10
Figure: Figure:BB
Note: Note:This Thisstudy studywas wasperformed performedwith withaahealthy healthyparticipant. participant.
00 00 10 10
This Thisstudy studyfound foundthat thatlarge largedrops drops(typically (typically500 500μm μm inindiameter) diameter)fall falldown downdue duetotogravity gravitywithin within11second, second, when whenproduced producedatataaheight heightofof160 160cm cm(eg, (eg,average average speaking speakingororcoughing coughingheight). height).
This Thisstudy studyfound foundthat thatsmall smalldroplets dropletsofoftypical typical radius radiusofof55μm μmwill willtake take99minutes minutestotoreach reachthe the ground, ground,when whenproduced producedatataaheight heightofof160 160cm cm (eg, (eg,average averagespeaking speakingororcoughing coughingheight). height).
Time Time(min) (min) 55
10 10
15 15
20 20
25 25
t t1/2 0.5min min 1/2≈≈0.5 t t1/2 1.4min min 1/2≈≈1.4
11 10 10
t t1/2 ≈≈5.3 5.3min min 1/2 Counts Counts
This study analyzed the emission of droplets instigated by coughs and speech, by measuring the droplet size distribution, travel distance, velocity and trajectory, and airborne time in relation to the level of air ventilation. The first indicator was measured utilizing laser diffraction measurement during speech of a healthy volunteer. In order to determine the speed of the droplets and their trajectory this study utilized spray can laser sheets to track droplets by filming the scattering of laser light. Then, the same laser sheet was used to determine the time of airborne lingering from cough. This process was repeated in three different rooms with three distinct levels of ventilation: No ventilation, poor ventilation and good ventilation. Two types of droplets large (100-1000 μm) and more prevailing small droplets (1-10 μm). Small droplets produced during speech, whereas during cough both large and small droplets were present. This study found in the good ventilation room after 30 s the number of droplets were halved. While the room with no ventilation took about 5 mins. The study indicated that in a poorly ventilated room, the number of droplets was halved in 1.4 min.
Good Ventilation of indoor spaces reduces the airborne droplets and aerosols lingering time in the air. As shown in this study improving ventilation improves the dilution of drops in the air and reduces the concentration of virus droplets.
Average Averagespeaking speakingororcoughing coughingheight height @@5’3” 5’3”(160 (160cm) cm)
22 10 10
Figure: Figure:BBLegend Legend No Noventilation. ventilation. Poor Poorventilation; ventilation;Mechanical Mechanical ventilation ventilationonly. only. 33 10 10
11sec sec
11min min 22min min 33min min 44min min 55min min 66min min 77min min 88min min 99min min 10 10min min11 11min min12 12min13 min13min14 min14min min15 15min min Time Time
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Good Goodventilation; ventilation;Mechanical Mechanical ventilation ventilationsupported supportedby bythe the opening openingofofan anentrance entrancedoor door and andaasmall smallwindow. window.
P. 13
ANALYSIS OF GRADIENT OF EXPOSURE Physical activity and exposure Source 1: Jang S, Han SH, Rhee J-Y (May 15, 2020). Cluster of Coronavirus Disease Associated with Fitness Dance Classes, South Korea . Emerg Infect Dis.
Confined indoor environment with high physical activity such as fitness classes can yield in increasing the risk of exposure and infection.
Fitness dance instructor
Attack rate by instructor and sports facility during an outbreak of COV-SARS 2 associated with fitness dance classes, South Korea,2020.
Potentially exposed, no. Confirmed, no.
https://doi.org/10.3201/eid2608.200633 0
This study evaluated the role of intense physical activity in crowded sports venues in increasing the risk of exposure. This study traced back the infection of individuals that contracted COVID 19, and their infection was  associated with fitness dance classes at 12 sports facilities in Cheonan, South Korea, where instructors had Covid-19 and transmitted it to participants. The study indicated that the duration of classes lasted for 50 minutes twice a week, and there was no interaction between students and instructors beyond the confinement of the class. According to this study 50.9% cases occurred due to transmission between instructors to participants, while 38 cases or 33.9% were in household transmission of instructors and participants, and 17 cases 15.2% were from transmission due to gathering with coworkers and acquaintances. This study indicated that the attributes that might have contributed to the transmission from the instructors to the participants include large class sizes, small spaces and intensity of workouts, plus the humid warm indoor environment in sports facility with turbulent air flow that is generated due to the intensity of the physical activity.Â
Instructor A
Instructor B
Instructor C
Sports facility 1
Attack rate: 70%
Sports facility 2
Attack rate: 30.4%
Sports facility 3
Attack rate: 20%
Sports facility 4
Attack rate: 10%
Sports facility 5
Attack rate: 14.3%
Sports facility 6
Attack rate: 5%
Sports facility 7
Attack rate: 44.4%
Sports facility 8
Attack rate: 22.7%
Sports facility 9*
Attack rate: 60%
Sports facility 10
Attack rate: 66.7%
Sports facility 9
Attack rate: 0%
Instructor D
Attack rate: 20%
Instructor E
Attack rate: 0%
Instructor F
Attack rate: 57.1%
Total
Attack rate: 26.3%
10
20
30
40
50
60
70
210
220
20
14
23
7 5
1
10
1 7
1
20
1 9
4
22
5 5
3
12
18
25
0
20
4
26
0
4
7
57
217
*Instructor C taught pilates and yoga in the same facility as instructor B. Instructor C tested positive for COVID 19, however her students did not get infected which may be due to the lower lower intensity of the fitness classes compared to the instructors teaching fitness dance classes.
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ANALYSIS OF GRADIENT OF EXPOSURE Location of covid particles Virus concentration
Indoor: Negative pressure
Copies μL in recovered buffer 2.0
1.5
1.0
Bedside Table or Bed Rail
https://doi.org/10.1101/2020.03.23.20039446
75.0% positive
Mean concentration 0.263 copies/μL
Air handling Grate Not provided 80.4 %
ROOM SURFACE SAMPLES 80.4 % POSITIVE
Mean concentration 0.819 copies/μL
Floor under bed Not provided Mean concentration 0.447 copies/μL
Room window ledge 81.8% positive Mean concentration 0.219 copies/μL
Misc Personal items 81.3% positive
Included exercise equipment, medical equipment, personal computers, ipads and reading glasses. Mean concentration 0.217 copies/μL
Cellular phones 76.5 %
PERSONAL ITEMS 76.5 % POSITIVE
83.3% positive Mean concentration 0.172 copies/μL
Remote Controls 64.7% positive Mean concentration 0.230 copies/μL
81.0 %
TOILET IN PATIENT ROOM 81.0 % POSITIVE
63.2 %
IN ROOM AIR SAMPLES 63.2 % POSITIVE
66.7 %
HALLWAY AIR SAMPLES 66.7 % POSITIVE
Toilet in patient room 81.0% positive
Range ofgene copis recovered per sample type
This study indicated that virus transmission may occur through both direct (droplet transmission from person to person) and indirect contact (contaminated objects and airborne transmission). The report is based on studying three types of samples for 13 SARS-CoV-2 positive patients. In order to understand the virus transmission, the study indicates that SARS-CoV-2 infection may occur through both direct and indirect contact. The surface samples fell into three main categories: common room surface, personal items and toilets. 77.3 % of the samples were positive. The study found that 76.5% of all personal items sampled were positive, samples from toilets were 81% positive. 81.8% of the window ledges in each room were positive. In room air samples were 63.2% positive. Samples taken in the hallway were 66.7% positive. The study results suggests that aerosol particles produced by the individuals that have COVID-19 can be present even in the absence of cough.
0.5
0.0
Source: Santarpia JL, Rivera, Herrrera, Morwitzer, Creager, Santapria GW, Crown, Brett-Major, Schnaubelt, Broadhurst, Lawler, Reid, Lowe (March 26, 2020 ). Transmission Potential of SARS-CoV-2 in Viral Shedding Observed at the University of Nebraska Medical Center.
An analysis of surfaces in a medical center at the University of Nebraska treating Covid patients revealed that viral particle were found 77.3% of the sites and surfaces that were tested. This study did not establish if the viral load in the aerosols could cause infection.
Mean concentration 0.252 copies/μL
Bedroom air samples 63.2% positive Mean concentration 2.86 copies/ L of air
Hallway air samples 66.7% positive
Mean concentration 2.59 copies/ L of air
Personal Air sampler
SAMPLE TYPES: 1- Surface sample 2- High volume air sample 3- Low volume personal air AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
The study didn’t establish if the viral load in the aerosols is effective to cause infection (copies /L *) Viral load measurement it’s a numerical quantity of virus in a specific volume of fluid
P. 15
ANALYSIS OF GRADIENT OF EXPOSURE Location of Covid particles Liu, Y., Ning, Z., Chen, Y. et al. Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals. Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals . Nature (2020). https://doi.org/10.1038/s41586-020-2271-3
An analysis of surfaces in two Wuhan hospitals treating Covid patients revealed different viral particle concentrations in different rooms and areas. Intensive care units, PPE removal areas, and patients toilet rooms showed higher levels of concentration. Virus concentration
Indoor
Indoor/ Natural ventilation
Indoor/ Small air purifier
Area Size Sq.ft.
Outdoor
Enclosed room; no ventilation
Indoor/ Mechanical Ventilation
Inpatients number/ symptom
This study investigated the aerodynamic mode of transmission through airborne aerosols for SARS-CoV-2, by measuring viral RNA in aerosols in various areas in two Wuhan hospitals and public spaces in Wuhan during the outbreak in February and March 2020. The concentration of the virus in aerosols in isolation wards and ventilated patient rooms was very low. However, it was high in patients’ toilet areas and PPE removal areas. The study found that the level of airborne SARS-CoV-2 RNA in majority of public areas was undetectable except in two areas that are prone to crowding, which might be due to the presence of infected host in the crowd. The study also showed that extensive sanitization of some of the medical areas reduced the levels of viral RNA to undetectable levels.
Indoor; negative pressure
( copies m -3*) Viral load measurement is a numerical quantity of virus in a specific volume of fluid -3
0
3 Site 1. Zone0A Workstation
Site 1. Zone A Workstation A > 200 MILD B < 100 MILD
HOSPITAL 1: FANGCANG
> 5382 ft²
A > 200 MILD NOT PROVIDED
A > 200 MILD B < 100 MILD
12
9
15
12
VIRUS CONCENTRATION (copies m ) 15 18 21 24 27
18
21
24
27
30
30
33
33
36
36
108
108
111
111
114
114
9 ( copies-3)
9 ( copies-3) 1( copies-3) Not provided
A > 200 MILD NOT PROVIDED > 5382 ft² -3) 1( copies
Not provided
A > 200 MILD B < 100 MILD > 5382 ft²
0 ( copies m-3)
0 ( copies m-3)
5 ( copies m-3)
5 ( copies m-3)
Site 16. Meeting room
18 ( copies m-3)
Site 16. Meeting room 2153 ft²
1( copies m-3) > 5382 ft²
Site 3. Zone C Workstation
Site 3. Zone C Workstation > 5382 ft²
9
6
1( copies m-3)
A > 200 MILD B < 100 MILD
Site 2. Zone B Workstation
Site 2. Zone B Workstation > 5382 ft²
6
3
2153 ft²
18 ( copies m-3)
Site 4. Patient Mobile toilet room
Site 4. Patient Mobile toilet room
19 ( copies m-3 )
~11 ft²
19 ( copies m-3 )
~11 ft²
Site 5. Intensive care unit -3 0 ( copies m )
1/ SEVERE
Site 5. Intensive care unit 1/ SEVERE
-3 Site 6. Intensive caremunit 0 ( copies )
Site 6. Intensive care unit 1/ SEVERE
31 ( copies m-3 )
1/ SEVERE
172 ft²
HOSPITAL 2: RENMIN
172 ft²
172 ft²
31 ( copies m-3 )
Site 7. Intensive care unit 1/ SEVERE
172 ft²
172 ft²
Site 7. Intensive care unit 1/ SEVERE
-3 113 ( copies m )
Site 8. Coronary care unit
-3 113 ( copies m ) 0 ( copies m -3)
1/ SEVERE
172 ft²
172 ft²
Site 8. Coronary care unit 1/ SEVERE
Site 18. Passageway for medical staff 0 ( copies m -3)
172 ft²
Site 18. Passageway for medical Site 22. Renmin hospital staff Outpatient Hall 108 ft²
Site 22. Renmin hospital Outpatient Hall
6 ( copies m-3)
108 ft²
-3 6 ( copies m-3)m ) 0 ( copies
8611 ft²
-3 0 ( copies m )
8611 ft²
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 16
ANALYSIS OF GRADIENT OF EXPOSURE Distribution of particles in a room
The analysis of patient rooms for treating Covid-19 identified surfaces that have the greatest contamination rates, with the floor and air exhaust vent having the highest percentage of positive for contamination. Percentage of contaminated swabs from surface samples in rooms with anytests contamination Percentage of contaminated swabs from surface samples in rooms with any contamination
Chia, P.Y., Coleman, K.K., Tan, Y.K. et al ( 29 May, 2020). Detection of air
and surface contamination by SARS-CoV-2 in hospital rooms of infected patients. Nature.
0
10
20
30
40
50
60
70
210
220
https://doi.org/10.1038/s41467-020-16670-2
Locations
Floor
17 sites
Bed rail
17 sites
Locker handle
17 sites
Cardiac table
17 sites
Electric switch
17 sites
Chair
17 sites
Toilet seat & flush 17 sites Air exhaust vent
5 sites
Figure 1: Single general ward airborne infection isolation room layout showing environmental sites sampled (top) and configuration of air samplers (bottom).
N
S S S
5
a
4 2 N
1
b
a
Patient Room a
Bathroom
a b N S
Blue circles mark high 5 touch areas: 1- Cardiac table 2- Bed rail ( Including call bell) 3- Locker 4- Switches 5- Chair Floor Bathroom NIOSH air samplers Position of SKC air samples (only in room1)
S
Anteroom
Figure 2: Single intensive care unit room layout showing environmental sites sampled
1
5 4 2
Anteroom
This study investigated surface and air samples fron hospital rooms of thirty COVID 19 patients not undergoing aerosol-generating procedures in a hospital in Singapore. In order to evaluate the characteristics of envirnmental transmission and the particle size distribution in the air. The environmental surface sampling were collected in three airborne infection isolation rooms ( AIIRs) in the ICU, and 27 AIIRs in the general ward. 254 surface samples were collected. 56.7% of rooms have at least one environmental surface contaminated. Air sampling was performed in three of the 27 AIIRs in the general ward and detects the general ward, and detects SARS-CoV-2 PCR-positive particles of sizes >4 μm and 1–4 μm in two rooms, despite these rooms having 12 air changes per hour. This warrants further study of the airborne transmission potential of SARS-CoV-2. Floor contamination was the most common followed by bed.
Blue circles mark high 5 touch areas: 1- Cardiac table 2- Bed rail ( Including call bell) 3- Locker 4- Ventilator 5- Surgical pendants
Patient Room 3
The rooms had 2 ACH (air exchange per hour), an average temperature of 73.4 F (23 C), relative humidity of 53-59% and exhaust flow of 579.6 m3/h. In three patient rooms, three NOISH samplers were attached to each of two tripod stands and situated at different heights from the ground (1.2m, 0.9m, and 0.7m) near the air exhaust to capture particles from the unidirectional airflow in the room.
Air Sampler
3'-11" 2'-11" 2'-3"
Air exhaust
AUG 10, 2020
Air exhaust
MANUAL OF PHYSICAL DISTANCING
P. 17
ANALYSIS OF GRADIENT OF EXPOSURE Substantially greater risk in indoor spaces
Indoor spaces contribute in the transmitting of COVID-19 from infected individuals to others with a 18.7x more likely transmission rate attributed to closed environments than open air spaces.
Nishiura Hiroshi, Oshitani Hitoshi, Kobayashi Tetsuro, Saito Tomoya, Sunagawa Tomimasa, Matsui Tamano, Wakita Takaji, MHLW COVID-19 Response Team, Suzuki Motoi ( April 16, 2020). Closed environments facilitate secondary transmission of coronavirus disease 2019 (COVID-19) . MedRxiv. https://doi.org/10.1101/2020.02.28.20029272
0
Primary cases in closed environment
0
Other primary cases
1
10
20
30
40
50
60
70
80
2
Total of 110 cases were examined, 27 ( 24.6%) were primary cases who tranmitted covid 19 to others
The mean and variance were 0.6 cases and 2.5 cases as shown in the figure
â&#x20AC;&#x153; The odds that a primary case transmitted COVID 19 in a closed environment was 18.7 times greater compared to open air environment (95% confidence interval*)â&#x20AC;?
confidence interval* : A type of estimated computation extracted from observed data
3
Number of secondary cases per single primary case
The study used contact tracing to determine that closed environments were 18.7 times more likely to be the location for the transmission of Covid-19 than an openair environment. The study used contract tracing to examine 110 cases of which 27 were primary cases in Japan. The report concludes that it is plausible that closed environments contribute to secondary transmission of Covid-19 and promote super spreading events.
Frequency
4
5
6
7
8
9
10
11
12
13
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
14
P. 18
ANALYSIS OF GRADIENT OF EXPOSURE Indoor vs Outdoor Risk
This study of cluster outbreaks in China of more than 3 people underscores the role of indoor spaces rather than outdoor environments in transmission of the virus
Hua Qian, Te Miao, Li LIU, Xiaohong Zheng, Danting Luo, Yuguo Li. ( April 07, 2020). Indoor transmission of SARS-CoV-2 doi: https://doi.org/10.1101/2020.04.04.20053058
Home
Indoor 18°C-24°C IndoorRH* 30%-60% Home Home
Office
conditions
5.8 (or 0.7 ACH for ≤ 10 m2) Median 0.34 ACH (Hou et al., 2019) 18°C-24°C
30%-60% RH* 18°C-24°C 30%-60% RH*
Supermarket
Kiosk
Supermarket Supermarket Kiosk Kiosk
(L/s.person) Ventilation rate (measured CO2 (L/s.person) level ppmCO2 range) (measured
(no/m2°) density (no/m2°)
3.9 (GB) 7.8 (ASHRAE)
7.8 (ASHRAE)
250
intimate 0.32 m
intimate 0.32 m
0.67 m 0.67 m 0.67 m
200
ASHRAE62.1-2004 Zhang et al. (2019) ASHRAE62.1-2004
0.05 0.05
0.30-0.60 3.9 (GB)(GB) 0.15 (ASHRAE) 7.8(GB) (ASHRAE) 3.9
GB50736-2012 GB50016-2014 GB50736-2012 0.30-0.60 social 1.35 m GB50016-2014 GB50736-2012 ASHRAE62.1-2004 social 1.35 m (GB) 0.15 0.30-0.60 ASHRAE62.1-2004 GB50016-2014 social 1.35 Sorokowska m et al.(2017) (GB)(ASHRAE) 0.15
Zhang et al. (2019) ASHRAE62.1-2004 Zhang et al. (2019)
ASHRAE62.1-2004 Sorokowska et al.(2017) Sorokowska et al.(2017)
(ASHRAE)
3.9 (GB)0.08 3.9 (ASHRAE) 7.6(GB) (ASHRAE) 7.6 (ASHRAE)
social 1.35 m 0.08 GB50736-2012 social 1.35 m GB50736-2012 0.08(ASHRAE) social 1.35 m GB50736-2012 ASHRAE62.1-2004 ASHRAE62.1-2004 (ASHRAE) ASHRAE62.1-2004
7.8 (ASHRAE) 0.15 7.8 (ASHRAE)
0.15 ASHRAE62.1-2004 social 1.35 m ASHRAE62.1-2004 0.15(ASHRAE) social 1.35 m social 1.35 m ASHRAE62.1-2004 (ASHRAE)
(ASHRAE)
250 250
Sorokowska et al. GB50736-2012 (2017)et al. Sorokowska (2017)
8.5 8.5
7.8 (ASHRAE)
3.9 (GB) 7.6 (ASHRAE)
(international behavior personal distance) GB50736-2012 (international
intimate 0.32 personal m Sorokowska et al. distance) (2017) GB50736-2012
0.05
8.5
Shopping center Shopping center
Close contact References behavior Occupant (international Close contact References density behavior personal distance) Occupant Close contact References
level ppm range) 5.8 (or 0.7 ACH for ≤ 10 Median 5.8 (or m2) 0.7 ACH for ACH (Hou et ≤ 0.34 10 m2) Median al.,ACH 2019) 0.34 (Hou et al., 2019)
Office Office
Shopping center
Occupant density (no/m2°) Ventilation rate
200 200
Number of outbreaks
Indoor
Ventilation rate (L/s.person) (measured CO2 Thermal conditions level ppm range) Thermal
Number of outbreaks
Thermal conditions
Number of outbreaks
This study examined data from 320 prefectural cities in China between January 4 to February 11, 2020 to determine the location of outbreaks of more than 3 cases per incident. From 318 outbreaks involving 1245 confirmed individual cases, only 1 case was traced to an outdoor location. All other cases were tied to indoor locations, with 79.9% of these being tied to households. This study underscores that sharing indoor space is a major SARS-CoV-2 infection risk.
150
150
100
100
5050
0 0
Entertainment Health club (aerobics)
Restaurant
Hotel room
Meeting rooms
Cruise ship Train and high speed rail cabins Passenger planes
Public bus
AUG 10, 2020
Metro and metro station
Entertainment Entertainment Health Health club club (aerobics) (aerobics)
Restaurant Restaurant 16°C-22°C,≥20% RH (winter) 24°C-28°C, ≤60% RH (summer) Hotel room room Hotel
Meeting rooms rooms Meeting
Cruise ship Cruise ship Train and high 22°C (winter) Train and 27°C, high speed rail cabins 50% RH (summer) speed rail cabins Passenger planes 26°C-28°C (summer) Passenger planes 18°C-20°C (winter) 40%-80% RH Public bus Public bus Metro and metro stationand metro Metro <30°C when outdoor 38°Cstation >5°C (7 for new bus) (Summer);≥12°C (Winter) Metro station: <30°C; 40%-70%
10.3 (ASHRAE) (800-2500 ppm) *2 10 (GB) 10.8 (ASHRAE) (17503500 ppm) *2
16°C-22°C,≥20%RH RH 16°C-22°C,≥20% (winter) (winter)24°C-28°C, 24°C-28°C, ≤60% ≤60% RH RH(summer) (summer)
2.5 (GB) 22°C3.1 (winter) 27°C, (ASHRAE) 22°C (winter) 27°C, 50% RH (summer) 50% RH (summer)
26°C-28°C 8 (summer) 26°C-28°C (summer) 18°C-20°C (winter) >40% of the total 18°C-20°C (winter) 40%-80% RH air RH 40%-80%
1500 ppm <30°C when outdoor 38°C >5°C for new <30°C when(7outdoor bus) 4.7 (at 2438 38°C(Summer);≥12°C >5°C (7 for new m) (Winter) bus) (Summer);≥12°C (FAR) 3.5 in air (Winter)(ASHRAE) 9.4 on Metroground station:(ASHRAE) <30°C; 40%-70% Metro station: <30°C; 40%-70%
2.8
ASHRAE62.1-2004 intimate 1.01.0 intimate 0.32 0.32 m m ASHRAE62.1-2004 (ASHRAE) intimate 0.32 m ASHRAE62.1-2004 (ASHRAE)
(GB)10.8 10.8 1010(GB) (ASHRAE)(1750(1750(ASHRAE) 0.4 3500ppm) ppm) 3500 *2*2
0.40.4 (ASHRAE) (ASHRAE)
4.1(GB) (GB)or or 6.4-6.9 4.1 6.4-6.9 (JGJ) (JGJ)5.15.1(ASHRAE) (ASHRAE) (500-900 ppm) *2*2 (500-900 ppm) 0.8-1.0 (JGJ)
0.8-1.0 0.8-1.0 (JGJ)(JGJ) 0.70.7 (ASHRAE) (ASHRAE)
(ASHRAE)
(ASHRAE)
4.1 (GB) or 6.4-6.9 (JGJ) 5.1 (ASHRAE) (500-900 ppm) *2
8.3 (GB) 5.5 (ASHRAE) (4001000 ppm) *2
10.3(ASHRAE) (ASHRAE) 10.3 (800-2500 ppm) 1.0 (800-2500 ppm) *2*2
0.10.1 (ASHRAE) (ASHRAE)
0.50.5 (ASHRAE) (ASHRAE)
GB50736-2012 GB50736-2012 JGJ64-2017 JGJ64-2017 ASHRAE62.1-2004 ASHRAE62.1-2004
GB50736-2012 JGJ64-2017 ASHRAE62.1-2004
intimate 0.32m intimate 0.32m +social 1.35m +social 1.35m
intimate 0.32m +social 1.35m
0.1 (ASHRAE)
2.5 2.5(GB) (GB) 3.1 3.1(ASHRAE) (ASHRAE)
intimate 0.32m intimate 0.32m +social 1.35m +social 1.35m
Sorokowska et al. et al. Sorokowska (2017)(2017)
GB50736-2012 social 1.35 m social 1.35 mSorokowska et al. BS EN social 1.35 m BS EN (2017) ISO7527:2004
8 (ASHRAE) 8 of 0.5 >40% the total air>40% of the total air
50
0 3
3
3
4
4
4
5
5
5
6
6 7
7 8
6 per outbreak 7 CasesCases per outbreak
Cases per outbreak
8 9
8
9 ≥10
9
≥10
≥10
Figure2: source (1) Distribution all identified 318 outbreaks forcategory each category Figure2: source (1) Distribution of all of identified 318 outbreaks for each of 416 the 416 venues. of the venues.
Figure2: source (1) Distribution of all identified 318 outbreaks for each category of the 416 venues.
GB50736-2012 GB50736-2012 ASHRAE62.1-2004 ASHRAE62.1-2004
GB50736-2012 GB50736-2012 ASHRAE62.1-2004 GB50736-2012
social 1.35 1.35 m m social
100
GB50736-2012 GB50736-2012 ASHRAE62.1-2004 ASHRAE62.1-2004
GB50736-2012 ASHRAE62.1-2004
intimate 0.32m +social 1.35m
0.7 (ASHRAE)
8.3 8.3(GB) (GB)5.55.5 (ASHRAE) (ASHRAE)(400(4001000 *2*2 1000ppm) ppm)
social social 1.35 1.35 m m
social 1.35 m
150
ISO7527:2004
All
All
HomeHome
Transport All Transport Restaurant
HomeRestaurant Entertainment
1500 ppm 1500 ppm
1.35 m TB/T1932-2014 social 1.35 m socialsocial BS EN 1.35 m TB/T1932-2014 ISO7527:2004
4.7 (at 2438 m) (FAR) 3.5 2438 in air m) 4.7 (at (ASHRAE) (FAR) 3.59.4inon air ground (ASHRAE) (ASHRAE) 9.4 on ground (ASHRAE) 2.8 2.8 Metro station: 8.3 (ventilation system on 3.5 (off or when MetroAC) station: 8.3train: (ventilation using Subway 2.8 system on with 3.5 (off or when with AC 5.6 mechanical using AC) Subway train: 2.8 ventilation with AC 5.6 with mechanical ventilation 8
social 1.35 m
FAR14CFR25.831 ANSI/ASHRAR16 FAR14CFR25.831 1-2007 ANSI/ASHRAR16 TB/T1932-2014 1-2007 CJ/T134-2001
8
8
Train: 5
Train: 5
Metro station: 8.3 (ventilation system on 3.5 (off or when 5 using AC) Subway train: 2.8 MANUAL OFTrain: PHYSICAL DISTANCING with AC 5.6 with mechanical ventilation
GB7258-2012 CJ/T134-2001 FAR14CFR25.831 ANSI/ASHRAR16GB7258-2012 1-2007 GB50157-2013
DB11/GB50157-2013 995-2013 GB/T7928-2003 DB11/ 995-2013 CJ/T134-2001 GB/T7928-2003
Entertainment Transport Shopping
Shopping Restaurant
Miscellaneous Miscellaneous
Entertainment Shopping Miscellaneous
*1) For estimation of ventilation rates in standards when air change rate(ACH) is *1) For ventilation specified, weestimation consider aof room to be 3mrates high.in standards when air change rate(ACH) is specified, we consider a room to be 3m high. *2) Ye W, Wang H, Zhang X. Preliminary discussion on ventilation rates for public in China. Proceedings of COBEE 2018. 2018 Feb 5-9, Austin. *2)buildings Ye W, Wang H, Zhang X. Preliminary discussion on ventilation rates for public buildings in China. Proceedings of COBEE 2018. 2018 Feb 5-9, Austin.
GB7258-2012
*1) For estimation of ventilation rates in standards when air change rate(ACH) is specified, we consider a room to be 3m high.
GB50157-2013 DB11/ 995-2013 GB/T7928-2003
*2) Ye W, Wang H, Zhang X. Preliminary discussion on ventilation rates for P. 19 public buildings in China. Proceedings of COBEE 2018. 2018 Feb 5-9, Austin.
ANALYSIS OF GRADIENT OF EXPOSURE Risk of gathering in groups No carnival No carnival Carnival No carnival No carnival Carnival Carnival Carnival
infection in a German community with a super-spreading event.
https://www.medrxiv.org/content/10.1101/2020.05.04.20090
This study examined the nature of the spread in the Gangelt community (12,597 inhabitants) in Heinsberg Germany after a superspreading event during carnival festivities â&#x20AC;&#x153; Kappensitzungâ&#x20AC;? that was on February 15, 2020, just before the city went into lockdown. The data was collected from 405 households incorporating 919 individuals, 15.5% were infected, which is roughly 5 times higher than the number officially reported for this community (3.1%).
According to this study there was a significant positive association between celebrating carnival and infection status No carnival Infectionrate rate (%) Infection
0 0 0
Carnival
No carnival No carnival No carnival 0
10
20
30 30 30
p<0.001 30 p<0.001 p<0.001
Carnival Carnival Carnival No carnival Estimated mean number of symptoms in infected participants not celebrating carnival and in infected participants celebrating carnival. Point estimates (filled circles) and CIs were obtained by fitting a quasi-Poisson model with the number of symptoms as response variable and carnival (yes/no) asp<0.001 a factor covariable. The quasi-Poisson model was used instead of a Poisson GEE model because the number of households was large relative to the number of analyzed study participants
No No carnival No carnival carnival Carnival Carnival Carnival No carnival
0 0 0
0
1 1 1
1
Number of symptoms in infected Number of2symptoms in infected Number of symptoms3in infected 4 Number 2 of symptoms3in infected 4 2 3 4
Number of symptoms in infected 2 3 4
5 5 5
5
p=0.007 p=0.007 p=0.007
p=0.007 P* value: Is an index to measure the strength if evidence, it stands for probability and measures how likely it is that any observed difference between groups is due to chance. Values close to 0 indicate that the observed difference is unlikely to be due to chance, whereas a P value close to 1 suggests no difference between the groups other than due to chance. Based on the idea and practice of statistician Fisher developed in 1930s. He advocated P<0.05 (5% significance) as a standard level for concluding that there is evidence against the hypothesis tested, though not as an absolute rule (Source 2). Carnival
AUG 10, 2020
20 20 20
Infection rate (%)
Carnival
Source 2: Dahiru Tukur. ( June, 2008). P-Value, A true test of statistical significance? A cautionary note. NCBI (US National Library of Medicine National Institutes of Health). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4111019/
10 Infection rate (%) Infection rate (%) 10 10
MANUAL OF PHYSICAL DISTANCING
0 10 20 30 % 40 % 40 0 10 20 30 Raw percentages of infected participants celebrating carnival, grouped by their numbers 15of 0 Number above bars indicate the total number of indviduals in the respective group. symptoms. 15 13 0 15 13 0 4 13 1 4 7 4 1 0 % 40 10 20 30 7 1 6 7 2 116 15 6 2 0 11 2 116 13 3 6 6 4 3 6 1 6 3 7 6 1 4 1 8 6 4 1 2 8 4 11 3 8 5 3 9 6 5 3 3 9 5 6 9 1 6 1 5 1 6 1 4 5 6 8 53 7 53 3 7 3 5 5 7 9 1 5 8 1 9 8 11 6 9 8 5 9 1 9 1 6 3 9 1 7 6 0 9 5 6 0 10 0 1 3 10 8 3 10 9 1 3 11 1 0 11 11 9 11 0 6 0 0 Number symptoms infected Number ofofsymptoms Number Number ofofinfected Number of of symptoms symptoms of symptoms of of infected infected of infected
Source 1: Hendrik Streeck, Bianca Schulte, Beate Kuemmerer, Enrico Richter, Tobias Hoeller, Christine Fuhrmann, Eva Bartok, Ramona Dolscheid, Moritz Berger, Lukas Wessendorf, Monika Eschbach-Bludau, Angelika Kellings, Astrid Schwaiger, Martin Coenen, Per Hoffmann, Markus Noethen, Anna-Maria Eis-Huebinger, Martin Exner, Ricarda Schmithausen, Matthias Schmid, Gunther Hartmann. ( June 02, 2020). Infection fatality rate of SARS-CoV-2
This community spread case study during carnival festivities indicated that physical proximity combined with vigorous vocal activity intensified the transmission of the virus and % 40 0 10 20 the infected. 30 exacerbated the symptoms among
10
11
3 1 0
P. 20
ANALYSIS OF GRADIENT EXPOSURE Estimated Inactivation of COVID-19 by Solar Radiation Jose-Luis Sagripanti and C. David Lyle. (June 5, 2020). Estimated Inactivation of Coronaviruses by Solar Radiation With Special Reference to COVID-19 Wiley Online Library. https://onlinelibrary.wiley.com/doi/10.1111/php.13293 This study estimates the solar inactivation of the SARS-CoV-2 virus by solar ultraviolet radiation in several cities of the world during different times of the year. The outdoor persistence of the virus is dependent on temperature, humidity, and contribution of sunlight, with ultraviolet radiation being the primary virucidal agent in the environment. Testing both aerosolaized and surface deposited viral particles in a two hour window near the time of high noon revealed that sunlight should have a role in the occurrence, spread rate, and duration of the virus. The virus stays notably more active for a longer duration in the winter in many temperate zone cities with continued risk for re-aerosolization and human infection. Meanwhile, in the summer, the affects of UV radiation are likely to substantially decrease the length of time needed for the virus to become inactive.
This study estimates, based on SARS-CoV-2 virus, that sunlight and humidity and can shorten the time need for virus to become inactive. Effectiveness estimated for inactivation of SARS-CoV-2 virus by solar radiation
City Latitude Miami, FL 25.8 °N Houston, TX 29.8 °N
.51/14 0.34/20 0.41/17
0.13/53
0.44/16 0.25/28 0.33/21
Dallas, TX 32.8 °N
0.39/18
Phoenix, AZ 33.4 °N
0.39/18
Atlanta, GA 33.7 °N
0.39/18
Summer Solstice Spring Equinox Fall Equinox Winter Solstice
0.08/86
0.20/34 0.28/25
0.06/115
0.19/36 0.26/27
0.05/138
0.18/38 0.26/27
Los Angeles, CA 34.1 °N
0.05/138
0.38/18
0.18/38 0.26/27
San Francisco, CA 37.7 °N
0.34/20
Washington, D.C. 38.9 °N
0.33/21
Philadelphia, PA 39.9 °N
0.32/22
New York City, NY 40.7 °N
0.32/22
Chicago, IL 41.9 °N
0.31/22
Boston, MA 42.3 °N
0.30/23
Detroit, MI 42.3 °N
0.30/23
Toronto, Ontario 43.6 °N
0.29/24
Minneapolis, MN 45.0 °N
0.28/25
0.05/138 0.13/53
0.20/34
0.03/230 0.12/57
0.19/36
0.02/>300 0.11/63
0.18/38
0.02/>300 0.10/69
0.17/41
0.02/>300 0.10/69
0.16/43
0.01/>300 0.09/77
0.15/46
0.01/>300 0.09/77
0.15/46
0.01/>300 0.08/86
0.14/49
0.01/>300 0.07/99
0.13/53
Seattle, WA 47.6 °N
0.01/>300
0.26/27
0.06/115
0.11/63
0
25
50
0.01/>300
75
100
125
150
175
200
225
250
275
300
Time for 90% Infectivity reduction (min) Solar Virucidal UV Flux (J/m² 254 ²/min) AUG 10, 2020
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P. 21
ANALYSIS OF GRADIENT EXPOSURE Urban Density Is Not Linked to Higher Infection Rates
This analysis looks to challenge the assumption that densely populated cities are site of greater risk than areas of population sprawl. It finds that its dense urban areas are associated actually with lower Covid-19 death rates.
Shima Hamidi, Sadegh Sabouri, and Reid Ewing. (June 18, 2020). Does Density Aggravate the COVID-19 Pnademic? Taylor & Francis Online.
913 counties in the U.S. with at least one COVID-19 death as of May 25 (Basis of study)
https://www.tandfonline.com/doi/full/10.1080/01944363.2020.1 777891 Though it is assumed that dense areas lead to more face-to-face interaction among residents, which makes them potential hotspots for the rapid spread of pandemics, this study suggests that dense urban areas are associated with lower COVID-19 death rates. When accounting for other factors like race and education, it was found that density was not significantly associated with county infection rate. Rather, the higher level of development that comes with dense urban centers likely contributed to more developed healthcare systems that aided in the lowering of death rates in those regions. The findings suggest that connectivity matters more than density in the spread of the COVID-19 pandemic. Large metropolitan areas with a higher number of counties tightly linked together through economic, social, and commuting relationships are the most vulnerable to the pandemic outbreaks. “These findings suggest that urban planners should continue to practice and advocate for compact places rather than sprawling ones, due to the myriad well-established benefits of the former, including health benefits.” -- Shami Hamidi “The fact that density is unrelated to confirmed virus infection rates and inversely related to confirmed COVID-19 death rates is important, unexpected, and profound.” -- Shami Hamidi
Density
• Counties have significantly lower death rates due to better healthcare systems • Easier management of social distancing interventions such as sheltering in place • Compact development allows for more concentrated responses to the virus
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MANUAL OF PHYSICAL DISTANCING
Urban and Metropolitan Centers
Connectivity and Sprawl
• Virus spread is facilitated by suburban sprawl through the connection between a major urban hub and its surrounding geographic units • Mega regions connecting adjacent cities are incubators of pandemic outbreaks • Low density areas have less access to quality health care
P. 22
ANALYSIS OF GRADIENT EXPOSURE Urban Density Is Not Linked to Higher Infection Rates (continued)
NEW YORK
Shima Hamidi, Sadegh Sabouri, and Reid Ewing. (June 18, 2020). Does Density Aggravate the COVID-19 Pnademic? Taylor & Francis Online.
Ulster (1/87)
Litchfield (1/113) Dutchess (1/65)
CONNECTICUT
Sullivan (1/51)
https://www.tandfonline.com/doi/full/10.1080/01944363.2020.1 777891 The perception of viral transmission is that there is a higher rate in areas with higher density. However, data from the New York Metropolitan area, including parts of New York State, Connecticut, New Jersey, and Pennsylvania shows suburban counties adjacent to New York City with a higher numbers of reported cases. Counties with a higher case count than New York City are Rockland, Westchester, Passaic, Nassau, Hudson, Suffolk, and Orange. While these counties have a significantly lower density than New York City, they are immediately reliant on the interstate highway system and public transit networks that facilitate the movement of goods and people through the region. These networks likely allow the virus to travel greater distances more quickly.
PENNSYLVANIA
Orange (1/35)
New Haven (1/66)
Putnam (1/69)
Pike (1/106)
Fairfield (1/53) Westchester (1/27) Rockland (1/23)
Sussex (1/105)
Passaic (1/28) Bergen (1/45) Morris (1/67)
Suffolk (1/34)
Essex (1/40)
Nassau (1/31)
Hudson (1/34) Hunterdon (1/104) Somerset (1/62)
New York City (1/37)
MIddlesex (1/46)
Mercer (1/45)
Monmouth (1/60)
NEW YORK METROPOLITAN AREA Share of Population with a reported case August 3, 2020
NEW JERSEY Ocean (1/58) 1 in 200
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
1 in 100
1 in 30
P. 23
March March 05, 2020 05, 2020 March March 06, 2020 06, 2020
ANALYSIS OF GRADIENT OF EXPOSURE Spread by singing-case study
IndexIndex patient patient
March March 07, 2020 07, 2020
This specific case study of a choir practice rehearsals in WA, indicated that physical proximity combined with vigorous vocal activity intensified the transmission of the virus.
March March 08, 2020 08, 2020 March March 09, 2020 09, 2020
ChoirChoir practice practice
March March 10, 2020 10, 2020 March March 11, 2020 11, 2020
Hamner L, Dubbel P, Capron I, et al ( May 12, 2020). High SARSCoV-2 Attack Rate Following Exposure at a Choir Practice â&#x20AC;&#x201D; Skagit County, Washington, March 2020 DOI: http://dx.doi.org/10.15585/mmwr.mm6919e6
March March 12, 2020 12, 2020 Confirmed and probable cases of COVID 19 associated with two choir practices, by date of symptom onset ( N=53) March March 13, 2020 13, 2020 Confirmed and probable cases of COVID 19 associated with two choir practices, by date of symptom onset ( N=53) March March 14, 2020 14, 2020
Probable
March March 15, 2020 15, 2020
Confirmed
This report explored the spreading event of SARS-CoV-2 at a choir practice in Skagit County, Washington during March, 2020. After a choir practice of 61 people with one symptomatic person, 32 were confirmed and 20 probable secondary Covid-19 cases developed. Three patients were hospitalized and two died. The report indicates that transmission was likely due to physical proximity between members of the choir (distance within 6 feet of each other) while practicing and likely exacerbated by singing. Singing spreads the virus through the air especially in closed environments.
Choir practice
Index patient
Choir practice
Confirmed and probable cases of COVID 19 associated Probable Confirmed Date of symptom onset March 01, 2020 Choir practice
Index patient
4
6
8
10
March 15, 2020 March 16, 2020
March 03, 2020
March 17, 2020
March 04, 2020
March 18, 2020
12
Seat spacing
14
16
18
March 09, 2020 March 10, 2020
March 22, 2020 Date of symptom March 23, 2020 onset March 01, 2020 March 24, 2020
Incubation
20
0
2
4
6
8
Median interval from exposure during March 10 practice to onset of symptoms
53.3% 53.3% 53.3% among among confirmed confirmed casescases Among confirmed
86.7% 86.7% 86.7% among among all cases all cases cases Among all
cases
Incubation Attack rate ( 53.3% and 86.7& among confirmed cases and all cases, respectively) Incubation Higher than what is seen in other 0 cluster 2 superspreading 4 6 8events 10 12 14
Seat spacing
Median incubation period of Covid 19
6"-10"
Median interval from exposure during March 10 practice to onset of symptoms
2
4
6
8
March 02, 2020 March 25, 2020 March 11, 2020 Choir practice March 03, 2020 March 26, 2020 March 12, 2020 March 04, 2020 March 27, 2020 March 13, 2020 March 05, 2020 March 28, 2020 March 14, 2020 March 06, 2020 March 29, 2020 Index patient March 07, 2020 March 30, 2020 March 16, 2020 March 08, 2020 March 17, 2020 March 09, 2020 March 18, 2020 Choir practice March 10, 2020 March 19, 2020 MANUAL OF PHYSICAL DISTANCING March 11, 2020 March 20, 2020
10
12
14
16
18
20
Seat spacing Seat Spacing
53.3% among confirmed cases
6"-10"
Incubation 86.7% among all cases
0
2
4
Median incubation period of Covid 19
Median interval from exposure during March 10 practice to onsetrespectively) of symptoms Attack rate ( 53.3% and 86.7& among confirmed cases and all cases, Higher than what is seen in other cluster superspreading events
March 15, 2020
AUG 10, 2020
1
Median incubation period of Covid 19
6"-10"
March 19, 2020 March 05, 2020 Confirmed and probable cases of COVID 19 associated with two choir practices, by date of symptom onset ( N=53) March 20, 2020 March 06, 2020 Number of new cases March 21, 2020 March 07, 2020Probable Confirmed March 08, 2020
Choir practice
Number of new cases 2
Date of March March 16,symptom 2020 16, 2020 onset March March 17, 2020 17, 2020 March 01, 2020 March March 18, 2020 18, 2020 March 02, 2020 March March 19, 2020 19, 2020 March 03, 2020 March March 20, 2020 20, 2020 March 04, 2020 March March 21, 2020 21, 2020 March 05, 2020 March March 22, 2020 22, 2020 March 06, 2020 March March 23, 2020 23, 2020 March 07, 2020 March March 24, 2020 24, 2020 March 08, 2020 March March 25, 2020 25, 2020 March 09, 2020 March March 26, 2020 26, 2020 March 10, 2020 March 27, 2020 27, 2020 by date of symptom onset ( N=53) with twoMarch choir March 11,practices, 2020 March March 28, 2020 28, 2020 March 12, 2020 Number of new cases March March 29, 2020 29, 2March 4 6 2020 8 10 12 14 16 18 20 13, 2020 March March 30, 2020 30, 2020 March 14, 2020
March 02, 2020
Attack Attack rate (rate 53.3% ( 53.3% and 86.7& and 86.7& among among confirmed confirmed casescases and all andcases, all cases, respectively) respectively) Attack rate ( 53.3% and 86.7& among confirmed cases and all cases, respectively) Higher Higher than than whatwhat is seen is seen in other in other cluster cluster superspreading superspreading events events Higher than what is seen in other cluster super spreading events
P. 24
6
ANALYSIS OF GRADIENT OF EXPOSURE Indoor environment air flow-case study On January 24, a total of 91 individuals (83 customers 8 staff members) were in the restaurant
This early release article from CDC about a restaurant in Guangzhou, China looked to determine the unique pattern of the outbreak in that space. Three unrelated families, sitting at three tables became infected, whereas none of the staff or the other patrons at other tables became infected. The paper determined that the infection was consistent with the spread pattern of exhaled virus-laden aerosols associated to poor ventilation over an extended period of sitting.
Glass screen
Glass screen
19'-10 " Distance from index patient>3’-0”
Among 83 customers , 10 became ill with COVID 19
B1 Feb 1
3rd floor dining area 1561 sqft (145 sqm)in 5 floor building
B2 Feb 5
Family B
Exhaust fan
No windows, air conditioned space
B3 Feb 5
A3 Jan 29
Family A
A5 Feb 2
A4 Jan 29
Family C
A2 Jan 27 C2 Jan 24
D
53 Min Family A and family B overlapping period since seating of 53 minutes
E
F
Family C
27'-2"
Family A
Air outlet and return air inlet for the central air conditioner
Air conditioner
Family B
C1 Jan 24
A1 Jan 24
13'-6 "
DOI: 10.3201/eid2607.200764
Air conditioner
Source 1: Lu J, Gu J, Li K, Xu C, Su W, Lai Z, et al. COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. CDC
The following illustrates factors of risk of exposure in enclosed environment without windows and with mechanical air conditioning, those factors are air flow, density and duration of exposure
Family A and family C overlapping period since seating of 73 minutes 73 Min
6’ 5’ 4’ 3’ 2’ 1’
CDC recommeneded social distance
Access to bathroom
Stair
Throat swab samples from contacts and 6 smear samples from the air conditioner (3 from the air outlet and 3 from the air inlet) were negative for SARS-CoV2
Elevator
27'-3”
Figure: Source 1, Redrawn by author. AUG 10, 2020
Checkout counter
MANUAL OF PHYSICAL DISTANCING
0
1'
3'
6'
P. 25
ANALYSIS OF GRADIENT OF EXPOSURE Indoor environment-case study
This study demonstrated how the combination of physical proximity and extended duration in an interior office space raises the risk of infection.
11th floor 10th floor 9th floor
Park SY, Kim YM, Yi S, et al. ( April 23, 2020). Coronavirus Disease Outbreak
in Call Center, South Korea. Emerging Infectious Diseases.
This case study examined a call center in Seoul, South Korea and the infection pattern related to spatial proximity in the office on a specific floor. While the building had an overall infection rate of 8.5%, this floor had a rate of 43.5% and tied to a specific side of the floor. Despite office workers moving around the building, and using common facilities, the infection pattern demonstrated the role that proximity within indoor 23 environments over a duration play in increasing infection 22 risk.
23
Figure: Source 1, Epidemic curve of a corona virus disease outbreak in call center, by date of symptom onset, Seoul, Korea, 2020. Asymptomatic cases are excluded.
22 21 20 18
11th floor 11th floor
17 16
10th floor 10th floor 9th 9thfloor floor
15 14 13 12 11 10 9 8 7
21
6
20
5 3
18
Evaluation of ventilation system
Closure of building
4
19
2
17
1 10 11 12 13 14 15 16 17 18 19 20 21 22
16
Confirmed cases
Closure of building
19
Confirmed cases
DOI: 10.3201/eid2608.201274
23
24
25 26 27 28 29
1
2
3
4
5
6
7
8
Testing
14 12
10 11 12 13
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
29 30 31
March 2020
15 13
9
February 2020
Date of symptom onset
Text message to all visitors
Figure: Source 1, 11th floor plan in a mixed use 19 storey building.
11 10 9 8 7
Seating of confirmed cases Seating of employees who werenâ&#x20AC;&#x2122;t confirmed cases of COVID 19
6
Evaluation of ventilation system
5 4 3 2 1 10 11 12 13 14 15 16 17 18 19 20 21 22
23
24
25 26 27 28 29
1
2
3
4
5
6
7
8
9
10 11 12 13
February 2020
29 30 31
March 2020 Testing
Date of symptom onset
AUG 10, 2020
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
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Text message to all visitors
P. 26
ANALYSIS OF GRADIENT OF EXPOSURE Efficacy of mask wearing
This article summarizes the evidence that makes clear that wearing masks is essential to reduce the transmission of Covid-19 in both droplet and aerosol form. This is especially important given the asymptomatic nature of covid infection and the highly transmissible nature of asymptomatic persons.
K. A. Prather et al ( May 27, 2020). Reducing transmission of SARS-CoV-2. Science. DOI: 10.1126/science.abc6197
Healthy
Infected, asymptomatic
The article discussed the role of COVID-19 transmission via airborne route by asymptomatic infected individuals, the role of universal mask wearing in order to reduce asymptomatic spread of COVID 19 via aerosols and droplets. In addition, the essay discusses the key factors for evaluating risk in indoor versus outdoor environment. Critically, the article makes the clear case that maskwearing is an essential protective and preventative measure. â&#x20AC;&#x153;Masks provide a critical barrier, reducing the number of infectious viruses in exhaled breath, especially of asymptomatic people and those with mild symptoms. Surgical mask material reduces the likelihood and severity of COVID-19 by substantially reducing airborne viral concentrations. Masks can also protect uninfected individuals from SARS-CoV-2 aerosols and droplets. Thus, it is particularly important to wear masks in locations with conditions that can accumulate high concentrations of viruses, such as health care settings, airplanes, restaurants, and other crowded places with reduced ventilation. The aerosol filtering efficiency of different materials, thicknesses, and layers used in properly fitted homemade masks was recently found to be similar to that of the medical masks that were tested. Thus, the option of universal masking is no longer held back by shortages.â&#x20AC;?
Maximum exposure
Minimum exposure
Figure: Source 1. Redrawn by MPD author
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 27
erosols vaibility NO MASK
HOMEMADE MASK
SURGICAL MASK
NO STUDIES
N95 RESPIRATOR
LARGER THAN 10 μm DROPLET PARTICLES CAN BE BLOCKED
vaibility ANALYSIS OF GRADIENT OF EXPOSURE
ELASTOMERIC RESPIRATOR
BLOCKS 95% OF DROPLETS AS SMALL AS 0.3 MICRONS
BLOCKS 95% OF DROPLETS AS SMALL AS 0.3 MICRONS REUSABLE, REPLACABLE FILTERS
The effectiveness of masks varies broadly based on type, material composition and tightness of fit. Masks have been shown to be effective at reducing larger droplet spread associated with transmission of coronavirus related pathogens. It is less clear how effective masks are in reducing aerosol transmission and in providing personal protection to the wearer.
Efficacy of mask wearing WHO CLASSIFICATION OF INFECTIOUS RESPIRATORY DROPLETS WHO classification of infectious WHO CLASSIFICATION OF> INFECTIOUS DROPLETS 5 μm* respiratory droplets RESPIRATORY DROPLETS Droplets > 5 μm > AEROSOL DROPLETS 5 μm* < 5 μm* Inward
−6
micrometer (10 Aerosol < 5 μm < 5μm: AEROSOL μm*
Outward
INWARD
OUTWARD
)m
The average human hair diameter is about 70 micrometers
−6 osols vaibility μm: micrometer (10 ) m μm: micrometer (10
-6
)m
The average human hair diameter about The average human hair isdiameter is about 70 micrometers 70 micrometers
Inhalation Inward protection (Individual protection)
Exhalation
MASK
MASK Outward protection (Protecting others)
INWARD PROTECTION ( INDIVIDUAL PROTECTION )
WHO CLASSIFICATION OF INFECTIOUS RESPIRATORY DROPLETS
OUTWARD PROTECTION ( PROTECTING OTHERS)
DROPLETS > 5 μm*
AEROSOL < 5 μm* −6
μm: micrometer (10 ) m Homemade mask The average human hair diameter is about 70 micrometers Studies indicate simple cloth masks have NO MASK HOMEMADE that MASK
No mask
some efficacy on transmission though variations in material quality and fit prevent quantification
NO MASK
NO STUDIES
HOMEMADE MASK
Source 1: US. Food & Drug Administration . (April, 04, 2020) N95 RespiraNO STUDIES tors and Surgical Masks (Face Masks) https://www.fda.gov/medical-devices/personal-protective-equipment-infection-control/n95-respirators-and-surgical-masks-facemasks
Surgical mask Surgical masks SURGICAL MASKprovides 77% protection. (Source 3). The edges of the mask don’t form a seal around the nose and mouth (Source 3*).
LARGER THAN 10 μm DROPLET
PARTICLES CAN BE BLOCKED SURGICAL MASK Risk Level LARGER THAN 10 μm DROPLET PARTICLES CAN BE BLOCKED
N95 respirator
Elastomeric respirator
Blocks 95% of droplets as small as 0.3 N95 RESPIRATOR microns. (Source 1)
Blocks 95% of dropletsRESPIRATOR as small as 0.3 miELASTOMERIC crons, reusable, replacable filters. (Source 1)
BLOCKS 95% OF DROPLETS
AS SMALL AS 0.3 MICRONS N95 RESPIRATOR BLOCKS 95% OF DROPLETS AS SMALL AS 0.3 MICRONS
Less
BLOCKS 95% OF DROPLETS AS SMALL
AS 0.3 MICRONS REUSABLE, ELASTOMERIC RESPIRATOR
REPLACABLE FILTERS BLOCKS 95% OF DROPLETS AS SMALL AS 0.3 MICRONS REUSABLE, REPLACABLE FILTERS
Source 2: Howard, J.; Huang, A.; Li, Z.; Tufekci, Z.; Zdimal, V.; van der Westhuizen, H.; von Delft, A.; Price, A.; Fridman, L.; Tang, L.; Tang, V.; Watson, G.L.; Bax, C.E.; Shaikh, R.; Questier, F.; Hernandez, D.; Chu, L.F.; Ramirez, C.M.; Rimoin, A.W. (April, 12, 2020) Face Masks Against COVID-19: An Evidence Review. https://www.preprints.org/manuscript/202004.0203/v1
* Source 3: Mandavilli, Apoorva. (June, 01, 2020) Medical Workers Should Use Respirator Masks, Not Surgical Masks. The New York Times https://www.nytimes.com/2020/06/01/health/masks-surgical-N95-coronavirus.html?action=click&module=Top%20Stories&pgtype=Homepage AUG 10, 2020
INWARD MANUAL OF PHYSICAL DISTANCING INWARD
OUTWARD OUTWARD
P. 28
ANALYSIS OF GRADIENT OF EXPOSURE Efficacy of mask wearing UVC
UVB
100
Source 1: Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. (April 03, 2020). Respiratory Virus Shedding in Exhaled Breath and Efficacy of Face Masks. Nature https://www.nature.com/articles/s41591-020-0843-2
280
UVA 315
400
500
Ultraviolet
Coronavirus
Influenza virus
600
Droplet particles >5 µm
Virus strain tested 0%
This study evaluated the impact of surgical masks on transmission of seasonal corona virus, influenza and rhinoviruses in a group of symptomatic adults and children. The results demonstrated that surgical masks were effective in preventing the transmission of seasonal corona virus in both droplet and aerosol forms, with varying results for influenza and rhinoviruses. Seasonal corona virus is distinct from the SARS-CoV-2.
This study demonstrated that a surgical face mask reduced the transmission from infected persons of viral RNA associated with droplets and aerosols for seasonal corona virus. VISIBLE 700
750 nm
>5 μm
Detection of virus: No positive/ no. total (%) 10%
20%
HCoV-229E ( Alpha) * 90% Virus Inactivation Without surgical face mask 99% Virus Inactivation With surgical face99.9% mask 0 Virus of 11 ( 0%) Inactivation
30%
0.56
40%
1.1
60%
3 of 10 (30%)
1.7
6 of 23 (26%)
Without surgical face mask
HCoV-OC43 Beta)* 1 of 27 ( (4%) 90% Virus Inactivation 99% Virus Inactivation Without surgical face mask Virus Inactivation With surgical face99.9% mask With surgical face mask
Rhinovirus
0.39
Coronavirus
9 of 32 (28%)
6 of 27 (22%)
Virus strain tested Influenza A ( H1N1) HCoV-229E ( Alpha) * 90% Virus Inactivation 90% Virus Inactivation 99% Inactivation 99% Virus Virus Inactivation 99.9% Virus Inactivation 99.9% Virus Inactivation 0% HCoV-OC43 ( Beta)* 90% Virus Inactivation 99% Virus Inactivation 99.9% Virus Inactivation
0.78
0.56
1.2
Aerosol particles ≤5 µm
1.1
1.3
≤5 μm
Detection of virus:1.7No positive/ no. total (%)
10%
20% 0.39
0.78
30%
40%
1.2
60%
4 of 10 (40%)
Without surgical face mask
With surgical face mask Influenza 0 of A11( H1N1) ( 0%)
Influenza virus
90% Virus Inactivation 99% Virus Inactivation 99.9% Virus Inactivation
2.6
8 of 23 (35%)
Without surgical face mask With surgical face mask
Rhinovirus
1.3
3.8
6 of 27 (22%)
19 of 34 (56%)
Without surgical face mask
12 of 32 (38%)
With surgical face mask
25 min 25 min
This study evaluated the impact of surgical masks on individuals with 12 common respiratory viruses and subtypes including coronaviruses (NL63, OC43, 229E and HKU1), influenza A (nonspecific, H1 and H3) and B viruses, respiratory syncytial virus, parainfluenza virus (types 1–4), adenovirus, human metapneumovirus and enterovirus/rhinovirus. This study didn’t evaluate the impact of surgical masks on individuals with SARS-CoV2 99.9 %
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
99.9 %
P. 29
ANALYSIS OF GRADIENT EXPOSURE Universal Mask Usage to Prevent Infection
This study examines the critical role that the implementation of mask mandates have on significantly reducing Covid-19 transmission, using Mass General Brigham as case study.
John T. Brooks, MD; Jay C. Butler, MD; Robert R. Redfield, MD. (July 14, 2020). Universal Masking to Prevent SARS-CoV-2 Transmissionâ&#x20AC;&#x201D;The Time Is Now. JAMA Network.
No. of Healthcare Workers Tested Per Day Universal Masking for Healthcare Workers
https://jamanetwork.com/journals/jama/fullarticle/2768532
20-100
101-200
>200
Universal Masking for Patients
35 COVID-19 Positivity Rate in Mass General Brigham Healthcare workers (%)
Presented evidence suggests that universal mask usage by healthcare workers, essential workers, and the general public significantly reduces the rate of transmission of COVID-19. Prior to universal masking in late March, Mass General Brigham (MGB) the largest healthcare system in Massachusetts experienced an exponential rise in transmission rates. After implementing universal mask usage, the health network experienced a significant drop in transmission rates. While broad community wide initiatives, like a statewide declaration of emergency and hospital policies to restrict visitors resulted in decreased transmission, it was not until a week after universal mask usage for case transmission rate to decrease.
<20
30 25 20 15 10 5 P<.001 0 March 6
March 10
March 16
March 25
April 6
April 11
April 29
Date (2020) March 10: Massachusetts decares state of emergency March 16: Massachusetts closes schools
Interventions in Massachusetts
March 17 Massachusetts reduces public transportation March 24: Massachusetts stay-at-home order for nonessential workers March 12: MGB restrict visitors
Interventions in Mass General Brigham
March 14: MGB restrict elective procedures March 16: MGB restrict all business travel and limits on-site working March 25: MGB universal masking of healthcare workers April 6: MGB universal masking of patients
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 30
ANALYSIS OF GRADIENT EXPOSURE Universal Mask Usage to Prevent Infection (continued)
This study examines the important protective role that wearing masks have in a real-life case study, where two hairstylists that were infected wore masks, which is considered a key issue in the lack of transmission to the clients, based on contact tracing.
John T. Brooks, MD; Jay C. Butler, MD; Robert R. Redfield, MD. (July 14, 2020). Universal Masking to Prevent SARS-CoV-2 Transmissionâ&#x20AC;&#x201D;The Time Is Now. JAMA Network. https://jamanetwork.com/journals/jama/fullarticle/2768532 Another report from investigators in Missouri found that adherence to universal masking for source control as mandated by city ordinance and company policy helped prevent transmission. Two stylists at a hair salon in Springfield, MO tested positive for the virus after serving 139 clients, but they were required to wear masks at all times. Public health contact tracing revealed that after two weeks no symptoms of COVID-19 were identified among the exposed clients. Furthermore, among the 104 clients interviewed, 102 were wearing face masks.
AUG 10, 2020
139 Total Clients Client interviewed for contact tracing who wore mask (102) Client interviewed for contact tracing who did not wear mask (2) Client not interviewed for contact tracing (35)
MANUAL OF PHYSICAL DISTANCING
Hairstylists Tested Positive for COVID-19
P. 31
ANALYSIS OF GRADIENT OF EXPOSURE Recommendation for air change per hour (ACH)
The 2003 CDC guidelines for air changes per hour to achieve a 99% or 99.9% efficiency in a health care facility indicates a relatively high amount of air changes over half an hour or more. This study assumes no aerosol generating person is in the room.
Source 1: CDC. Appendix B Air, table B.1
https://www.cdc.gov/infectioncontrol/guidelines/environmental/ appendix/air.html Time required for airborne containment removal in relation to air changes per hour rate (ACH) and time required for airborne containment removal by efficiency
The CDC provides guidelines for health care facilities and site for determining the relationship between air changes per hour and the amount of time that is necessary for a given space to have contaminants in air removed. This ratio means that the lower the ACH, the more time it will take for the room to meet a theoretical cleaning efficiency, demonstrated as 99% or 99.9%. This chart is based on a mathematical model and does not include variables such as human occupancy, or other sources of contamination. The guidelines were issued in 2003 and are not specific to Covid-19.
60 mins ( 1 hr)
Air Change/ Hour (ACH)
120 mins ( 2 hr)
180 mins ( 3 hr)
240 mins ( 4 hr)
300 mins ( 5 hr)
2 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
138 mins
207 mins
4 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
Empty room With no aerosol generating source
69 mins
104 mins
+
6 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
46 mins
69 mins
8 ACH 52 mins 35 mins
EFFICIENCY > 99.9% EFFICIENCY > 99%
+ 10 ACH 41 mins 28 mins
EFFICIENCY > 99.9% EFFICIENCY > 99%
+
12 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
35 mins 23 mins
+ 15 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
28 mins 18 mins
20 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
21 mins 14 mins
50 ACH EFFICIENCY > 99.9% EFFICIENCY > 99%
8 mins 6 mins
+ Denotes cited ACH for patient care areas
AUG 10, 2020
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P. 32
Ventilation systems Ventilation can systems be controlled; can behence controlled; ventilatilation hence ventilatilation presents a major presents engineering a major method engineering to controlthe method to spread controlthe of spread of pathogens inpathogens hospital and in hospital other environments. and other environments.
ANALYSIS OF GRADIENT OF EXPOSURE Local air patterns influence risk rates Source 1: Pantelic Jovan & Tham Kwok Wai. ( 2013). Adequacy of air change rate as the sole indicator of an air distribution system’s effectiveness to mitigate airborne infectious disease transmission caused by a cough release in the room with overhead mixing ventilation: A case study ,
Air change rate (ACH) can’t be assumed as the sole factor of air delivery system in diluting contaminants, instead it should be considered in conjunction with other factors such as local Ventilation systems can be controlled; hence ventilatilation presents a major engineering method to controlthe spread of pathogens in hospital and other environments. air flow pattern as shown in this study.
Airflow patterns Airflow in indoor patterns environment in indoor environment are generatedare bygenerated : by :
A field environmental A field environmental chamber (FEC) chamber was used (FEC) as was an experimental used as an experimental facility in thisfacility study in with this anstudy air handling with an unit air handling (AHU) unit (AHU) that suppliedthat a combination supplied a combination of recirculated of and recirculated outdoor and air tooutdoor the FEC. airTracer to the decay FEC. Tracer methods decay were methods used towere measure used to measure Airflow generated patterns bygenerated ventilationby ventilationtotal ventilation, - The ventilaton - The system. ventilaton system.Airflow patterns totaland ventilation, leakage and air change leakagerates air change in the FEC. ratesThe in the FEC FEC. simulated The FEC office simulated environment office environment with ceiling mounted with ceiling mounted systems can systems be controlled can be controlled diffusers. Fordiffusers. this experiment For thiscough experiment was investigated cough was as investigated it yields the ashighest it yieldsnumber the highest of droplets. number of droplets.
HVAC&R Research. http://dx.doi.org/10.1080/10789669.2013.842447
Legend Legend Airflow patterns in indoor environment are generated by :
2m; 6 ACH
3m; 6 ACH 4m; 6 ACH
3m; 6 ACH 4m; 6 ACH
1m; 12 ACH 1m; 12 ACH 0.000016
2m; 12 ACH 2m; 12 ACH
0.000014
3m; 12 ACH 3m; 12 ACH 4m; 12 ACH 4m; 12 ACH
0.000012
exhaust grille exhaust grille
A field env that suppl total ventil diffusers. F
- Human movements.
B
B
Ceiling mounted Ceiling mounted supply diffuser 1m;supply 6 ACH diffuser
- Door movements.
2m; 6 ACH
1M (3')
0.00001
(3') (9')Line 4M1(12') 3M (9') 4M (12') Line1M 1 3M 0.000016
1m (3’)
2m 1m 3m (6’) (3’)(9’)
A
A
0.000008 0.000006
3m; 6 ACH 4m; 6 ACH
0.000018
2m4m 3m (6’)(12’) (9’)
0.000014
W = 8m (26.3’)
2m; 6 ACH
Airflow patterns generated by ventilation Ceiling mounted Ceiling mounted systems can be controlled
- The ventilaton system.
Volume of droplets [ml/L]
1m; 6 ACH
W = 8m (26.3’)
0.000018
1m; 6 ACH
W = 8m (26.3’)
- Door movements. - Door movements.
Volume of droplets [ml/L]
1m; 12 ACH 2m; 12 ACH
4m (12’)
3m; 12 ACH 4m; 12 ACH
0.000012 0.00001 0.000008 0.000006
0.000004
0.000004
0.000002
0.000002
15-20
10-15
8-10
6-8
4-6
3.2-4
2-3.2
1.6-2
1.3-1.6
1-1.3
Manikin
0.8-1
Manikin
15-20
10-15
8-10 15-20
6-8 10-15
4-6 8-10
3.2-4 6-8
2-3.2 4-6
1.6-2 3.2-4
1.3-1.6 2-3.2
1-1.3 1.6-2
0.8-1 1.3-1.6
1-1.3
L = 11.12 m (36.5’) L = 11.12 m (36.5’) 0.8-1
Volume of droplets [ml/L]
This study indicated that local air flow pattern is an important factor in influencing dissemination of cough droplets and consequential exposure. In addition to air change rate, which can’t be assumed as the sole factor 0.000018 of air delivery system performance to reduce exposure to 0.000016 airborne infectious particles. By conducting experiments 0.000014 in the field environmental chamber (FEC) at the National University of Singapore. This study indicated 0.000012 that increase of supply flow rate may cause increase 0.00001 in the airborne infection risk transmission for several position of the cough source and the exposed person in 0.000008 relation to the supply and return air grills. For airflow 0.000006 field investigation the study utilized particle image 0.000004 velocimetry (PIV), in simulated office environment with 0.000002 ceiling mounted diffusers.
Sampling tubes Sampling were placed tubesinwere the placed middle in of the middle of Manikin the FEC 1.2 mthe from FECthe 1.2 floor m from the floor
Manikin
- Human movements. - Human movements.
Initial droplet diameter [μm]
Initial droplet Initial diameter droplet [μm]diameter [μm]
Figure: Droplet size resolved volume exposure profiles at 6 and 12 ACH
Sampling tubes were placed the placed middle in of the the middle FEC 1.2ofmthe FEC 1.2 m Sampling tubesinwere from the floor from the floor
Figure: Droplet Figure: size resolved Droplet volume size resolved exposure volume profiles exposure at 6 and profiles 12 ACH at 6 and 12 ACH
Volume of droplets in the breathing zone [ml] ACH 12
-1
-1
Air leakage rate Airwas leakage measured rate was to ebe measured 0.7 h to when ebe 0.7 h when -1 -1 the total air change the total rateairofchange 6 h was rateapplied of 6 h was applied
Leak
Leak
Average air temperature Average airintemperature the FEC was in23 theCFEC ± 0.5C was 23 C ± 0.5C (73.4F ± 0.9F). (73.4F ± 0.9F). MeasurementsMeasurements during experiment during show experiment that average show that average humidity was humidity 52% ± 5%. was 52% ± 5%. AHU control system AHU control was setsystem to maintain was setrelative to maintain relative humidity below humidity 70%. below 70%. The experimental The setup experimental resemled setup an office resemled an office environment with environment two occupants with two facing occupants facing eachother. eachother.
AUG 10, 2020
0.00E+00 1.00E+06
1.00E+06 2.00E+06
2.00E+06 3.00E+06
3.00E+06 4.00E+06
4.00E+06 5.00E+06
5.00E+06 6.00E+06
Leak
6.00E+06
ACH 6
1m
2m
3m
4m
Distance between cough source & BTM (Thermal breathing manikin)
Leak ACH 6
0.00E+00
to when ebe-11.3
Air leakage h when the total air change the total rateairofchange 12 h rate was of applied 12 h was applied
Leak ACH 6
-11.3 h rate Airwas leakage measured rate was to ebe measured -1 -1
Distance between cough source & BTM (Thermal breathing manikin)
ACH 12
1m
-1
Air leakage rate was measured to ebe 0.7 h when the total air change rate of 6 h-1 was applied
Leak
8.5
’H
8.5
’ HAverage air temperature in the FEC was 23 C ± 0.5C (73.4F ± 0.9F).
2m Measurements during experiment show that average humidity was 52% ± 5%. AHU control system was set to maintain relative humidity below 70%.
3m
3’
The experimental setup resemled an office environment with two occupants facing eachother.
36
4m
.5’
L
36
.5’
L
6’
Distance between cough source & BTM (Thermal breathing manikin)
Air leakage rate was measured to ebe 1.3 h-1 when the total air change rate of 12 h-1 was applied
Volume of droplets Volume in of thedroplets breathing in the zone breathing [ml] zone [ml] ACH 12
0.00E+00
2.00E+06
3.00E+06
4.00E+06
5.00E+06
6.00E+06
1m
8.5
’H
2m
3m
3’4m
9’
1.00E+06
6’
9’ 12Figure: Volume1of2droplets in the breathing zone integrated for all droplets sizes at various distances between cough source and BTM and two supply air flow rates. ’ ’ .3’
26
W
.3’
26
W
Figure: Volume Figure: of droplets Volume in of thedroplets breathing in the zone breathing integrated zone for integrated all dropletsfor sizes all droplets at sizes at various distances various between distances cough between sourcecough and BTM source andand twoBTM supply and airtwo flowsupply rates. air flow rates.
MANUAL OF PHYSICAL DISTANCING
P. 33
ANALYSIS OF GRADIENT OF EXPOSURE Air filter efficiency
Mechanical filters can be utilized to capture airborne particles in the air distribution system. They are typically rated based on the efficiency of the filter in capturing airborne particles. However, they require periodic maintenance or replacement.
Source 1: EPA. United States Environmental Protection Agency
MERVs (Minumum Efficiency Reporting Values) : filter’s ability to capture larger particles between 0.3 and 10 microns
https://www.epa.gov/indoor-air-quality-iaq/what-merv-rating-1 Source 2: ASHRAE. The American Society of Heating, Refrigerating and Air Conditioning Engineers.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
https://ashrae.iwrapper.com/ViewOnline/Standard_52.2-2017
Mechanical air filters can be utilized as one of the means to control indoor air quality (IAQ). Filter rating varies in accordance with their ability to capture particles, among those rating systems developed by ASHRAE is MERVs ( Minimum Efficiency Reporting Values rating), the higher the MERV value the more efficient the filter at capturing particles. Another type of filter that is highly efficient and typically used in hospital environments is HEPA filter which stands for “ High Efficiency Particulate Air”. This filter can remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns. Mechanical air filters require periodic maintenance for cleaning or replacement to be effective.
1-4 6 8
MERVs
3-10 µm 3-10 µm
10 12
1-3 µm 3-10 µm
16
49.9%
3-10 µm 1-3 µm 3-10 µm
14
less than 20%
84.9% 50% -64.9% 85% or greater 80% -89.9% 90% or greater 90% or greater
1-3 µm 75%-84%
0.3-1µm 1-3 µm 0.3-1µm
75 or greater
HEPA (High efficiency particulate air): filter, this type can theoretically remove at least 99.97% of dust, polen, mold, bacteria, and any airborne particles with size of 0.3 microns. 0%
HEPA
Particle size range
10%
20%
30%
0.3 µm
40%
50%
60%
70%
80%
90%
100%
99.97%
3-10 µm
1-3 µm
0.3-1 µm 0.3 µm
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 34
ANALYSIS OF GRADIENT OF EXPOSURE Air filter efficiency
The higher the filter rating the more efficient is the filter at capturing contaminants based on ASHRAE guidelines. However, for optimum application filters should be chosen based on the desired performance.
Source 1: ASHRAE. The American Society of Heating, Refrigerating and Air Conditioning Engineers
MERVs (Minumum Efficiency Reporting Values) : Applications guidelines per ASHRAE
https://ashrae.iwrapper.com/ViewOnline/Standard_52.2-2017 1
This illustrates application guidelines in relation to filter rating as per ASHRAE recommendation for typical applications. This only indicates the typical use which may not correspond to the optimum usage or specific configuration of the building itself.
>10µm particle size
Minumum filtration Residential window air conditioners
2 3 4
5
3-10µm particle size
Commercial buildings
Better residential
Industrial workplaces
Better commercial buildings
Superior residential
Hospital laboratories
Hospital inpatient care
General surgery
Smoking lounges
Paint booth inlet air
6 7 8
MERVs 9
1-3µm particle size
10 11 12
13
0.3-1µm particle size
Superior commercial buildings
14 15 16
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MANUAL OF PHYSICAL DISTANCING
P. 35
ANALYSIS OF GRADIENT EXPOSURE ASHRAE Position On Infectious Aerosols ASHRAE Board of Directors (April 14, 2020). ASHRAE Position Document on Infectious Aerosols. ASHRAE. https://www.ashrae.org/file%20library/about/position%20 documents/pd_infectiousaerosols_2020.pdf
This report by ASHREA evaluates the role of air movement on the aerosol particles within indoor spaces.
One of the major transmission methods for COVID-19 is through aerosol particles that can remain in circulating air for up to 41hours. HVAC systems play a role in the movement of virus aerosol particles. Directional airflow can create clean-to-dirty flow patterns and move infectious aerosols to be captured or exhausted.
Unconditioned Spaces
Existing HVAC Systems
Recommended Measures for Conditioned Space
100 90 80
> 60% Humidity: Hospitable for Virus
Humidity (%)
70 60 50
40-60% Humidity: Unfavorable for Virus
40 30 20
< 40% Humidity: Impairs mucus membrane
10 0
While many buildings are fully or partially naturally ventilated, a complete reliance on passive strategies create different risks and benefits. Generally speaking, designs that achieve higher ventilation rates will reduce risk. Unconditioned spaces are more susceptible to outdoor air quality, including the level of allergens and pollutants, varying temperature and humidity conditions, and flying insects. These types of spaces can cause thermal stress that may be directly life threatening and may lower resistance to infection. For this reason, the disabling of heating, ventilation, or air conditioning is not advised.
AUG 10, 2020
Though they contribute to the circulation of aerosol particles, HVAC systems cannot singularly control all air flow and prevent transmission. Filtration will not remove all risk of transmission as ambient circulation of particles does not guarantee the passage of all air through the mechanical system. Additionally, the controlled humidity of indoor air directly affects the endurance of the virus. A relative humidity of 40%60% is most unfavorable for the virus. However, a relative humidity below 40% impairs the mucus membrane, increasing the risk of transmission.
MANUAL OF PHYSICAL DISTANCING
The following are strategies that should be considered: • Enhanced filtration (higher minimum efficiency reporting value [MERV] filters over code minimums in occupant-dense and/or higherrisk spaces) • Upper-room UVGI (with possible in-room fans) as a supplement to supply airflow • Local exhaust ventilation for source control • Portable, free-standing high-efficiency particulate air (HEPA) filters • Temperature and humidity control
P. 36
ANALYSIS OF GRADIENT OF EXPOSURE Sterilization method from UVC light
Different types of ultraviolet light have the ability to kill airborne viruses, but have different impacts on humans. In this study far UVC light, does not harm human cells or tissue like UV light, inactivated 99.9% of aerosolized virus particles. UVC
Source 1: Buonanno Manuela, Welch David, Shuryak Igor, Brenner David J (April 27, 2020 ). Far-UVC light efficiently and safely inactivates airborne human coronaviruses . https://www.researchsquare.com/article/rs-25728/v1. Source 2: Cantor Carla (April 21, 2020 ). Could a New Ultraviolet Technology Fight the Spread of Coronavirus?. Columbia news
https://news.columbia.edu/ultraviolet-technology-virus-covid-19-UV-light
While ultraviolet light UV is known to be effective in inactivating a range of pathogens it is harmful to human tissues and therefore limited in it’s utility for sanitizing occupied spaces. This study examines the use of far UVC light, a specific wavelength of UV radiation that does not affect human cells and could be employed in inhabited areas without risks to occupants. The study found that low doses of far UVC light inactivated 99.9% of aerosolized particles of two related human corona virus species in 25 minutes.
100 100
UVB
UVC UVC UVC UVC
100 100 100
280 UVB UVB 280 UVB
Ultraviolet
UVA
UVB
Ultraviolet 280 280 280 Ultraviolet Ultraviolet Ultraviolet
315 315
VISIBLE
UVA
400
UVA UVA UVA
500
400
315 315 315
500
400 400 400
VISIBLE
600
VISIBLE VISIBLE VISIBLE
500 500 500
700
600
750 nm
700
600 600 600
750 nm
700 700 700
750 750 nm nm 750 nm
Germicidal Ultraviolet Light (UV) typically at 254 nm Health hazard for human cells, tissues and eyes
Kills airborne pathogens
Used as a method of sterilization for hospitals, airplanes, offices, factories
Prices range depending on usage and effectiveness
Without harm to exposed human cells or tissue
Kills airborne pathogens
Far UVC lamps are currently in production, However, it is scaling up for mass production and approval from the food and drug administration and environmental protection agency is pending
Prices will range at between $ 500 $ 1000 per lamp, once they are mass produced the price would be lower as anticipated in the study
Far UVC light (207-222 nm)
2
Recommended exposure limit for public areas at (3 mJ/cm /hour) Virus strain tested
Far UVC light
Far UVC dose
Virus strain tested HCoV-229E ( Alpha) * Virus 90% strain tested tested Virus Inactivation Virus strain HCoV-229E Alpha) * Virus(Inactivation Virus 99% strain tested 99.9% Inactivation 90% Virus Inactivation HCoV-229E (Virus Alpha) * HCoV-229E ( Alpha) * 99% Virus Inactivation 90%99.9% VirusVirus Inactivation HCoV-229E (Inactivation Alpha) * 90% Virus Inactivation 99% Virus 99% Virus Inactivation Inactivation 90%HCoV-OC43 ( Beta)* 99.9% Virus Inactivation 99.9% Virus Virus Inactivation Inactivation 99% 90% Virus Inactivation 99.9% VirusVirus Inactivation HCoV-OC43 (Inactivation Beta)* 99% 99.9% Inactivation 90% Virus Virus Inactivation HCoV-OC43 ( Beta)* Beta)* HCoV-OC43 ( 99% Virus Inactivation 90% Virus HCoV-OC43 (Inactivation Beta)* 90%99.9% VirusVirus Inactivation Inactivation 99% Virus 99% Virus Inactivation A ( H1N1) 90%Influenza Virus Inactivation Inactivation 99.9% Virus Inactivation 99.9% Virus Virus Inactivation Inactivation 99% 90% Virus Inactivation 99.9% VirusVirus Inactivation Influenza A ( Inactivation H1N1) 99% 99.9% Inactivation 90% A Virus Inactivation Influenza A ((Virus H1N1) Influenza H1N1) 99% Virus Inactivation 90% Virus Inactivation Influenza A (Virus H1N1) 90%99.9% Virus Inactivation Inactivation 99% 99% Virus Inactivation Inactivation 90% Virus 99.9% Virus Inactivation 99.9% Virus Virus Inactivation Inactivation 99% 99.9% Virus Inactivation
0.56
1.1
0.56 0.56 0.56 0.56 0.39
1.7
1.1 1.1 1.1
1.7 1.7 1.7
0.78
0.39 0.39 0.39 0.39
1.7
1.1
1.2
0.78 0.78 0.78 0.78
1.2 1.2 1.2 1.2
1.3
2.6
1.3 1.3 1.3 1.3
3.8
2.6 2.6 2.6 2.6
3.8 3.8 3.8 3.8
HCoV-229E ( Alpha)* : A species of corona virus that infects humans and bats HCoV-OC43 ( Beta)* : A species of corona virus that infects human and cattle
25 min 25 min 25 25 min min 25 min
99.9 % 99.9 %
AUG 10, 2020
99.9 99.9 % % 99.9 %
The study suggests that continuous exposure in public locations at the currently recommended exposure limit at ( 3 mJ/cm2/hour), would take about 25 minutes for 99.9% viral inactivation, based on the results of beta corona virus. SARS-Cov2: Covid 19 corona virus species. The study didn’t test how far UVC light affects COVID19. However, The study expected comparable “inactivation efficiency” against COVID 19 Far UVC exposure based on the assumption of the similarity of genomic size across human corona viruses, which is a key factor of radiation sensitivity. According to the study far UVC light can inactivate 99.9% of aerosolized alpha and beta corona virus using low doses of far UVC 1.7 and 1.2 ( mJ/cm2/hour) respectively
MANUAL OF PHYSICAL DISTANCING
P. 37
ANALYSIS OF GRADIENT OF EXPOSURE Sterilization method utilizing ultraviolet germicidal lights Source 1: CDC Enviromental control for tuberculosis: Basic Upper Room ultraviolet Germicidal irradiation Guidelines for Healthcare Settings https://www.cdc.gov/niosh/docs/2009-105/pdfs/2009-105.pdf?id=10.26616/NIOSHPUB2009105
100
CDC and ASHRAE have explored how UV light can be used to disinfect spaces through different ways of locating the UV source within buildings. The CDC and ASHRAE reports were not done specifically on Covid-19, but address a wide range of biological contaminants, and the role that UV light can play in interrupting the transmission pathogens. UV approaches are different depending on if the contaminant is airborne or a surface contaminant. Airborne contaminants may be addressed in the mechanical system, whereas surface contaminants require light to be brought into the space. Human health risk by UV light is a significant consideration.
280
UVA
VISIBLE
315
400
500
600
700
750 nm
Ultraviolet
Source 2: ASHRAE 2019 HVAC APPLICATIONS. CH 62 Ultraviolet air and surface treatment https://www.ashrae.org/file%2 library/technical%20resources/covid19/i-p_a19_ch62_uvairandsurfacetreatment.pdf
UVB
UVC
There are different methods to use UV light inside buildings, from integration within mechanical ducts and systems, to stand alone portable room disinfection units. These systems efficacy is dependent on duration, light intensity among other factors, which impacts costs and viability of this approach.
UVGI applications and systems Typically combined UVC with conventional air quality control methods, including dilution, ventilation and particulate filtration. The ability of UVC to inactivate bio aerosols is a function of dose. Dose is the length of time of exposure multiplied by the irradiance measured ÎźW/cm2 ( Ch 62.5 Source 2). Key difference between surface decontamination and airborne inactivation is exposure time.
In duct surface disinfection
Induct air disinfection
UVC can be applied to HVAC systems, typically in AHU
In duct systems are designed for an air velocity around 500 ft/ min at this velocity, an irradience zone 8â&#x20AC;&#x2122; in length achieves a 1 s exposure (source 2). Virus strain tested HCoV-229E ( Alpha) * 90% Virus Inactivation 99% Virus Inactivation 99.9% Virus Inactivation
Upper room disinfection The system interrupts the transmission of airborne pathogens within indoor environment. Effective in areas with no or minimal ventilation (source 2).
HCoV-OC43 ( Beta)* 90% Virus Inactivation 99% Virus Inactivation 99.9% Virus Inactivation
0.56
0.39
Influenza A ( H1N1) 90% Virus Inactivation 99% Virus Inactivation 99.9% Virus Inactivation
1.1
0.78
1.7
1.2
In room surface disinfection Could be portable in room disinfec1.3 tion device as shown above or standalone
2.6
3.8
25 min
MANUAL OF PHYSICAL DISTANCING
AUG 10, 2020 99.9 %
P. 38
ANALYSIS OF GRADIENT OF EXPOSURE The role of natural ventilation airflow in high rise residential buildings Source 1: N.P. Gao, J.L. Niu, M. Perino, P. Heiselberg (November 19, 2007 ). The airborne transmission of infection between flats in high-rise residential buildings: Tracer gas simulation . https://doi.org/10.1016/j.buildenv.2007.10.023
a
b
c
2 3
There are two major forms of natural ventilation:
2
3
1- Single sided
This study evaluated the airborne transmission in indoor settings, in relation to natural ventilation through open windows across apartments in high rise residential buildings caused by buoyancy effects. This study done in Hong Kong confirmed that exhaust contaminated air from the window of the lower floor apartment re-enters into adjacent upper floor units through both qualitative and quantitative means. Contaminants generated in the lower floor are generally lower in the adjacent upper floor by two folds. In the case of single side window opening conditions with the wind blowing in perpendicular direction, the study found that this may strengthen or lower the upward cascading effect, depending on the wind speed.
Building design and articulation could impact the natural ventilation air flow and the re-entry of air from lower floors into immediate floors above that is created due to the cascade effect.
4
Typically generate low ventilation rate Prevalent model in dense urban environments where there may be one opening in the external facade. In this configuration, wind turbulence and temperature differences between indoor and outdoor areas are the main driving force.
2 2 3
3
2 3 3 5
2
4 5
6 9
4
Flo
2
2
9
8
or 4
9 8
6
4
2
3 9
4
6 3
5
6 5
8 7
5
4
5
7
3 4
8
6
2- Cross flow Generally promotes airflow through space via openings on various space facades. Room immediately upstairs could contain up to 7% of the exhaust air from the lower floor.
Flo
Tracer gas CO2, which is generated in the middle of the 2nd floor at a rate of 8 mg/s
or 3
3’-
2
W=
2’-
6”
3 6
rd
or 1
10%
20%
7’
-1
0”
(2
Mean risk of infection 0.1 m/s (Second floor) % 0.5 m/s 1.0 m/s 2.0 m/s
.4
L=
m
’-2
10
30%
40%
50%
30% 28% 29% 31%
4
9
5 5
7
9
8
Distribution of mass fraction (kg/kg) of tracer gas CO2 which is generated in the middle of the second floor at a rate of 8 mg/s. Velocity inlet
Symmetry
Pressure outlet
46%
Symmetry
2%
0.1 m/s
16 H
3.4% 3.5% 6.6% 1.7% 7.5 %
0.5 m/s 1.0 m/s 2.0 m/s 4.0 m/s
)
8 6
)
4.0 m/s
Re-entry ratio %
2
3
1m
. ’ (3
5
6 7
2 5
Flo
=
5
7
wa
W
4.0 m/s
Level CO2 9 2.99E -04 8 1.75E -04 7 1.50E -04 6 1.25E -04 5 1.00E -04 4 7.50E -05 3 5.00E -05 2 2.50E -05 1 0.00E +00
”
W in
To estimate the ventilation rate through opening, the study utilized the tracer gas concentration decay calculation (page 1810), by monitoring the transient evolution of the volume average concentration indoors.
Mean risk of infection 0.1 m/s (Third floor) % 0.5 m/s 1.0 m/s 2.0 m/s
e
11
Flo
or 2 2 ’-7 ”
Buoyancy effect* is the force exerted in an object that that is completely or partially submerged in a fluid (gas or liquid) at rest is acted upon by an upward, or buoyant, force, the magnitude of which is equal to the weight of the fluid displaced by the body (source 2).
d
9.6 % 10.9% 16.3% 3.5 %
* Source 2: Brittanica. Archimedes’ principle. https://www.britannica.com/science/Archimedes-principle#ref1252883 AUG 10, 2020
Mean risk of infection from Wells-Riley equation and re entry ration in various cases MANUAL OF PHYSICAL DISTANCING
16 H
36 H P. 39
ANALYSIS OF GRADIENT OF EXPOSURE The role of natural ventilation airflow in high rise residential buildings
The study examined the implication of passive air flow and natural ventilation between floors, determining that there is a notable amount of air that moves from lower floors to upper floors through windows.
Source 1: J. Niu T. C. W. Tung (December 18, 2007 ). On-site quantification of re-entry ratio of ventilation exhausts in multi-family residential buildings and implications https://onlinelibrary.wiley.com/doi/full/10.1111/j.16000668.2007.00500.x
Building Building
Mean wind Mean wind(m/s)/ speed speed (m/s)/ temperature temperature (C) (C)
Wall
Wall
Door Door
Max wind Maxspeed wind (m/s)/ speed (m/s)/ temperature temperature (C) (C)
Min wind Minspeed wind (m/s)/ speed (m/s)/ temperature temperature (C) (C)
6.5/31.8 6.5/31.8 7.7/27.1 7.7/27.1 5.9/27.0 5.9/27.0
0.1/24.0 0.1/24.0 0.1/18.4 0.1/18.4 0.1/18.6 0.1/18.6
0.06 0.06
Exhaust air re entry ratio K
Meshed air Meshed air window window
Exhaust air re entry ratio K
Air slits Air window Air slits Air window Exhaust fan Exhaust fan
Period Period (year of 2003) (year of 2003)
Wing Shui House May 7 to May 14 2.7/27.0 Wing Shui House May 7 to May 14 2.7/27.0 Hing Tung House April1 to April 9 2.9/22.2 Hing Tung House April1 to April 9 2.9/22.2 Koway court March 25 to April1 2.5/21.9 Koway court March 25 to April1 2.5/21.9
8’ (2.4m)
1-Wing Shui House : 15 storey highrise with communal ground 1-Wing Shui House : 15 storey highrise with communal ground floor. There are 40 rooms on each floor, and floor to ceiling floor. There are 40 rooms on each floor, and floor to ceiling height is 8’ (2.4m). height is 8’ (2.4m). 8’ (2.4m)
0.05 0.05 0.04 0.04 0.03 0.03 0.02 0.02 0.01 0.01 0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Upper room (V2)
2-Hing Tung House : 25 storey block, # of rooms per floor 2-Hing Tung House : 25 storey block, # of rooms per floor is 26 except that the top floor has 22 rooms. The height is 26 except that the top floor has 22 rooms. The height of the room is 8’ (2.4m). cross ventilation was utilized of the room is 8’ (2.4m). cross ventilation was utilized
Door Door
P-5,C5 P-5,C5 P-6,C6 P-6,C6
P-4,C4 P-4,C4 Mixing Mixing zone zone
Infiltration Infiltration Lower room (V1)
Upper room (V2)
Wind speed (m/s) Wind speed (m/s) Variation of the re-entry ratio k with the monitored local Variation of the re-entry ratio k with the monitored local wind speed. wind speed.
Lower room (V1)
This study evaluated the role of building design characteristics in relation to natural ventilation in the transmission of SARS. By reviewing the architectural and ventilation design of high residential buildings with case clusters in Hong Kong. In order to identify airflow paths the study utilized on site experiment and numerical simulation. The study incorporated dual tracer gases of CO2 and SF6 simultaneously in order to determine the amount of exhaust air that comes out of the lower floor window opening and re-enters the upper floor window opening due to the cascade effect. This study found that room air could contain up to 7% of the exhaust air from the lower floor under certain environmental conditions during low wind conditions with a combination of indoor-outdoor temperature difference. The results indicated that in high rise buildings, windows flush with a flat facade can be a major route for vertical spread of contaminated air. This study suggested that having external ledges above windows incorporated into the architectural design of facades may mitigate re entry into the upper floor and increase dispersion.
Summary of meteorology information from the nearby meteorology stations of three buildings Summary of meteorology information from the nearby meteorology stations of three buildings
P-2,C2 P-2,C2 P-3,C3 P-3,C3
P-1,C1 P-1,C1
Door Door Infiltration Infiltration
3-Koway court : 22 storey high rise buildings on a podium, the 3-Koway court : 22 storey high rise buildings on a podium, the room height is about 2.65m room height is about 2.65m
AUG 10, 2020
Floor plan of the sampled residential units, and two rooms in Floor plan of the sampled residential units, and two rooms in adjacent lower and upper floors were used adjacent lower and upper floors were used
MANUAL OF PHYSICAL DISTANCING
SF6 dosing point SF6 dosing point Tracer gas dosing and sampling points in the two adjacent Tracer gas dosing and sampling points in the two adjacent floors upstairs and downstairs. floors upstairs and downstairs.
P. 40
ANALYSIS OF GRADIENT OF EXPOSURE Spatial distancing - spatial planning AIA, (May 6, 2020) Re-occupancy Assessment Tool V1.0.
The AIA has issued a tool to aid in re-occupancy. This tool uses a set of best-practices to address the challenges of re-occupying indoor space.
Fig1: Source 1. Applying the hierarchy of controls for COVID 19 (adapted from NIOSH (National Institute for Occupational Safety and Health)), adopted by CDC, AIA Applying the hierarchy of controls for COVID -19 Applying the hierarchy of controls for COVID -19
The American Institute of Architects (AIA) put out a re-occupancy assessment tool to help facility managers and architects assess risk and determine ways to adjust to the impact of Covid-19. This tool combines the CDC guidelines while identifying the spatial separation required for physical distancing. The AIA encourages planners and architects to use a 6 foot radius as a planning unit as it accommodates someone moving between people.
Optimum scenario: Dynamic movement and navigation 6'-0"
6'-0"
6'-0"
6'-0"
Most effective Elimination
Social isolation
Substitution
(not applicable)
Engineering controls 6'-0"
Administrative controls
6'-0"
Least effective
6'-0"
6'-0"
PPE
Ventilation, physical barriers
6'-0"
Work from home, stagger schedules, hand hygiene
6'-0"
A six-foot 6'-0" radius allows for people to move through and navigate a space at the tangent of the physical distancing circle formed by the six-foot radius. That allows for the dynamic movement of people in a space. 6'-0"
6'-0"
6'-0"
Masks, resporators, gloves
AIA Evaluation
Limited scenario: Static in terms of physical distancing space
Area per occupant = 113.097 sqft The area of a 6-foot radius circle is 113.097 square feet (Pi x 6-foot radius squared).
6'-0"
Based on the common measure recommended by CDC which is to to keep 6’ between the individual and others
3'-0"
This principle can be used as a guide to identify the building and fire code occupancies, and their respective occupant levels, that would be affected by using the CDC-recommended physical distancing of six feet. This evaluation doesn’t account for the implementation of architectural and engineering controls nor the use of PPE.
6'-0"
3'-0"
6'-0" 6'-0"
If the 6'-0" physical distance between each person was exactly six feet, then the physical distancing would be violated when people move through the space. Applicable 3'-0" when people are standing in a line, or when people are seated 6’ apart. Linear and doesn’t account for movement through space. 3'-0"
6'-0"
6'-0" 6'-0"
AIA Nominal area per occupant=100 SF To simplify the calculations and for 6'-0" purposes a nominal area of 100 square feet per person is used rather than the area of a 6-foot radius 6'-0" circle of 113.097 square feet, as a 6'-0" comparison for the stated allowable occupancy levels in the building code.
6'-0"
6'-0"
Utlilizing the optimum scenario arrangement that allows for users movement and access
6'-0" 6'-0" 6'-0"
6'-0" 6'-0" 3'-0" 3'-0" 3'-0" AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
3'-0"
P. 41
ANALYSIS OF GRADIENT OF EXPOSURE Spatial distancing - spatial planning https://www.aia.org/resources/6292441-re-occupancy-assessment-tool
The American Institute of Architects (AIA) tool for re-occupying spaces provides a summary of the coderequired areas per person in a given type of functional space. The re-occupany tool recommends using 100 square feet per person as a rough estimate to meet social distancing guidelines. The 100 square feet per person is a slight reduction from the 113.097 square feet per person that is the area of a circle with a radius of 6 feet. This slight reduction allows easier calculations and is a recognition of the dynamic nature of the 6 foot social distancing guideline to mitigate risk. This measure of physical distancing has significant impacts on building use occupancy calculations which under contemporary building codes allow for fewer square feet per person. The AIA notes, however, that their tool cannot be just used to determine number of people in a space, but must be done in conjunction with ensuring that these occupants are able to maintain the social distancing of 6 feet in any space. In short, occupancy reductions must be aligned while maintaining social distancing protocols.
6'-0" 6'-0"
6'-0" 6'-0"
>
10'-0"
10'-0"
10'-0"
If 100 square feet is used as a nominal social distancing measure, the occupancies impacted the most are the following, with current maximum floor area allowances per occupancy (International Building Code, Table 1004.1.1, various editions). Occupancies allowing 100 gross or net square feet per occupant are not listed here since they can be considered to meet a nominal 100 square foot social distancing.
Airport: baggage claim - 20 gross
Airport: Waiting areas - 15 gross
80% reduction
85 % reduction
Assembly: gaming floors - 11 gross
Assembly with fixed seats: refer to 1004.7 of international building code
89 % reduction
Bowling centers: 7 net; check with allowances of five persons/ lane including 15 feet of runway 85% reduction AUG 10, 2020
Area = 113.097 sqft, which is larger than 10â&#x20AC;&#x2122; x10â&#x20AC;&#x2122; room.
10'-0"
10'-0"10'-0"
AIA, (May 6, 2020) Re-occupancy Assessment Tool V1.0.
10'-0"10'-0"
The AIA has issued a tool to aid in re-occupancy. This tool uses 100 square feet per person as a benchmark for future occupancy calculations, with impacts on building use.
Skating rinks, swimming pools: rink and pool- 50 gross 50 % reduction
Skating rinks, swimming pools: decks 15 gross 85 % reduction
Assembly without fixed seats: concentrated-7 net
Assembly without fixed seats: Standing space- 5 net
93 % reduction
95 % reduction
Courtrooms: 40 net
Daycare: 35 net
60 % reduction
65 % reduction
MANUAL OF PHYSICAL DISTANCING
Locker rooms: 50 gross
Education: classroom area: 20 net
50 % reduction
80 % reduction
Education: Shops, vocational rooms-50 net 50 % reduction
Assembly without fixed seats: unconcentrated (tables & chairs)-15 net 85 % reduction
Library: reading rooms-50 net
Stages and platforms: 15 net
50 % reduction
85 % reduction
Dormitories: 50 net
Mercantile: areas on other floors -60 gross
Mercantile: basement and grade floor areas-30 gross
Exercise rooms: 50 gross
50 % reduction
40 % reduction
60 % reduction
50 % reduction P. 42
The following illustrates the significant impact that different social distancing measures have on collective space. The 24'-0" R=6'-0" scenarios show a distance of 3’, 4’ and 6’ radius, respectively.
R=4'-0"
GROUP (3 PEOPLE) AREA 108 SQFT
GROUP (10 PEOPLE) AREA PER PERSON AREA 360SQFT SCENARIO 2SQFT - Radii 4’ 50.265
12'-0"
Area per person
24'-0"
32'-0"
16'-0"
GROUP (3 PEOPLE) AREA 192 SQFT
GROUP (10 PEOPLE) AREAAREA PER SCENARIO 3 -PERSON RadiiSQFT 6’ 640 113.097 SQFT Area per person 113 SF
Area per person 50 SF
6'-0"
R=3'-0"
GROUP (3 PEOPLE) R=4'-0" AREA 192 SQFT 24'-0"
GROUP (10 PEOPLE) AREA 640 SQFT
16'-0"
12'-0"
24'-0"
12'-0"
Group (3 people)
196 SF8'-0"
432 SF
16'-0"
32'-0"
24'-0"
R=6'-0" 12'-0"
18'-0"
GROUP (10 PEOPLE) AREA 640 SQFT
12'-0"
GROUP (3 PEOPLE) AREA 192 SQFT
24'-0"
12'-0"
8'-0"
GROUP (10 PEOPLE) AREA PER PERSON AREA 360 SQFT 50.265 SQFT
AREA PER PERSON 113.097 SQFT
GROUP (3 PEOPLE) AREA 432 SQFT
GROUP (10 PEOPLE) AREA 1440 SQFT
Group (10 people)
Group (10 people)
Group (10 people)
360 SF
640 SF
1440 SF
R=4'-0"
24'-0"
32'-0"
16'-0"
48'-0"
16'-0"
12'-0"
8'-0"
GROUP (10 PEOPLE) AREA 1440 SQFT
12'-0"
8'-0"
6'-0"
12'-0"
32'-0" GROUP (3 PEOPLE) AREA 432 SQFT
Group (3 people) 18'-0"
108 6'-0" SF
24'-0"
R=6'-0"
AREA PER PERSON 113.097 SQFT
16'-0"
R=4'-0"
Group (3 people)
12'-0"
16'-0"
12'-0"
GROUP (10 PEOPLE) AREA 360 SQFT AREA PER PERSON 50.265 SQFT
8'-0" 18'-0"
6'-0"
8'-0"
28 SF GROUP (3 PEOPLE) AREA 108 SQFT
GROUP (3 PEOPLE) AREA 432 SQFT 24'-0"
Group gathering
AREA PER PERSON 50.265 SQFT SCENARIO 1 - Radii 3’
GROUP (3 PEOPLE) AREA 432 SQFT
24'-0"
R=3'-0"
GROUP (10 PEOPLE) AREA640 PER PERSON AREA SQFT 113.097 SQFT
24'-0"
ANALYSIS OF GRADIENT OF EXPOSURE- DIGITAL TECHNOLOGY Spatial distancing - spatial planning
GROUP (3 PEOPLE) AREA 192 SQFT
12'-0"
GROUP (10 PEOPLE) AREA PER PERSON AREA 360 SQFT 50.265 SQFT
24'-0"
GROUP (3 PEOPLE) AREA 108 SQFT
24'-0"
AREA PER PERSON 50.265 SQFT
48'-0"
24'-0"
12'-0"
36'-0"
24'-0"
12'-0"
24'-0"
8'-0"
18'-0"
8'-0"
16'-0"
R=6'-0"
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 43
CASE STUDY: ACADEMIC CLASSROOMS
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 44
CURRENT GUIDELINES CDC Considerations - Institutes of Higher Education Source 1: CDC (May 21, 2020) . Considerations for Institutes of Higher Education
Low Low
Risk Risk
Highest Highest
Low
Risk
Highest
https://www.cdc.gov/coronavirus/2019-ncov/community/colleges-universities/considerations.html
CDC provided basic guidelines for institutes of higher education (IHE) as they open. The CDC did not provide direction on if or when IHE should open, leaving that decision to the individual institutes in coordination with local, state and federal authorities. The CDC provided Guiding Principals based on Low, More and High risk designations on IHE, but no clear mandate or directive. The Guiding Principals covered issues such as housing, personal behavior, maintenance of environments, operations, and preparation for when someone does get sick.
Remote learning only Remote learning
Low
only
Small classes, activities for Small classes, in person events, no sharing activities for in of items
person events, no sharing of items
Remote learning only
Small classes, activities for in person events, no sharing of items
Full class capacity, no
Risk
Full class capacity, no social distance with shared supply and mixing between classes
Risk Risk
Low Low
Residence halls area closed
Residence halls area closed Residence halls are
closed
Residence halls are open at fall capacity, with shared spaces open
Residence open atopen lower capacity, with capacity, Residence at lower shared spaces closed
Residence halls atwith full Residence halls are open are at fallopen capacity, shared spaces with open shared spaces open capacity,
MANUAL OF PHYSICAL DISTANCING
Highest
Highest Highest
Residence open at lower capacity, with shared spaces closed
with shared spaces closed
AUG 10, 2020
Full class capacity, social distance with shared and mixing betweenwith nosupply social distance classes shared supply and mixing between classes
P. 45
CURRENT GUIDELINES CDC Considerations- Institutes of Higher Education Source 1: CDC (May 21, 2020) . Considerations for Institutes of Higher Education
SignageSignage
Classrooms Classrooms
https://www.cdc.gov/coronavirus/2019-ncov/community/colleges-universities/considerations.html Classrooms Classrooms
The CDC guidelines for institutes of higher education are based mostly on adhering to a 6 foot social distancing rule. This dimension has impact on a range of academic space uses, from the density of desks to the use of collective spaces. These details are aligned with the mid-level of risk as outlined in the guidelines.
Signage Signage
6’
"
"
6'-06'-0 " "
6'-06'-0 " "
Recommended desk spacing
Recommended Recommendeddesk deskspacing spacing Communal spaces
6’6’
6'-0"
6'-0"
Recommended desk spacing
Please keep a minimum of 6’ between yourself and others
6'-0
6'-0
Recommended chair spacing
6'-06"'-0"
Recommended chair spacing6'-06"'-0"
Recommended Recommendedchair chairspacing spacing
Communal Communal Communalspaces spaces spaces
Please Pleasekeep keepa aminimum minimumofof6’6’between between yourself yourselfand andothers others Provide signage and physical guides such as tape on floors or
6’ apart markers such as tape on floors or Provide sidewalks signageto maintain and physical sidewalk to maintain 6’ apart
Provide Providesignage signageand andphysical physicalguides guidessuch suchasastape tapeononfloors floorsoror Gathering sidewalks sidewalkstotomaintain maintain6’6’apart apart
Physical barriers especially when 6’ can’t be maintained
Gathering Gathering Gathering
Physical barriers Physical Physicalbarriers barriers especially especially especially when 6’ when when6’6’can’t can’tbebe can’t be maintained maintained maintained
Campus dining: Change food protocol Grab and go meals, avoiding buffets and self service
Campus dining:
Campus Campusdining: dining:Change Changefood food Change food protocol protocolGrab Grab and andgogomeals, meals, avoiding avoidingbuffets buffets and andself self protocol grab and service service
go meals, avoiding buffets and self service
Closing communal spaces
Closing Closingcommunal communalspaces spaces
Limit Limitsize sizeofofgathering gathering
Closing communal spaces
AUG 10, 2020
Limit size of gathering
Limit size of gathering
MANUAL OF PHYSICAL DISTANCING
P. 46
CLASSROOM STUDY 6’-0” Social Distancing Impact on Occupancy The recommended 6’-0” minimum social distancing rules to meet Covid-19 have direct implications on the numbers of students and faculty who can meet in interior classrooms. The 6’-0” distancing guidelines means that even if students are able to gather, then class sizes will need to accommodate the reduced numbers of students, or rooms will not be usable, if this distancing guideline is implemented. 6’-0” distancing needs to reflect movement and circulation, and does not attend to aerosol risk.
6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Most classrooms try to use space efficiently which means that students are in close proximity to each other.
Medium Sized Classroom - Pre-Covid
Size: 380 square feet Occupancy: 20 people (19 sf per person)
AUG 10, 2020
Medium Sized Classroom - Social Distancing of 6’-0” Size: 380 square feet Occupancy: 8 people (49 sf per person) Utility Rate: 40% of Pre-Covid Occupancy
MANUAL OF PHYSICAL DISTANCING
P. 47
CLASSROOM STUDY Viral Risk and Limitation of Social Distancing as Only Measure The 6’-0” social distancing measurement does not encompass all issues related to classroom use and risk of exposure and transmission. Students and faculty are in the same room for extended durations. During the class period, both the droplet viral particles build up on surfaces and potentially the aerosolized particles develop in the air. After a class is over, the same issues persist in the room and transfer this potential risk to the next class.
Academic classes have long durations measured in hours. This means that there will be a build-up of potential contaminants during this time.
Virus may stay viable in aerosolized format in the air which may build up through the duration of a class. More research is needed to evaluate precise risk. Evidence comes from case-studies that reconstruct viral spread within closed rooms and rehearsal spaces.
Surfaces may accumulate droplets. Depending on the material of the surface the virus can be viable for up to 7 days.
High-touch surfaces are key areas of concern for viral accumulation and transfer.
Students and teachers move around in a classroom. The 6’-0” radius does not protect from movement or circulation overlaps. Talking and animated conversation may spread viral droplets and aerosolized particles into the room that exceed the 6’-0” social distance. guidelines.
Building-wide mechanical systems may recycle and distribute viral material within and between rooms depending on system.
Fresh air intake can dilute the aerosolized impact, and should be maximized where possible.
Medium Sized Classroom - Viral Risk During Class Size: 380 square feet Occupancy: 8 people (49 sf per person)
AUG 10, 2020
Medium Sized Classroom - Residual Contamination Size: 380 square feet Occupancy: 8 people (49 sf per person)
MANUAL OF PHYSICAL DISTANCING
P. 48
CLASSROOM STUDY 6’-0” Social Distancing Impact on Occupancy The following demonstrate the occupancy reduction as a consequence of adhering to a 6’-0” minimum social distancing guideline.
Large Sized Classroom - Pre-Covid Small Sized Classroom - Pre-Covid
Size: 290 square feet Occupancy: 16 people (18 sf per person)
Small Sized Classroom - Social Distancing of 6’-0” Size: 290 square feet Occupancy: 6 people (41 sf per person) Utility Rate: 44% of Pre-Covid Occupancy AUG 10, 2020
6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Size: 725 square feet Occupancy: 28-38 people (26 sf per person)
6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Large Sized Classroom - Social Distancing of 6’-0” Size: 725 square feet Occupancy: 11 people (66 sf per person) Utility Rate: 39% of Pre-Covid Occupancy MANUAL OF PHYSICAL DISTANCING
P. 49
CLASSROOM STUDY Alternative Social Distancing Arrangements The following demonstrate a range of classroom arrangements that follow the 6’-0” social distancing guidelines. Each demonstrate a significant reduction in occupancy.
Two rows of students may create difficult arrangements for holding class discussions.
Large Sized Classroom - Seminar Table with Extra Row Size: 725 square feet Occupancy: 14 people (52 sf per person) Utility Rate: 50% of Pre-Covid Occupancy
Large Sized Classroom - Central Seminar Table Size: 725 square feet Occupancy: 11 people (66 sf per person) Utility Rate: 39% of Pre-Covid Occupancy
Circulation around each seat is a challenge as it would break the distancing rule.
6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Large Sized Classroom - Lecture Format
Size: 725 square feet Occupancy: 13 people (56 sf per person) Utility Rate: 46% of Pre-Covid Occupancy AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 50
CLASSROOM STUDY 4’-0” and 8’-0” Social Distancing Arrangements Given human movement, and mask errors, 6’-0” may not be sufficient. 8’-0” would be a safer amount to use, especially in tight interior spaces where air circulation is limited compared to outside areas.
The 6’-0” social distancing dimension is a rough approximation intended to mitigate risk. This dimension varies by country, with 2 meters being used widely as well. These diagram examine the impact of different social dimensioning sizes on occupancy, and raise the issue as to the relationship between safety and rules of protection or risk management. 4’-0” is not a recommended distance, and would only be possible with significant additional PPE requirments and strict adherence. Mask and other PPE are prone to mis-use and failure, requiring the minimum 6’-0” distancing as added level of safety.
With 4’-0” spacing, the number of occupants comes closer to precovid amounts.
Medium Sized Classroom - 4’-0” Social Distancing Size: 380 square feet Occupancy: 13 people (30 sf per person) Utility Rate: 65% of Pre-Covid Occupancy
AUG 10, 2020
Medium Sized Classroom - 8’-0” Social Distancing Size: 380 square feet Occupancy: 13 people (78 sf per person) Utility Rate: 25% of Pre-Covid Occupancy
MANUAL OF PHYSICAL DISTANCING
P. 51
CLASSROOM STUDY
22'-0"
22'-0"
AUG 10, 2020
27'-0"
SIZE: 540 sf
POST-COVID CAPACITY: 6’ Distancing, 27'-0"Existing furniture: 16 Maximum (46 sf/person)
15'-0"
SIZE: 375 sf POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 8 Maximum (47 sf/person)
MANUAL OF PHYSICAL DISTANCING
25'-0"
18'-0"
25'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 14 Maximum (51 sf/person)
27'-0"
40'-0"
18'-0"
20'-0"
25'-0"
40'-0"
40'-0"
SIZE: 720 sf
18'-0"
15'-0"
18'-0"
20'-0"
20'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 11 Maximum (49 sf/person)
15'-0"
12'-0"
12'-0"
SIZE: 216 sf
27'-0"
12'-0"
18'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 6 Maximum (36 sf/person)
23'-0"
27'-0"
15'-0"
15'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 8 Maximum (43 sf/person)
15'-0"
SIZE: 345 sf
27'-0"
SIZE: 729 sf 27'-0"
22'-0"
22'-0"
18'-0"
18'-0"
18'-0"
23'-0"
34'-0"
22'-0"
27'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 10 Maximum (48 sf/person)
34'-0"
21'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 14 Maximum (51 sf/person)
SIZE: 484 sf
23'-0"
34'-0"
SIZE: 714 sf
21'-0"
14'-0"
22'-0"
18'-0"
28'-0"
27'-0"
18'-0"
28'-0"
21'-0"
28'-0"
POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 9 Maximum (44 sf/person)
SIZE: 324 sf POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 8 Maximum (40.5 sf/person)
21'-0"
14'-0"
SIZE: 392 sf
Large Seminar Room (550-800 sf)
18'-0"
18'-0"
21'-0"
14'-0"
14'-0"
14'-0"
21'-0"
SIZE: 294 sf POST-COVID CAPACITY: 6’ Distancing, Existing furniture: 7 Maximum (42 sf/person)
Medium Seminar Room (350-550 sf)
14'-0"
Small Seminar Room (200-350 sf)
P. 52
CLASSROOM STUDY Open Studio Spaces Depending on the amount of space provided to a student, social distancing may be possible to establish in studios. However, the major challenge of creative studios and offices is the dynamic nature of the work, the movement of people, and the large durations of time where the virus can accumulate and spread. In this scenario, physical dividers are shown to create separation. Is is not clear if this is effective or not as there are no definative tests to determine this yet. 6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
1'-6''
1'-6''
2'-4''
2'-4''
Open Studio Space - Pre-Covid
Size: 1,050 square feet Occupancy: 12 people (88 sf per person)
AUG 10, 2020
Open Studio Space - Social Distancing of 6’-0” Plus Dividers Size: 1,050 square feet Occupancy: 12 people (88 sf per person) Utility Rate: 100% of Pre-Covid Occupancy
MANUAL OF PHYSICAL DISTANCING
P. 53
CLASSROOM STUDY Individual Equipment Stations Each piece of equipment needs to have a safe zone around it that is supplemental to the safety and usage requirements that are associated with any given piece of equipment.
If multiple users will engage equipment areas, each station will need to be cleaned between users to ensure virus on surfaces is removed or use of PPE to mitigate transmission.
Additional distance is recommended to exceed the 6’-0” distance of the user located directly at the equipment. Spacing needs to anticipate users moving around equipment, so measured from the edge of equipment to define boundary. Thus equipment locations to be spaced apart to allow a minimum of 6’ separation between equipment stations. Proper ventilation for equipment needs to be maintained according to the equipments requirements. Supplemental ventilation to diffuse viral load should be considered. Space behind equipment should anticipate movement by user and need for safe circulation. Space in front (if there isn’t a wall or boundary) should also be anticipated.
3'-0"
6'-0"
6'-0"
6'-0 8'-0
" S
IE R A V
"
8'-0"
3'-0"
3'-0"
6'-0"
3'-0"
Space between stations provides social distance. Area of the equipment to be spaced apart will depend on how individuals use equipment.
6'-0
"
8'-0
AUG 10, 2020
8'-0"
6'-0"
"
MANUAL OF PHYSICAL DISTANCING
P. 54
CLASSROOM STUDY Lecture Hall Large gathering spaces create more challenges to collective learning. Larger groups raise the risk of infection spread. Social distancing measures significantly impact room occupancy capacity. Circulation into and out of the internal rows are a challenge in looking to keep social distance. 6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Lecture Hall - Pre-Covid
Size: 2,300 square feet Occupancy: 108 people (21 sf per person)
AUG 10, 2020
Lecture Hall - Social Distancing of 6’-0”
Size: 2,300 square feet Occupancy: 31 people (74 sf per person) Utility Rate: 29% of Pre-Covid Occupancy
MANUAL OF PHYSICAL DISTANCING
P. 55
CLASSROOM STUDY Library Use of libraries create collective gathering and circulation challenges, as well as some opportunities for work areas that may be isolated. Number of users raises different issues in regards to transmission through shared surfaces, library materials, and objects of collections.
6-0” social distancing assumes an unrealistic condition where each person is static and does not take into account viral accumulations or aerosol risk.
Individual work station may provide socially-isolated work areas, but risk of transmission through surface contaminants by multiple users is at issue.
Circulation through narrow stacks would need to be directional to avoid crossing. Cleaning of shelves and books, if open stack, will need to be anticipated with regard to impact on archived materials, papers, and bindings.
Library - Pre-Covid
Size: 4,850 square feet Occupancy: 34 people (143 sf per person)
AUG 10, 2020
Library - Social Distancing of 6’-0”
Size: 4,850 square feet Occupancy: 24 people (202 sf per person) Utility Rate: 71% of Pre-Covid Occupancy
MANUAL OF PHYSICAL DISTANCING
Information areas and central circulation would require additional social spacing and protection for librarians and staff.
P. 56
CASE STUDY: SHARED SPACES IN BUILDINGS
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 57
SHARED SPACES IN BUILDINGS Circulation Challenges: Existing Entrance floor The recommended 6’-0” social distancing rules to meet Covid-19 have direct implications on the use of shared spaces within buildings where there will be overlaps between different users as different times. These public spaces, including entrances, common corridors, staircases, elevators, bathrooms and other collective areas pose challenges to how buildings were previously used. Maintaining a 6’-0” distance will be a challenge. This social distancing measure is only a precautionary preventative measure and does not reduce all risk that is associated with the transmission of Covid-19, that includes surface contamination and aerosol distribution. Based on case-study work, closed interior environments raise significantly the risk of transmission, especially in spaces where there is occupancy over a longer duration.
Entry security and reception services pose risks to those who work in these positions. Additional precautions should be considered to provide protection.
Elevators will be pinch-points, with social distancing measures in these enclosed small spaces limiting occupancy and use.
Shared circulation paths create two way crossings and risk. Shifting circulation patterns to one-way need to be anticipated only with compliance of current fire and building codes.
Entrances provide points of crossing and potential challenges for maintaining social distance, depending on time of use and number of users and visitors.
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Collective shared spaces such as lobby lounges, gathering rooms, meeting areas and laundry facilities are key areas for reconsideration and establishing new protocols for use.
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Staircases pose a challenge to keeping distance, especially when these are used in two directions. Attention to fire code compliance.
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SHARED SPACES IN BUILDINGS Circulation Challenges: Typical Shared Office Floor While the most significant area of overlap for shared users in a building is often the first floor entrance sequence, buildings that have shared space and facilities on upper floors run similar risks in transmission of Covid-19. These areas include common lobbies, elevator vestibules, corridors, staircases, and restrooms. Each of these would need to be examined to enable users to safely keep to physical distancing of 6 feet, as well as enhanced cleaning and reduction of shared surfaces. Bathrooms in particular are areas of increased concern given the small space and activity which increases the spread of virus droplets and aerosolized contaminants.
Elevators will be pinch-points, with social distancing measures in these enclosed small spaces limiting occupancy and use.
Shared circulation paths create two way crossings and risk. Shifting circulation patterns to one-way need to be anticipated only with compliance of current fire and building codes.
Common restrooms are areas for close examination and reorganization given the tight spacing and the type of use that these facilities normally handle.
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Staircases pose a challenge to keeping distance, especially when these are used in two directions. Attention to fire code compliance.
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SHARED SPACES IN BUILDINGS AIA Guidelines AIA, (May 28, 2020) Re-occupancy Assessment Tool V1.0. https://www.aia.org/resources/6292441-re-occupancy-assessment-tool
Architecture and engineering controls: Building envelope
The American Institute of Architects (AIA) put out a re-occupancy assessment tool to help facility managers and architects assess risk and determine ways to adjust to the impact of Covid-19. This tool combines the CDC guidelines while identifying the spatial separation required for physical distancing. The AIA encourages planners and architects to use a 6 foot radius as a planning unit as it accommodates someone moving between people and to consider a range of good practices when looking at individual components of a building to mitigate transmission risk. These are some of the aspects covered in this assessment tool.
Non Structural partitions and opening Utilize natural daylight if possible
Mechanical and Passive ventilation Utilize operable windows for outside air intake when possible.
Architecture and engineering controls: Furnishing and furniture
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Non Structural partitions and opening
Non Structural partitions and opening
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Create touchless entry eg, provide automatic door opening utilizing proximity sensors.Â
Create touchless entry eg, provide automatic door opening utilizing proximity sensors.Â
Provide cleanable, transparent films over surfaces such as elevator buttons
Provide cleanable, transparent films over surfaces
Install physical barriers such as clear plastic partitions or sneeze guards.
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SHARED SPACES IN BUILDINGS Circulation Study: Stairs
4. OFFICE ENTRY • Do not linger in hallways and stairwells. • Travel on right side of corridor • Use hand sanitizer or wash hands upon entering room
The following diagram looks at an entrance sequence using stairs to go from outside, through a public entrance, corridor, staircase and corridor to arrive at a designated office or lab. Signs are shown to help organize behavior.
THIS STAIRWELL IS FOR UPWARD TRAVEL ONLY.
3. STAIRWELL • Note direction of stairwell • Do not linger in
IN CASE OF EMERGENCY PLEASE USE THE NEAREST STAIRWELL. Signage, if one directional
THESE DOORS ARE ENTRY ONLY. PLEASE USE THE [BLANK] DOORS TO EXIT.
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2. CORRIDOR (72” TWO-WAY) • Do not linger in hallways • Note if corridor is one- or two-way • Travel on right side of hallway
1. BUILDING ENTRY • Avoid sharing vestibule with others • Use hand sanitizer upon entering
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THIS CORRIDOR IS 6’-0” WIDE. PLEASE BE MINDFUL OF PHYSICAL DISTANCE WHEN PASSING OTHERS. Signage at each end of corridor, varies based on corridor width
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SHARED SPACES IN BUILDINGS Circulation Study: Elevator The following diagram looks at an entrance sequence using elevators to go from outside, through a public entrance, corridor, elevator and corridor to arrive at a designated office or lab. Signs are shown to help organize behavior.
4. OFFICE ENTRY • Do not linger in hallways and stairwells. • Travel on right side of corridor • Use hand sanitizer or wash hands upon entering room
3. ELEVATOR • Limit elevator use and try to use the stairs • Limit to one person per elevator car, if possible. If more than one person must use the elevator at the same time, stand in opposite corners and face away from each other. • Maintain social distancing when waiting for the elevator. • Avoid touching buttons directly. If you do, use sanitizer or wash hands.
ONLY ONE PERSON PERMITTED IN ELEVATOR AT A TIME. PLEASE USE STAIRS.
THESE DOORS ARE ENTRY ONLY. PLEASE USE THE [BLANK] DOORS TO EXIT.
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2. CORRIDOR (72” TWO-WAY) • Do not linger in hallways • Note if corridor is one- or two-way • Travel on right side of hallway
1. BUILDING ENTRY • Avoid sharing vestibule with others • Use hand sanitizer upon entering
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THIS CORRIDOR IS 6’-0” WIDE. PLEASE BE MINDFUL OF PHYSICAL DISTANCE WHEN PASSING OTHERS. Signage at each end of corridor, varies based on corridor width
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SHARED SPACES IN BUILDINGS Restroom Use
2A. RESTROOM (3+ OCCUPANT TYPE) • To maintain distance some fixtures may be blocked off • People entering should use verbal confirmation (knock) to verify occupancy • If there is a line, keep it outside of the restroom, maintaining six feet separation. • Wash your hands for at least 20 seconds. • Use paper towels to dry your hands and to shut off faucets. • Avoid using hand dryers. • Use a paper towel to manipulate the door, if necessary.
The following diagram looks at modifications to shared restrooms to minimize overlap between users and potentially reduce risk.
1. OFFICE EXIT • Allow people already in corridor to pass before proceeding • Note if corridor is one- or two-way • Travel on right side of hallway 2B. RESTROOM (2 MAX OCCUPANT TYPE) • To maintain distance some fixtures may be blocked off • People entering should use verbal confirmation (knock) to verify occupancy • If there is a line, keep it outside of the restroom, maintaining six feet separation. • Wash your hands for at least 20 seconds. • Use paper towels to dry your hands and to shut off faucets. • Avoid using hand dryers. • Use a paper towel to manipulate the door, if necessary.
PLEASE WASH HANDS FOR MIN. 20 SECONDS. USE PAPER TOWELS TO DRY HANDS, TURN OFF FAUCET AND MANIPULATE DOOR.
RESTROOM OCCUPANCY IS LIMITED TO # PEOPLE. PLEASE VERBALLY CONFIRM OCCUPANCY (knock) BEFORE ENTERING.
THIS CORRIDOR IS 6’-0” WIDE. PLEASE BE MINDFUL OF PHYSICAL DISTANCE WHEN PASSING OTHERS. Signage at each end of corridor, varies based on corridor width
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6’-0” Floor Graphics, varies based on corridor width
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URBAN SPACE CONDITIONS: STREETS + SIDEWALKS
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URBAN RESEARCH TERRITORIES New York City is the early epicenter of the outbreak in the United States, and as such, is well situated to serve as a case study for this research. While tactics are explored for the specific conditions of New York and tailored to its agencies, spatial conditions and stakeholders, it is anticipated that this design manual / visual toolkit can be adopted and deployed in urban areas generally.
How can subway stations and cars be rethought to facilitate and encourage social distancing and shifting densities of ridership?
The area of investigation will be the public spaces of the city with particular focus on transit systems (subway, buses, bicycle infrastructure), streetscapes (sidewalks, plazas) and parks (recreation areas, promenades, playgrounds). The following diagrams identifies some of the possible opportunities for design strategies for synthesizing density and physical distancing toward a better urban future.
What new components of streetscape design might augment public health, such as hand-sanitizing stations or temperature checkpoints?
How can the cityâ&#x20AC;&#x2122;s sidewalks and crosswalks encourage safe pedestrian coexistence, providing visual cues and metrics that encode required distancing through paving patterns and street markings?
How can playgrounds be redesigned with equipment and landscaping that facilitates public safety and hygiene for both parents and children?
How can the vast territory of vehicular streets be leveraged to provide augmented pedestrian space on a temporal basis while maintaining accessibility and functionality?
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How can an emphasis on enhanced bicycle infrastructure, from bike lanes to parking facilities, contribute both to reduced transmission and increased environmental benefits while reducing crowding on more vulnerable forms of public transit?
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How can common elements of urban furniture such as benches, charging stations and bus stops become adaptable to physical distancing, accommodating multiple modes and proximities of use?
How might emerging diagnostic technologies be incorporated into the public spaces of the city, providing both emergency monitoring and ongoing vigilance over longer time periods?
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STREETSCAPE ANALYSIS Small Avenue 100 pedestrians No distancing No modifications A typical small avenue with one-way vehicular traffic could expect 100 pedestrians at a peak time. Moving from left to right, this streetscape has average width sidewalks, a parking and/or loading lane, several lanes of one-way traffic, a dedicated bus lane. It does not have a dedicated bike lane nor a shared bike lane. Crosswalks and bus stops represent the most congested conditions.
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STREETSCAPE ANALYSIS Small Avenue 100 pedestrians 6 ft distancing No modifications While the sidewalks can accommodate the same number of pedestrians even with physical distancing, this assumes unrealistic uniform patterns and speeds of walking. It also can barely accommodate the area taken up by various street furniture, signage, trash receptacles that are typically found at the curb of New York City streets.
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STREETSCAPE ANALYSIS Small Avenue
Typical street furniture located at curb could be used to clarify division between pedestrian traffic directions.
100 pedestrians 6 ft distancing Expanded zones for pedestrians and cyclists This proposal expands both the territories for pedestrians and bicycles, while a parking lane and one lane of traffic are eliminated. Expanding both sidewalks allows for pedestrian traffic to move in both uptown and downtown directions on either side of the avenue.
Even with expanded sidewalk zones, pedestrians may need to travel in designated directions to avoid congestion.
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Pedestrian traffic at corners would need to be coordinated with perpendicular streets for increased safety from faster modes traffic and to ease congestion.
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STREETSCAPE ANALYSIS Small Avenue Comparative pre- and post-COVID diagrams.
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STREETSCAPE ANALYSIS Crosstown Street 112 pedestrians No distancing No modifications A typical crosstown street in Manhattan with two-way vehicular traffic could expect roughly 112 pedestrians at any time. Each direction of traffic has relatively wide sidewalks, a parking and/or loading lane, a dedicated bus lane, and a vehicular traffic lane. It does not have a dedicated bike lane nor a shared bike lane. Crosswalks and bus stops represent the most congested conditions.
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STREETSCAPE ANALYSIS Crosstown Street 112 pedestrians 6 ft distancing No modifications While the sidewalks can accommodate the same number of pedestrians even with physical distancing, this assumes unrealistic uniform patterns and speeds of walking. It also can barely accommodate the area taken up by various street furniture, specifically large newsstands and subway entrances, as well as signage and trash receptacles that are typically found at the curb of New York City streets.
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STREETSCAPE ANALYSIS Crosstown Street
Typical street furniture located at curb could be used to clarify division between pedestrian traffic directions.
112 pedestrians 6 ft distancing Expanded zones for pedestrians This proposal expands the territory for pedestrians, while parking lanes on each side of the street are eliminated. Expanding both sidewalks allows for pedestrian traffic to move in both uptown and downtown directions on either side of the street.
Even with expanded sidewalk zones, pedestrians may need to travel in designated directions to avoid congestion.
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Buffer zones—wide lane stripping and addition of cones—between modes of traffic could increase safety. AUG 10, 2020
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Pedestrian traffic at corners would need to be coordinated with perpendicular streets for increased safety from faster modes traffic and to ease congestion.
P. 72
STREETSCAPE ANALYSIS Crosstown Street
Typical street furniture located at curb could be used to clarify division between pedestrian traffic directions.
112 pedestrians 6 ft distancing Expanded zones for pedestrians and cyclists This proposal expands the territory for pedestrians and cyclists, while parking lanes on each side of the street are eliminated and bus and vehicular traffic lanes are merged.
Even with expanded sidewalk zones, pedestrians may need to travel in designated directions to avoid congestion.
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Buffer zones—wide lane stripping and addition of cones—between modes of traffic could increase safety. AUG 10, 2020
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Pedestrian traffic at corners would need to be coordinated with perpendicular streets for increased safety from faster modes traffic and to ease congestion.
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STREETSCAPE ANALYSIS Crosstown Street Comparative pre- and postCOVID diagrams.
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STREETSCAPE ANALYSIS Residential Street 12 pedestrians No distancing No modifications A typical residential street in any borough with one-way vehicular traffic could expect roughly 12 pedestrians at any time. Sidewalks are relatively narrow particularly since they include consistent planters along the curb. There is street parking on either side of the street. It does not have a dedicated bike lane nor a shared bike lane. Crosswalks represent the most congested conditions.
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STREETSCAPE ANALYSIS Residential Street 12 pedestrians 6 ft distancing No modifications Given the low number of pedestrians, residential streets can accommodate the typical number of pedestrians even with physical distancing. Though congestion may occur when pedestrians pass each other particularly when sidewalks narrow at planters.
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STREETSCAPE ANALYSIS Residential Street 12 pedestrians 6 ft distancing Expanded zones for cyclists This proposal expands the territory for cyclists only, while parking lane on one side of the street is eliminated.
Sidewalks remain narrow given typically low pedestrian traffic.
Tree planters at curbs present a challenge for two direction pedestrian traffic as sidewalk at those points narrow to 5 ft.
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STREETSCAPE ANALYSIS Residential Street Comparative pre- and post-COVID diagrams.
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Y AC M R HA
SIDEWALK ZONES: Overview
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While streets and sidewalks suggest linear and directional flows of movement, typical urban conditions comprise a multiplicity of divergent trajectories, physical impediments and complex exchanges between the collective space of the pedestrian and the interior spaces of buildings. These conditions imply zones of turbulence which complicate and problematize the control of movement relative to spatial distancing. In the following, we examine a representative sample of urban scenarios to illustrate their implications for the City during the current crisis and as activity resumes. In each, the intent is to identify issues and challenges as well as emergent practices and behaviors. A next phase of investigations will propose more precise recommendations and concrete proposals that negotiate between the demands of spatial distancing, the diversity of interactions and itineraries that characterize urban life, and the increasing demand on sidewalks as exterior activity is less likely to spread Covid-19 compared to the same activity occuring inside.
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COMMERCIAL STOREFRONT: Large Retail Large scale retail entails the exchange between the store interior and the space of the sidewalk, complicated by waiting times and the necessity for queuing. Grocery chains, for example, are generating extended exterior lines compounded by necessary distancing and potentially impeding movement along adjacent sidewalks and building entries.
Clear designation of adjacent building entries could help to mitigate potential conflicts between queuing patrons and building occupants
Shown: 6th Avenue, Manhattan Grocery Store
Store entrances and waiting areas can be clearly indicated to sequester queuing zones from sidewalk traffic and allow for distancing protocols. Exit and entry doors should be clearly differentiated to negotiate directional movement.
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Store personnel can be deployed to monitor safe queuing practices and to help prevent conflicts between lines of patrons and passing pedestrians.
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P. 80
COMMERCIAL STOREFRONT: Outdoor Dining Outdoor dining, while a desirable component of a vital urban environment, represents specific challenges to the sidewalk under spatial distancing, reducing usable width for pedestrians and creating potential conflicts between diners and passers-by.
Outdoor dining areas will need to be rethought to accommodate required spatial distancing between patrons.
Shown: LES Restaurant
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How can the typical temporary barrier be adapted to provide both clear designation of dining territories and greater safety in relation to nearby pedestrians?
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COMMERCIAL STOREFRONT: Small Retail The smaller scale commercial typology which characterizes many areas of the City offers a diversity of goods and services without the risks of overcrowding associated with major chains. At the same time, bodega’s, deli’s and other similar establishments typically have a more fluid relation to public space, often occupying portions of a more dimensionally limited sidewalk and creating a range of challenges and possible exchanges.
Can external displays be deployed to help designate entry zones and protect store entrances? Care should be taken to not reduce visibility or space for safe movement.
Can vacant and disused storefronts be re-purposed for new public functions?
Shown: Grand Street, Brooklyn Bodega To-Go Window
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As carry out dining is likely to remain a popular option, restaurants may consider installing a To-Go window or designating areas to safely exchange food and other goods.
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When businesses are unable to control pedestrian traffic flow at entrances, use of signage and ground markings can promote heightened caution and awareness. They should also keep these areas free of clutter and other visual obstructions.
Benches and similar street furniture can be modified or adapted to accommodate spatial distancing and indicate caution relative to high touch surfaces.
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WORKPLACE: Large Office Entrance As commercial activity resumes, large office buildings present the challenge of safely moving large numbers of workers from the sidewalk to the building interior and onto limited vertical transportation. Waiting times for elevators could generate external queues that will need to occupy portions of the sidewalk. While temporal sequencing and restructured work days can help to mitigate these issues, spatial strategies and procedures can help to minimize conflicts and threats to safety.
Since elevator capacity and waiting times are likely to be an issue, priority should be given to the physically challenged and those on upper floors while workers on lower floors who are able should be encouraged to use the stairs as much as practical.
Shown: 42nd Street Office Tower
Clearly designating entry and exit sequences at large office buildings can mitigate any congestion that would occur in lobbies and elevators and prevent possible conflicts with passing pedestrians.
Bus pavilions will no longer be able to be used to capacity, however can designate areas to wait with appropriate spacing nearby.
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WORKPLACE: Small Office Entrance Typical commercial streets serving smaller scale office buildings and retail will still need to negotiate between entry and exit sequences and sidewalk pedestrian movement, clearly designating entries and directionality where possible and providing for safe interactions between building users and pedestrians sharing limited sidewalk space.
Sidewalk scaffolding prevents safe passage in two directions consistent with spatial distancing. Consideration should be given to controlling pedestrian traffic flow through signage or other means
Shown: Typical Chelsea Street
Clear indication of entries and directionality can help mitigate congestion and promote proper spacing.
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RESIDENTIAL: Multi-Unit Tower Entrance Larger residential buildings often have entry awnings that overlap sidewalk space, creating possible constriction to movement but also visually signaling the presence of an entryway.
Residential districts with large apartment complexes will need to safely accommodate the more frequent and continuous individual comings and goings of residents, often with less sidewalk territory to allow for optimal distancing. Varying typologies each represent a distinct set of challenges and opportunities for fostering safe social interaction. Shown: Typical UES Apartment Building
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Safe use of awning zones could be monitored by a door person or other residents of the building.
Can awnings designate space for stasis within the flow of the public sidewalk?
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RESIDENTIAL: Public Housing Shown: Sedgwick Houses, The Bronx
Waiting zones for elevator queues and markings that designate points of entry could facilitate with the circulation of pedestrian traffic.
Green space adjacent to public housing, while typically unavailable for use, could provide an outdoor place for residents to gather in a fresh air environment.
Ramps and accessible entrances should be well marked and possibly employ signage to indicate their safe usage.
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RESIDENTIAL: Manhattan / Brooklyn / Row House Block
Raised stoops and setbacks create a buffer between the act of entering and exiting the building and the sidewalk.
Traditional urban housing types may offer unique opportunities for negotiating between requirements for spatial distancing and the collective life of their residents. Architectural features like front stoops and garden setbacks provide buffer zones to more safely engage public space, access outside air and sunlight and promote a more active street life with lowered risk. Shown: Park Slope Row Houses
Private outdoor spaces like stoops and yards can provide spaces for safe outdoor gathering.
While the front stoop provides a measure of safety, care should be taken to not impede building access or create hazards for passer’s by.
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RESIDENTIAL: Brooklyn / Queens / Bronx Row House Block Shown: Ridgewood Row Houses
Stoops and yards are a good place to safely gather outdoors.
Residents should be mindful of entrances and steps that abut directly with the sidewalk and also be aware of tree wells that significantly reduce the sidewalk’s width.
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COMMERCIAL SIDEWALKS Street Parking: As Is Traditional sidewalks use public space that could be adapted for pedestrian and civic uses which instead are programed for car parking. This discourages walkable neighborhoods, adds congestion to the city, and under utilizes public spaces.
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COMMERCIAL SIDEWALKS Parking Lane Open to Pedestrians • Side walk is extended into parking lane • Barricades provide protection for pedestrians and clearly separate vehicular zones from pedestrian zones • Booths are used for carry out orders • Restaurants are able to extend further into the sidewalk or occupy areas protected by barricades
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COMMERCIAL SIDEWALKS Protected Bike Lane • Sidewalk is extended into parking lane • Sidewalk extension and bike lane use infill padding (short-term) or asphalt (long-term) to be at the same grade as the existing sidewalk providing protection to cyclists and pedestrian from vehicular traffic • Planters and barricades are used as a buffer between cyclists and pedestrians • Barricades employ bench modification to provided cyclists and pedestrian with a place to rest
Y AC
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COMMERCIAL SIDEWALKS Parking Adaptations: Low Cost As business expand into sidewalks and parking spaces are converted into dining areas and made part of the cityâ&#x20AC;&#x2122;s pedestrian space, they are faced with choices regarding how to expand the street in a safe manner, that is cost-effective, and which can host a variety of programs. Here are low-cost design options which diagram possibilities for temporary spaces.
Ground coverings like rubber mats or turf cover prevent dust particles from kicking up.
Water-filled, polyethylene barriers provide protection and are easily deployable.
AUG 10, 2020
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COMMERCIAL SIDEWALKS Parking Adaptations: Medium Cost As business expand into sidewalks and parking spaces are converted into dining areas and made part of the cityâ&#x20AC;&#x2122;s pedestrian space, they are faced with choices regarding how to expand the street in a safe manner, that is cost-effective, and which can host a variety of programs. Here are medium-cost design options which diagram possibilities for temporary spaces.
More permant parklet construction levels the program expansion with the curb. This requires a structure to elevate the surface. The assembly shown here uses dimensional lumber and whole, standardsized plywood sheets. The structure leaves gaps underneath to allow for water runoff and drainage to the street gutter.
Parklet spaces allow for non-commercial expansion of the pedestrian areas of the street. Planters, built from dimensional plywood provide protection while segmenting spaces for social distancing.
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 93
COMMERCIAL SIDEWALKS Parking Adaptations: High Cost As business expand into sidewalks and parking spaces are converted into dining areas and made part of the cityâ&#x20AC;&#x2122;s pedestrian space, they are faced with choices regarding how to expand the street in a safe manner, that is cost-effective, and which can host a variety of programs. Higher-cost interventions, such as these, are semi-permanent and provide the most durability to exterior elements.
Higher-cost street expansions utilize adjustable pedals which can level the ground surface since street surfaces are concave surface. The ground surface is constructed from more durable products like treated lumber or synthetic products while the skirt is made of perforated metal to allow for water drainage and evaporation.
In addition to more permanent features such as fabric canopies, higher-cost street expansions may utilize features such as lighting which require electrical hookups but expand usage of these spaces into the night.
With more study construction, ba4riers can be affixed to the metal substructure and, subsequently, be both higher-quality and thinner. Metal guardrails and bollards provide the same level of protection while maintaining the visual continuity across the street.
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STREET MOBILITY: COMMERCIAL TWO WAY STREET Existing Condition Many of New York’s streets prioritize vehicular transportation even though a majority of its residents use pedestrian modes of travel like subways and buses. The result is congested sidewalks and a large area of public streets designated for parking. These streets often lack bike lanes and sufficient space for commercial retailers and restaurants to expand their frontage into the sidewalk without impeding on pedestrian travel.
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STREET MOBILITY: COMMERCIAL TWO WAY STREET DOT Street Seats and Bike Lanes Initiatives currently in place by the DOT include the expansion of bike lanes throughout the city and Street Seats, in which parking spaces are replaced with protected seating areas to include chairs, tables, benches, and natural vegetation. These zones are an extension of the sidewalk and can be used in tandem with adjacent businesses.
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STREET MOBILITY: COMMERCIAL TWO WAY STREET COVID-19 Physical Distancing Measures With social distancing protocols now in place and a better understanding of the virus’s transmission through aerosol particles there is an increased urgency for outdoor public space, especially along the commercial corridors that sustain a community’s everyday needs. Measures like Open Restaurants allows businesses to more rapidly expand into nearby sidewalk and parking zones to provide outdoor dining space. Ground markings can be a useful way to designate entrance thresholds and waiting zones.
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STREET MOBILITY: COMMERCIAL TWO WAY STREET Future Street Condition Best Practices These temporary measures can also be seen as a way to envision the future of New York’s streets. A more equitable division of street space can be distributed amongst pedestrians and vehicles. The widening of sidewalks allows more space for business frontage, creating a more permeable storefront that better engages the sidewalk and community. Bike lanes could gain greater prioritization through widening and added protection with the installation of their own curb.
Com Sp merc ace ial
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STREET MOBILITY: COMMERCIAL TWO WAY STREET Future Street Condition Suboptimal While a fully protected bike lane is appropriate in some parts of the city, instances where bike lanes follow vehicular traffic patterns should avoid coupling both directions of travel. This method is problematic at their points of termination making often complex and even dangerous intersection crossings for cyclists. On most slower speed roads, it is best for the bike lane to follow the same direction of travel as the adjacent driving lane.
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STREET MOBILITY: COMMERCIAL ONE WAY STREET Existing Condition Many of New York’s streets prioritize vehicular transportation even though a majority of its residents use pedestrian modes of travel like subways and buses. The result is congested sidewalks and a large area of public streets designated for parking. These streets often lack bike lanes and sufficient space for commercial retailers and restaurants to expand their frontage into the sidewalk without impeding on pedestrian travel.
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STREET MOBILITY: COMMERCIAL ONE WAY STREET DOT Street Seats and Bike Lane Initiatives currently in place by the DOT include the expansion of bike lanes throughout the city and Street Seats, in which parking spaces are replaced with protected seating areas to include chairs, tables, benches, and natural vegetation. These zones are an extension of the sidewalk and can be used in tandem with adjacent businesses.
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STREET MOBILITY: COMMERCIAL ONE WAY STREET COVID-19 Physical Distancing Measures With social distancing protocols now in place and a better understanding of the virus’s transmission through aerosol particles there is an increased urgency for outdoor public space, especially along the commercial corridors that sustain a community’s everyday needs. Measures like Open Restaurants allows businesses to more rapidly expand into nearby sidewalk and parking zones to provide outdoor dining space. Ground markings can be a useful way to designate entrance thresholds and waiting zones.
Com Sp merc ace ial
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STREET MOBILITY: COMMERCIAL ONE WAY STREET Future Street Condition These temporary measures can also be seen as a way to envision the future of New York’s streets. A more equitable division of street space can be distributed amongst pedestrians and vehicles. The widening of sidewalks allows more space for business frontage, creating a more permeable storefront that better engages the sidewalk and community. Bike lanes could gain greater prioritization through widening and added protection with the installation of their own curb.
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STREETSCAPES: Commercial Street Typologies AUTOMOBILE In response to COVID-19, there has been a growing push in many cities to expand the public realm, specifically through the rapid shortterm takeover of streets for various uses. The commercial street typology presents a unique opportunity to develop possible new ways of creating public spaces and expanding the realm of the sidewalk for pedestrians and cyclists alike. The matrix presented here gives a variety of possible uses, both short and long-term transformations, of a commercial street to give options based on timeline, scope and budget. It looks to show a few options that suggest a myriad of uses that might take place here.
PEDESTRIAN
typ. 1600 SF zone
typ. 1600 SF zone
typ. 1600 SF zone
37% 21% 14% 28%
37% 600 SF pedestrian 63% 1000 SF open street *300 SF emergency vehic
100% 1600 SF pedestrian *300 SF emergency vehic
600 340 220 440
SF SF SF SF
pedestrian parking biking automobile
Market Street Conversion
Recreational Street Conversion
Restaurant Street Conversion AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 104
STREETSCAPES: Market Street Short-Term The short-term market street displays an existing typology of temporary street takeover. Pop-up tents and fold-out tables allow for local vendors and shops to bring their goods to sell on this streetscape for an afternoon. Additional seating and furniture is suggested as well to prevent the overcrowding of the streetspace and encourage dining and leisure.
Provide tents and foldable tables for local vendors to sell goods on street Temporary barriers and cones at street entry to stop thru-traffic and signify slow street Allow plenty of open street space to avoiding crowding and bunching of pedestrians around vendor stalls
Incorporate removable seating and dining furniture such as cafe tables and umbrellas
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 105
STREETSCAPES: Market Street Long-Term The long-term market or retail-focused streetscape proposes a full removal of auto access except for emergency vehicles and replacement with continuous pedestrian plaza. Paintings or floor pattern changes along the main thoroughfare are encouraged to help with flow of occupants. A variety of stall types are encouraged as well as spill out zones to allow for access to the existing storefronts on the commercial street.
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
Provide spill out zones from main promenade for seating and access to existing shops and storefronts on commercial street
Incorporate long-term rentable kiosks for local small business vendors
Install continuous pavement along entire street to create one open plaza space. Provide painting pattern along primary promenade area to help identify zones for movement or seating
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 106
STREETSCAPES: Recreational Street Short-Term The short-term recreational street presents a temporary intervention of interactive elements for active play. By incorporating elements like paint or removable objects like ping-pong tables, activation of the more commercial street for public uses can become possible. Bringing on local business and fitness groups is encouraged to provide additional classes or spaces for group training to further activate the street.
Encourage local businesses to host wellness events such as yoga, exercise or meditation Temporary barriers and cones at street entry to stop thru traffic and signify slow street
Provide temporary play structures like see-saws or ping-pong tables for small group activities
Temporary painting of various games or activities such as soccer, basketball or roller-hockey
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 107
STREETSCAPES: Recreational Street Long-Term The long-term recreational street proposes a larger takeover of the street and removal of automobile access with the exception of emergency vehicles to produce a pedestrian-focused plaza. By providing a variety of playful elements and structures that can be used in multiple ways, the street can become a much more inhabitable public zone for recreation. It is encouraged to bring on local vendors and groups to set up small events or pop-ups within the plaza space to further enliven the experience.
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
Install continuous pavement along entire street to create one open plaza space. Provide painting pattern along primary promenade area to help identify zones for movement or seating
More permanent play structures installed that present a variety of types of play and interaction.
Encourage presence of local street vendors for food, drink and retail
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 108
STREETSCAPES: Restaurant Street Short-Term The short-term restaurant street presents the potential for maximum outdoor dining to allow existing local restaurants to maintain their business. Temporary bollards and barriers are encouraged and vary based on each individual ownerâ&#x20AC;&#x2122;s preference and can help to create a varied dining experience. The restaurant dining spaces take on the once existing parking spaces in front of each restaurant, leaving the street open for pedestrians and cyclists while also allowing for curbside pick-up, deliveries and emergency vehicles when needed.
Allow existing businesses and restaurants to expand seating and outdoor dining into parking lanes. Incorporate temporary blockades from street Temporary barriers and cones at street entry to stop thru traffic and signify slow street
Maintain large open street lanes for morning food deliveries and curbside pickup as well as expanded pedestrian space
Encourage variety of temporary dining experiences or use of existing furniture in restaurant to bring onto street
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 109
STREETSCAPES: Restaurant Street Long-Term The long-term restaurant street proposes a more holistic intervention onto the streetscape by fulling removing automobiles except for emergency vehicles and transforming the street into one continuous pedestrian plaza. Shown here, a continuous central promenade for walkers is encouraged through painting on the paving and a variety of dining types encouraged. Additionally, vendors and retail of other types can be mixed into the streetscape as well as purely public seating furniture unrelated to a single restaurant.
Encourage presence of local street vendors for other retail purposes like bookstores
Install continuous pavement along entire street to create one open plaza space. Provide painting pattern along primary promenade area to help identify zones for movement or seating
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
Encourage variety of temporary dining experiences or use of existing furniture in restaurant to bring onto street
Provide additional seating and planters for leisure space unassociated with any specific storefront or retail space
Commercial Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 110
STREETSCAPES: Urban Street Typologies AUTOMOBILE In response to COVID-19, there has been a growing push in many cities to expand the public realm, specifically through the rapid short-term takeover of streets for various uses. The large urban street typology presents an opportunity to develop new kinds of public spaces that can host larger-scale events, markets and other types of public programming. This series of drawing presents a typical crosstown street with two-way vehicular traffic, where each direction of traffic has a relatively wide sidewalk, a parking and/or loading lane, a dedicated bus lane and a vehicular traffic lane. The matrix presented on this page gives on overview of the variety of possible uses of a larger urban street. Both short and long-term transformations are diagrammed, to give specific options based on timeline, scope and budget.
PEDESTRIAN
typ. 1000 SF zone
typ. 1000 SF zone
typ. 1000 SF zone
40% 16.5% 19.5% 24%
76% 760 SF pedestrian 24% 240 SF market stalls *195 SF emergency vehicle
100% 1000 SF pedestrian
400 165 195 240
SF SF SF SF
pedestrian parking automobile bus
Marketplace Conversion
Event Space Conversion
Recreational Zone Conversion AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 111
STREETSCAPES: Marketplace Short-Term The short-term marketplace builds off of the existing streetscape and uses the given car lanes to determine the arrangement of the market stalls. The commercial activity of the market stalls takes over the two designated bus lanes. Pedestrians use the two car lanes as well as two parking lanes, which enables a two-way pedestrian traffic circulation that allows for the avoidance of close physcial contact. The short-term transformation of an urban street into a marketplace as shown in the drawing can be implemented within a single day.
Existing streetscape elements like kiosks, traffic lights, bike racks, etc. are maintained in this temporary transformation. The plastic barriers indicate that the transformation is temporary. The barriers stop traffic and can easily be installed or removed within a single day.
The different types of tables, tents and market stalls demonstrate the flexibility of the space that can serve market vendors of different kinds and different sizes.
Urban Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
The arrows can be painted or taped onto the ground and indicate the two-way pedestrian circulation of the marketplace. This system enables pedestrians to physically distance themselves from others while strolling through the marketplace.
P. 112
STREETSCAPES: Marketplace Long-Term The long-term marketplace suggests a more holistic and permanent solution to automobile removal on a large urban avenue. Though the new market street maintains a sense of sidewalk vs. street in order to facilitate access for emergency vehicles and delivery trucks, the paving transitions towards a more pedestrian-friendly space as the curb is removed in order to create a planar surface.
Though the new streetscape maintains a sense of sidewalk vs. street, the curb is removed to create a pedestrian-friendly, continuous flat surface. Bollards are installed at the entry to the plaza to prevent car access. The bollards are removable for emergency vehicle access and well as delivery trucks.
Permanent, stationary market stalls are installed in the street and allow for a regular daily or weekly market to happen for an extended period of time.
Trees embellish the streetscape and create the feel of a park in a large urban space.
The installation of permanent tables and chairs create new seating opportunities that allow for people to stop up, meet, sit down, rest, talk or people watch.
Urban Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 113
STREETSCAPES: Event Space Short-Term
Existing streetscape elements like kiosks, traffic lights, bike racks, etc. are maintained in this temporary transformation.
The urban street as an event space can comprise a variety of noncommercial programs and activities such as cultural, visual and acoustic events. Potential program options include but are not limited to concerts, theater performances, dance shows, outdoor movie theaters, art exhibitions, and other cultural offerings. The temporary set-up of the event space in the drawing presents the possibility for the large urban street to host a multitude of cultural happenings at once in different areas of the streets.
The plastic barriers indicate that the transformation is temporary. The barriers stop traffic and can easily be installed or removed within a single day.
The temporary stage has the potential to be used for dance shows, concerts, theater performances and other events. The stage is less than 30 inches high and therefore does not require a handrail.
The portable toilets that are hidden behind the large screen constitute another temporary element of streetscape infrastructure.
Urban Street Before
AUG 10, 2020
The inflatable movie screen presents an example of a very short-term type of streetscape element. This movie theater would most likely only be in place for one night. Alternatively, a more permanent screen could be installed in the street for a series of movie showings over a longer span of time.
The string lights present a temporary source of lighting that can be installed and deinstalled within a short period of time. In addition, they can serve as decorative elements in an event space.
MANUAL OF PHYSICAL DISTANCING
P. 114
STREETSCAPES: Event Space Long-Term The long-term event space deploys a more permanent approach to the takeover of the urban street. New permanent streetscape elements include street lights, public restrooms, a large scale platform that can serve as stage, tables and seating. However, as the tables and chairs can be cleared out if necessary, the space remains flexible to host different types and different sizes of cultural events. The platform at the center of the former street intersection can be used as a place to meet, sit and chat when it is not used as a stage.
Urban Street Before
AUG 10, 2020
The new permanent stage facilitates the hosting of events in this large urban space. Bollards are installed at the entry to the plaza to prevent car access. The bollards are removable for emergency vehicle access and well as delivery trucks.
Though the new event space is a long-term and permanent solution, the space remains open to temporary, small-scale events such as art exhibitions.
The public restrooms present a large-scale infrastructural element that demonstrates the permanent nature of this transformation.
MANUAL OF PHYSICAL DISTANCING
P. 115
STREETSCAPES: Recreational Zone Short-Term The short-term recreational zone brings athletic elements such as basketball hoops and lightweight soccer goals into an urban context. The different sports are incorporated in the existing streetscape of this crosstown street: The soccer field is enclosed by a rectangle of crosswalks, the bus lanes determine the sidelines of the basketball court, and the existing street paint also shows the boundaries of the table tennis courts. The program recreational zone encourages movement and promotes health in the city.
Existing streetscape elements like kiosks, traffic lights, bike racks, etc. are maintained in this temporary transformation. The concrete barriers here indicate that the transformation is temporary. They provide a higher level of safety from car traffic than the plastic barriers.
Temporary play structures like basketball hoops and lightweight soccer goals can be brought onto the street for daytime play.
Existing street lanes are being used as guidelines for the boundaries of the table tennis court.
Urban Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 116
STREETSCAPES: Recreational Zone Long-Term The long-term recreational zone presents a full removal of the car and replaces the existing streetscape with a planar surface consisting of different types of paving to accommodate for the different sports that are being offered in this zone. In addition to basketball and table tennis, the permanent transformation also adds a field of chess boards to accommodate for different interests, age groups and degrees of mobility. The space also provides new seating opportunities through a series of benches along the chess boards as well as two-sided bleachers next to the basketball court.
A two-sided set of steps serves as bleachers for the basketball court but also enables people to turn the other way and observe the street life.
Bollards are installed at the entry to the plaza to prevent car access. The bollards are removable for emergency vehicle access and well as delivery trucks.
As opposed to the temporary recreational zone, the basketball court and hoops following the permanent transformation are embedded fully into the street surface.
The removal of the curb makes for an open street that allows pedestrians to diverge from the sidewalks and move freely through the space. In order to accommodate for different degrees of mobility, a set of chess boards provides opportunity for â&#x20AC;&#x153;mental athletics.â&#x20AC;?
Urban Street Before
AUG 10, 2020
The pavement has changed, the street lanes are gone and the mobile fold-out table tennis tables have been replaced by permanent durable tables that are cemented into the ground.
MANUAL OF PHYSICAL DISTANCING
P. 117
STREETSCAPES: Residential Street Typologies AUTOMOBILE In response to COVID-19, there has been a growing push in many cities to expand the public realm, specifically through the rapid short-term takeover of streets for various uses. The residential street typology presents a unique opportunity to develop possible new ways of creating public spaces and expanding the realm of the sidewalk for pedestrians and cyclists alike. The matrix presented here gives a variety of possible uses, both short and longterm transformations, of a residential street to give options based on timeline, scope and budget. It looks to show a few options that suggest a myriad of uses that might take place here.
PEDESTRIAN
typ. 1080 SF zone
typ.
1080 SF zone
37% 400 SF pedestrian 33% 360 SF parking 30% 320 SF automobile
38% 400 SF pedestrian 62% 680 SF open street *300 SF emergency vehic
typ.
1080 SF zone
100% 1080 SF pedestrian *300 SF emergency vehic
Play Street Conversion
Cool Street Conversion
Park Street Conversion AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 118
STREETSCAPES: Playstreet Short-Term The short-term playstreet builds off of existing playstreet typologies that already occur throughout many cities. In most cases, the street is closed down temporarily during daytime hours to thrutraffic to allow for more space for pedestrians, specifically children. Temporary play structures and games can be quickly deployed or implemented for easy transport and access.
Temporary play structures like basketball hoops and lightweight soccer goals can be brought onto the street for daytime play
Temporary barriers and cones at street entry to stop thru traffic and signify slow street
15 FT R EA
CL
Low cost play elements like cones and bars can be reworked to create simple games, obstacle courses or races to encourage movement
Fold out table and umbrella at entry to play street to provide space to pick up games, items and bagged lunches for children as well as provide some level of security for parents
Residential Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 119
STREETSCAPES: Playstreet Long-Term The long-term playstreet suggests a more wholistic and permanent solution to automobile removal on a small residential streetscape. Here, the street is removed and replaced with continuous paving throughout to create a plaza for pedestrians and bikers alike. More permanent bolllatds are put in place that can be removed for emergency vehicle access. Pockets of playground space, grass and interactive elements are introduced and built into the system to encourage active play and engagement of the area.
Entire street converted into continuous paving across block to allow one seemless plaza space for variety of activities and uses
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
Small grass zones near trees to provide shaded space for other leisure activities 15 FT R EA CL
Provide additional bike parking
More permanent play structures instaled that present a variety of types of play and interaction. Zones of turf or soft surface at play spaces to give a sense of location and containment
Residential Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 120
STREETSCAPES: Coolstreet Short-Term The temporary coolstreet is a typology that NYC is currently deploying throughout its streets in the summer months as a helpful solution for many communities that need additional respite from the heat. This temporary set-up presents cooling elements that are simple to assemble and install on site by accessing elements like fire hydrants, bringing hoses out for sprinklers, and installing temporary misting zones. Furniture can also be brought out to provide cool spaces to sit and interact outside of the home with shading devices like umbrellas.
Provide temporary furniture like umbrellas and cafe seating for outdoor socialization
Install spray caps on fire hydrants where permissible
Temporary barriers and cones at street entry to stop thru traffic and signify slow street
Encourage residents to bring out blow up pools, hoses and sprinklers for playful cooling of street 15 FT R EA CL
Install temporary misting zones with pipe and hook up to nearby water access
Residential Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 121
STREETSCAPES: Coolstreet Long-Term The long-term coolstreet deploys a more permanent approach to the takeover of the residential street. It suggests the removal of automobiles and replacement with continuous paving for pedestrians and bikers. Small pockets of cooling zones are embedded into the plaza with sprinklers, misters and fountains built-in. Additional foliage and large-scale canopies should be installed to provide maximum shading from the summer sun.
Entire street converted into continuous paving across block to allow one seamless plaza space for variety of activities and uses
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
15
Install fountains, sprinklers and water spray devices in a drainable zone for safe play and cooling
FT R EA
CL
Provide additional shading devices by planting more trees and installing large canopies overhead
Residential Street Before
AUG 10, 2020
MANUAL OF PHYSICAL DISTANCING
P. 122
STREETSCAPES: Park Short-Term
Provide planters and zones of grass at varying scales to encourage smaller interactions of different groups
The short-term park presents a temporary solution for more greenspace in an urban community that may have limited access to park space. By providing temporary pockets of roll-out grass zones for multiple groups of people to occupy, the park street provides a space for temporary respite from the city bustle. This type also looks to maintain a very clear bike lane through the street at all times. Small scale vendors and local artists presence are encouraged.
Temporary barriers and cones at street entry to stop thru traffic and signify slow street
Maintain bike lane access through street 15 FT R EA CL
Encourage presence of local street vendors for food and drink
Residential Street Before
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STREETSCAPES: Park Long-Term
Entire street converted into continuous paving across block to allow one seamless plaza space for variety of activities and uses
The long-term park case for the residential street presents a full removal of the car and replacement with continuous paving for the pedestrian. It also incorporates many zones of green space and grass lawns for various uses. More built in planters and benches are encouraged to provide additional seating and elements of privacy that start to create various pockets and zones of interaction.
Incorporate large scale planters and benches to provide additional seating, shading and foliage throughout park
Bollards installed at entry to plaza to prevent car access. Bollards are removable for emergency vehicle access
15 FT R EA CL
Provide planters and zones of grass at varying scales to encourage smaller interactions of different groups
Provide additional bike parking
Residential Street Before
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KIT OF PARTS Overview of Typologies Rethinking the existing streetscape, transforming occupation, program for temporary or permanent use can utilize existing infrastructural elements, ready-made elements, as well as simple DIY-parts. Slow-streets, playstreets, markets, commercial streets, bike traffic, and pedestrian areas in different parts of the urban environment require specific intervention. This is a brief overview of some of the elements and structures that are currently used and can be implied for the transformation of conventional car-centric streets into more pedestrian and bicycle uses of a street.
combination
recreation
cooling
vending
shading
signage and bike
lighting furniture barricade
paint
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KIT OF PARTS Barriers and Barricades Transforming streets into more bike and pedestrian focused areas requires the development of temporary, semi-permanent, and permanent solutions to divide the different kinds of traffic from each other and to designate certain areas for different uses and programs. Elements deriving from normal traffic control, to temporary barriers and more expensive constructed solutions offer the possibility of temporary organization, to more permanent solutions for the transformation of streets.
traffic cone
potted plant
garden fence AUG 10, 2020
belt stanchion
frame divider
traffic bump
traffic barrel
large planter
wood barrier
concrete jersey barrier
palette barrier MANUAL OF PHYSICAL DISTANCING
plastic barricade
concrete barrier
collapsible barrier
portable water-filled barrier
solid bollard
plywood barrier
steel barricade
traffic gate
planter barrier
large traffic sign
hydraulic bollards
barrier with screen P. 126
KIT OF PARTS Painted Patterns and Notations Symbols, lines, patterns and different color schemes can offer a variety of effects for a streetscape. Paint offers a cheap and fast transformation of a conventional street to alternative models, ranging from smaller generic symbols for traffic control, to simple patterns for slow-streets, to patterns covering the full street surface for playstreets and pedestrian areas.
6ft distancing pattern
6ft distancing pattern
6ft distancing pattern
large surface pattern - bike/pedestrian
large surface pattern - playspreed
distanced waiting marks traffic symbols and directions
distanced waiting lines
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games and play patterns
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KIT OF PARTS Furniture Street-furniture is a crucial part of the partial or complete use of existing streets for commercial and recreational purposes. The utilization of existing urban elements, temporary furniture for short periods or events, to more permanent solutions allow the street to change with its program and use.
plastic chairs
curb step
collapsible table
collapsible garden furniture
and stairs
picnic blanket
park bench
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table-chair set
outdoor bench
bench table set
outdoor bench with back support
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picnic table
car seat and hood
P. 128
KIT OF PARTS Lighting Clear marking of a slow-street or public plaza requires adequate lighting to enhance awareness of cars, and bikes, increase visibility, and create a more comfortable atmosphere. The different types of light-systems allow for cheap temporary changes as well as more expensive and permanent solutions, while supporting various uses and potential programs.
chain lights
chain lanterns
projector
construction light
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inflatable light
street light
park light
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solar-street light
walkway light
P. 129
KIT OF PARTS Shading The increased use of outdoor space requires additional protection from rain and direct sunlight for the different programs. These can range from umbrellas to larger tent structures and other more permanent options.
entrance canopy
shop canopy
tent
retractable awning
pergola
planted tree
fixed shading sun sail
beach umbrella garden umbrella
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KIT OF PARTS Signs and Bike Parking Structures around printed and digital information, as well as infrastructures for pedestrians and bikes are crucial elements for the safe and successful transformation of existing street scenarios. Expanding locking alternatives, city-bike stations, and bike pumps are important elements to increase the use of bikes, slow down the speed and amount of car traffic, while making the street more accessible for pedestrians. foldable sign
traffic reflectors
hand sanitizer
traffic sign
street sign
advertising pillar
electronic sign
bike pump
bike stands
bike racks
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stacking bike racks
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citybike station
P. 131
KIT OF PARTS Vending Applications Options for stores and markets allow safe interaction, transportation, and distribution of goods, utilizing existing structures, creating solutions for current modes of operations and creating new alternative ways of vending applications.
market stand
DIY - sales stand
market stand
newspaper boxes
book sales
pickup window
ticket dispenser
delivery bike
kiosk
drive-through
curbside-pickup
vending machine
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food cart
food truck
P. 132
KIT OF PARTS Recreation and Cooling Cooling and water play-structures in for the summer months can utilize existing infrastructures like fire-hydrants and garden hoses but can also be implemented into the street environment to generate a more permanent and designed structure.
fire hydrant
garden hose and sprinkler
sprinkler tiles
fountain
misting poles
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inflatable pool
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KIT OF PARTS Recreation Different play structures can be painted, deployed, occupying parking lots and parts of the road temporarily or permanently to generate a more community and family inclusive image of the street. Elements range from simple elements like hola-hoops and hopscotch, to designed play structures, allowing for multiple ways of exploration and play in a single setup.
swings
hoola hoop
seesaw
play structure
small goals hopscotch
four-square
table tennis
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basketball hoop
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KIT OF PARTS Combination Combinations of the previously shown elements allow configurations depending on program, specific requirements and budget for various situations, offering a kit of tools to transform existing streetscapes, sidewalks, parking spaces, and street corners into a more bike and pedestrian focused streetscape.
concrete barrier with screen
concrete barrier with pots
concrete barrier with planters
concrete barrier with large planter box
concrete barrier with large planter box, street sign, traffic reflector, and chain lantern
jersey barrier with screen
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jersey barrier with pots
jersey barrier with seating
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streetlights with chain barrier
park light with planter
P. 135
KIT OF PARTS Combination
roofed bike rack with digital screen
roofed bus stop with digital screen
seating with tent, concrete barrier and planter boxes
garden set with umbrealla
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market stand with tent and
simple market stand / outdoor
outdoor dining, with wood flooring, wood screens and dividers,
collapsable tables
shopping
sun sail, and jersey barrier MANUAL OF PHYSICAL DISTANCING
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URBAN SPACE CONDITIONS: PARKS + RECREATION
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PARKS: Urban Park and Green Space: Existing
Many New Yorkers lack private access to outdoor green space. The open lawns of public parks offer the opportunity for small groups to safely gather. Users can use such spaces in an informed way, being mindful of others nearby and refraining from activities that may violate social distancing, like team sports.
Shown: Madison Square Park, Manhattan
While the typical park bench can accommodate multiple users, these shared areas of repose do not intuitively indicate distancing practices.
High traffic areas like the threshold between sidewalks and park spaces can be difficult to navigate. They could be clearly marked with signage and include rules that should be observed for the safe use of the park.
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Some parks already have designated spaces for local food vendors. How might these dining areas be optimized to handle a higher volume of customers interested in enjoying their meal in fresh air.
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PARKS: Waterfront: Existing
Commuters are becoming increasingly reliant on alternative modes of transportation, like cycling and scooters. How might areas that already accommodate such modes of transpiration be models to other parts of the city that would benefit from multi-modal systems? How might cycling paths be better integrated with the existing infrastructure?
Shown: Pier 46 Hudson River Greenway
There are many benefits to recreation areas that share a close proximity to a body of water. How can New Yorkâ&#x20AC;&#x2122;s coastlines be optimized to be more available to the public?
Access to smaller riverfront parks can be high traffic areas dealing with pedestrian, cycling, and automobile traffic. How can these spaces best integrate different modes of transportation and remain safe for pedestrians?
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PARKS: Sports Fields: Existing
As many public, conditioned spaces like museums and theaters will be limiting their capacities to comply with social distancing practices, shade structures will become an increasingly valuable public resource to escape the heat of summer. How might existing structures be optimized to handle this change and how can additional shading devices be deployed in outdoor spaces?
Shown: Van Cortlandt Park, The Bronx
New Yorkâ&#x20AC;&#x2122;s largest parks have designated sports fields like baseball diamonds and soccer fields. Such areas are important for community engagement and outdoor recreation. How can sports that require less contact safely resume play?
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PARKS: NYCHA Green Space: Existing Shown: La Guardia Houses, Manhattan
Green space adjacent to public housing is typically unavailable for use. At a time when residents are confined to their place of living, how could these zones be optimized to provide ample outdoor space and fresh air for nearby residents?
Residents of higher occupancy buildings with limited access to private outdoor space could have prioritized usage of adjacent parks and other public outdoor space.
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PARKS: Plazas: Existing
As the use of larger office buildings will need to be adjusted to accommodate new practices, these plazas could assume a new role the process of entering and exiting the building.
Shown: Seagram Building Plaza
Over time hardscaping elements have been adapted as benches and places of seating. How might the same approach be used to convert some of the more barren characteristics of plazas into a more useful amenity?
Outdoor plazas common to business districts are a rare opportunity of public outdoor space in some of the cities most densely packed neighborhoods. These areas offer a break from nearby congested sidewalks and act as a buffer between building occupants and those simply passing by.
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PARKS: Playgrounds and Sports Courts: Existing Shown: Howard Houses Playground, Brooklyn
Sports courts offer ample outdoor space for residents seeking fresh air and are a critical component to community engagement. How might these spaces be altered to encourage the same interaction without the risks that come with contact sports? Is there a possibility that such open spaces could be used for other public activities like outdoor seating for food vendors or designated areas for religious practices?
Parks often have controlled points of entry and exit. How might signage at these thresholds indicate safe occupancy numbers and rules that should be followed while using such spaces? Play equipment has a high concentration of contact surfaces that could be transmitters of the virus between children. However, play is critically important to childhood development. How can play spaces be configured to anticipate the freeplay of children while balancing safety and transmission risk? Can the concentrated nature of play structures be distributed to anticipate and encourage separation while enticing creative play?
How might children be educated about social distancing practices and the benefits of frequent hand washing? Ensuring children are gathering with a consistent and monitored group could facilitate safe distancing practices in a school or daycare center.
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PARKS: Playgrounds and Sports Courts: Proposed Shown: Howard Houses Playground, Brooklyn • Signage clearly indicates entrances • Vendors who do not have the space to safely sell their products indoors can benefit from the outdoor air circulation • Vendors are set up with ample space for customers to navigate the market while practicing social distancing • Occupancy can be controlled at the gate and temperatures of all incoming customers can be taken
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PARKS: Large Green Space: Existing As other forms of sport and exercise have become limited, many are resorting to running and cycling. While many designated paths offer a place to do this safely they are not always free of crowds. How can these paths best be shared by walkers, runners, and bikers, and expand to be integrated with existing pedestrian infrastructure?
Shown: Prospect Park
Large green spaces in Central Park and Prospect Park perhaps offer one of the best opportunities for large numbers of people to safely enjoy outdoor space. While one of the most valuable characteristics of these spaces is their openness, how might users be educated to practice safe distancing etiquette while enjoying the spaces to their full potential?
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PARKS: Large Green Space: Proposed Shown: Prospect Park • Mobile projection screens and devices can be easily set up in outdoor environments • 2-4 person mats are arranged in a grid that keeps all patrons at a 6’ distance from one another • Outdoor theater would be able to accommodate up to 300 people • Provides an outdoor social activity that maintains safe distancing practices
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STREETSCAPES: Triangular Park Typologies AUTOMOBILE The matrix presented on this page gives on overview of the variety of potential programs for smaller triangular and infill parks that often represent underutilized spaces in New York City. Specifically, the drawings show Jackson Square Park in Greenwich Village, where the left column shows the park in its existing condition. The triangular park typology presents a unique opportunity to develop new kinds of pedestrianbased spaces out of already existing parks or plazas. The center and right column of the matrix show varying shorter and longer-term transformations, suggesting how the park might adapt to divergent programmatic uses and expand to repurpose less critical vehicular streets as pedestrian spaces.
PEDESTRIAN
typ. 1000 SF zone
typ. 1000 SF zone
typ. 1000 SF zone
26% 26% 10% 8% 30%
42% 20% 8% 30%
92% 920 SF pedestrian 8% 80 SF green space
260 260 100 80 300
SF SF SF SF SF
pedestrian automobile parking green space park/plaza
420 SF pedestrian 200 SF market stalls 80 SF green space 300 SF park/plaza *160 SF emergency vehicle
Marketplace Conversion
Event Space Conversion
Playground Conversion
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PARKS: Triangle Parks: Existing These smaller parks can offer a more immediate area of refuge from the surrounding bustle of the city, a useful characteristic where overcrowded sidewalks may present a hazard. They are often populated with benches and hardscape elements for seating and can include landscape elements or trees to provide shade on warmer days.
The irregular shape of these parks is often the byproduct of the intersection of higher traffic streets with historic and local circulation patterns. Given inefficiencies in the resulting vehicular flow, could these parks be better integrated with their adjacent neighborhoods and even strategically enlarged to expand pedestrian use and engage with multi-modal platforms like bike sharing and cycling paths?
In a network of hundreds of parks, New Yorkâ&#x20AC;&#x2122;s smaller triangular and infill parks can often be overshadowed by larger ones like Central Park and Prospect Park. How might these often underutilized spaces be made more useful and engaging for nearby residents?
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PARKS: Marketplace Short-Term Temporary barriers can easlily be installed or removed within a single day.
In this speculative short-term transformation, a market takes over a section of an adjacent street to create a temporary expansion of the public space of the park. The market vendors take over part of the vehicular and parking lanes to create to rows of market stands. This leaves enough space for pedestrians to walk freely in between the two rows as well as on the sidewalks on either side of the street. While the park retains itâ&#x20AC;&#x2122;s existing character, the resulting adjacency creates a symbiosis between a temporary use that enhances the public quality and utility of the Square.
Temporary market tents and stalls with minimal infrastructural needs can provide for flexiblilty of configuration, varying market types and durations of events.
The temporarily repurposed section of vehicular street is well connected to surrounding pedestrian circulation via crosswalks and sidewalks allowing for ease of access with minimum risk to users.
Triangle Park Before
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PARKS: Marketplace Long-Term In this long-term proposal, the triangle park is extended across the adjacent vehicular street to create a much larger plaza or park that takes advantage of reorgainzed traffic patterns and expands pedestrian space for civic uses. As opposed to the short-term solution, where the market occupies the street, the entire extended park can function as a market while maintaining its broader utility as a civic space. Like larger urban parks such as Union Square, the expanded triangle can accomodate recurrent patterns of public programming like seasonal markets that respond to increased need for outdoor commerce while remaining adaptable to shifiting uses. While the physical infrastructure of
The triangular park now extends over the full width of the previously vehicular adjoining street, recircuiting traffic flow and increasing pedestrian space and civic use. Paving and fencing is shown as an extension of existing materials and patterns, retaining the historic qualities and legibility of the
More permanent elements like fountains are replaced by more adaptable open space for pedestrians and cyclical market activity.
the market (tables, stands and stall) has not changed in comparison to the short-term transformation, the long-term transformation expands the boundares of the park to encompass the market or similar uses within its precinct.
Triangle Park Before
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PARKS: Event Space Short-Term Temporary barriers provide street closure and protection from vehicles on a rapidly deployable basis.
The triangular park as an event space can host a variety of contrasting noncommercial activities and cultural events. As in the previous example, the park retains itâ&#x20AC;&#x2122;s existing configuration while temporary elements are deployed to transform the street into a pedestrian venue that benefits from the parkâ&#x20AC;&#x2122;s adjacency. The enlongated proportion of the street could accommodate multiple uses, such as the combination of outdoor movie screeing and exhibition shown here, transplanting typically indoor programs into the open air. Temporary elements, like the inflatable movie screen shown here can provide for rapid short term programming at minimal cost while shifting indoor activities to more safely occupiable outdoor environments.
LIghting can provide a highly visible transformation of the streetscape to signal chnages in use and can be installed and deinstalled within a short period of time.
Triangle Park Before
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PARKS: Event Space Short-Term (ALT) In addition to specifically programmed cultural events, short term and rapidly implementable changes to streetscapes can also transform vehicular routes into more informal pedestrian spaces for local use. Simple but durable urban furniture can create casual seating areas, with graphic markings to entice social distancing or to designate activity zones. Here, street space is adjusted to accommodate cycling parking and bike share systems critical to a rethinking of urban networks in the face of increased pressures on public transportation.
Triangle Park Before
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PARKS: Event Space Long-Term
The triangular park now extends over the full width of the adjacent street, reclaiming it as pedestrian and civic space on a more permanent basis and allowing for greater flexibility of use for a variety of outdoor programming critical for public health.
The long-term event space deploys a more intensive approach to the expansion of the triangular park. New permanent elements such as street lights and public restrooms can provide for increased amenity, while a large-scale platform or stage, tables and seating can be installed in the space to accommodate shifting programming. in this way, the space remains flexible to host a variety of cultural events. Multi-use elements, like the large platform shown here, can be used as a place to meet, sit and chat on a day-to-day basis as well as a stage for choreograped performances.
The new platform can serve as a stage and turns the park into a open plaza that can host events, but also doubles as a space to meet, sit down and hang out.
The public restrooms present a more permanent infrastructural element that allows for greater utility of the park while providing a critical public amenity.
The provision of tables and chairs create new seating opportunities that allow for people to sit down and eat, rest, talk or people watch.
Though this long-term transformation deploys new permanent elements, the space remains open to temporary, small-scale events such as art exhibitions.
Triangle Park Before
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PARKS: Playground Short-Term Given the critical need for accessible and safe playgrounds in many areas of the city, these studies indicate the possiblity of transforming underutilized street space into temporary outdoor play spaces. The short-term play zone incorporates temporary play structures and low-cost elements to attract children and families to the site and to encourage outdoor physical activity vital to proper development and health in a safe and controlled environment. While historically urban streets have been appropriated for purposes of play on an ad hoc and unsanctioned basis, these drawings address the potential of fulfilling this very real need through the planned repurposing of vehicular and existing park spaces.
Temporary barriers provide for rapidly deployable street closure.
Low cost play elements can be reworked to create simple games, obstacle courses or to encourage movement.
Temporary play structures like basketball hoops and lightweight soccer goals can be brought onto the street for daytime play.
Triangle Park Before
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PARKS: Playground Long-Term The triangular park now extends over the full width of the adjacent street. As a space for children at play a more definitive barrier is required to ensure safety and controlled access from the sidewalk.
This illustration for a longer-term implementation of a playground foregoes the typical approach of arraying independent, single-use equipment like swings or jungle gyms since these classic elements imply safety issues and encourage the close proximity of children. Instead, the transformation shown here suggests a playscape comprised of only two elements: a modulated ground and a continous undulating bar. This kind of playstructure confronts children with new conditions for play, encourages creativity and invention and fosters interaction while allowing for more spatial distancing.
While the bar system and modulated ground surface of the playground create a dynamic condition in the center of the park that sparks creativity and play, the surrounding benches allow for parents to watch their children play from all sides of the enclosed triangle.
The trees and grass surfaces that comprise one aspect of the playground provide both a play surface and a shaded place on warmer days.
Triangle Park Before
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OTHER CONSIDERATIONS: Additional Proposals • Bring back awnings. Prior to the normalization of conditioned interior space, New York’s office buildings used passive strategies to control the indoor temperature. The same offices in use today often housed a larger number of workers and in the summer would use awnings and natural ventilation to maintain a comfortable working environment. This would allow for a greater exchange of clean air. • Wifi and power outlets in Parks? With coffee shops no longer being an option for an alternative work environment there may be the possibility of using controlled outdoor park space to provide an alternative. • Similarly, provide work pavilions/booths in parks to be able to work from a laptop in an outdoor environment.
Flatiron Building in the summer time (Circa 1910)
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URBAN SPACE CONDITIONS: PUBLIC TRANSPORTATION
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PUBLIC TRANSIT: Subway Concourse
Entry stairs could be marked to designate direction of movement or to coordinate directional circulation at larger multi-entrance stations.
Subways represent complex systems that involve infrastructural, operational and logistical challenges that exceed the parameters of this study. However, the choreography of subway users in relation to existing spatial conditions needs to be considered as an initial step in broader examination of urban space. Recognizing that significant alterations to physical infrastructure is unlikely to be feasible in the immediate future, behaviors and utilization patterns can adapt to better accommodate concerns regarding transmission and physical proximity.
Existing informational systems, both analog and digital should incorporate public messaging about prevention and encourage safe behaviors.
In the event the MTA deploys on demand rider services,a designated waiting area could be placed at the station entrance.
Shown: 57th Street Station
-0”
20’
Ticket kiosks and turnstiles represent high touch areas and additional risk of transmission. Passengers should minimize manual contact with surfaces passing through turnstiles.
Benches and waiting areas may need to be reconfigured and possibly enlarged where possible to encourage necessary spacing.
-0”
20’
Ground markings indicate the direction of travel on the stairs.
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-0”
20’
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PUBLIC TRANSIT: Subway Platform
Those waiting on the platform should provide ample space for exiting passengers to leave the train before they themselves attempt to board. This will prevent the direct contact that can occur in the close proximity of the train’s doors.
Shown: Jay Street MetroTech Station
Ground markings indicate the direction of travel on the stairs.
Benches and waiting areas can be reconfigured and possibly enlarged where possible to encourage necessary spacing.
Can existing physical components like paving patterns and columns serve as indicators for spatial distancing?
Pinch points at staircases represent specific challenges and should be avoided as waiting areas.
20’
-0”
20’
-0”
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Platforms that service both express and local lines will need to accommodate larger crowds and a more complex circulation of transferring passengers. Riders should be mindful of these platforms that are prone to crowding and congestion.
P. 159
PUBLIC TRANSIT: Subway Interior
Passengers should observe distancing protocols by leaving space between themselves and others, even forgoing a train if it appears to be at capacity.
Shown: Typical Subway Car
Like street furniture on sidewalks, columns set up natural patterns of stasis along the platform edges in distinction to zones of movement toward the center. Subway users should avoid walking in front of waiting passengers in these congested zones.
One possible boarding strategy would involve passengers using the train’s middle doors to enter and doors closer to the ends to exit.
Existing digital kiosks could incorporate information regarding scheduling and safety procedures to help minimize overcrowding and promote beneficial behaviors.
Consideration should be given to adapting and possibly expanding benches at platforms for greater spatial distancing.
20’
-0”
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS, QUEENS
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS Introduction
St t s
Residential Area
Jackson Heights in Queens, NY is one of the most culturally and ethnically diverse areas of the country. The small stores and restaurants that typify this diverse area has been especially hardhit by the Covid-19 closures and rules. In response, the Urban Design Forum and Van Alen Institute launched Neighborhoods Now to channel pro-bono resources from New York-based design firms into community-driven recovery strategies, including working with the 82nd Street Partnership in Queens. The design strategies are focused on using the public space of the street and sidewalk in new, more equitable ways, to expand the public use of the shared spaces of the city to address Covid-19 challenges. These strategies include connecting businesses with the NYC Department of Transportationâ&#x20AC;&#x2122;s Open Streets programs.
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The 82nd Street Partnership area
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https://www.vanalen.org/projects/neighborhoods-now/
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https://www1.nyc.gov/html/dot/html/pedestrians/openstreets.shtml
82nd Street, near Roosevelt Avenue, is the location of the annual Viva La Comida, which closes the streets to traffic to create a community festival celebrating the diverse culinary cultures of the neighborhood.
While most of the area is residential, commercial areas are concentrated near larger Roosevelt Avenue and Northern Boulevard.
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In addition to the local pedestrian traffic from a largely residential area, 82nd Street receives pedestrian traffic from one of Roosevelt Avenueâ&#x20AC;&#x2122;s subway stations.
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ev
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The Jackson Heights neighborhood is located in Queens, near Elmhurst.
Commercial Area
tA ve
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS Current Condition In its current condition, 82nd Street south of Roosevelt Ave and the 7 train is home to a number of local restaurants and businesses. The sidewalks are typically quite full of local residents and customers who come to shop the diverse cultural and culinary offerings of this area, many by car, others by subway that stops at the 82nd Street station. There is limited space on the sidewalks, with space already used by street vendors and carts. The street is slow owing to heavy used by delivery vehicles, cars seeking parking, and buses.
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54.6% of the street programed for use by automotive vehicles, 15.4% of the paved area of the street is dedicated to parking spots and bus stops, while 39.2% is dedicated to vehicular traffic
Currently, less than half (45.6%) of the street is devoted to pedestrian uses, through sidewalks, rest areas, and bus stop seating.
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS Open Restaurants Adaptations With the closure of interior commercial spaces to meet Covid-19 social distancing guidelines and New York City and State rules, restaurants cannot as of Summer 2020 use the interior space to serve customers at tables. The NYC Department of Transportation initiated the Open Restaurants program which allows restaurants the opportunity to seek and obtain a permit to use select areas of streets as temporary outdoor dining. This program has very clear rules for utilization of public space of sidewalks and streets, but does provide a mechanism for reconsidering how streets can be used to serve businesses and the public in addition to supporting the storage of private automobiles.
Restaurants can seek to use select areas of sidewalks for outdoor table seating in front of their business.
Restaurants can seek to use select areas of streets for outdoor table seating in front of their business.
Outdoor seating is not allowed to be placed in front of bus stops among other restrictions and designations.
https://www1.nyc.gov/html/dot/html/pedestrians/openrestaurantsfaq.shtml
This is an example of outdoor seating that is allowed, with barriers required to provide a designated boundary, a ramp to meet accessibility rules, and tables set to meet required dimensional regulations.
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS Hypothetical Use of Street for a Wide Range of Public Uses The public need to remain socially distant and to remain outside creates a need and opportunity to creatively use the public space of the city, of which streets are a large component. However, the current DOT Open Restaurants program does not include other commercial businesses or public uses. This drawing illustrates a possible expansion of the logic of the Open Restaurants program to include a wider range of commercial and public uses. In this illustration, public seating, expansion of commercial businesses and translation areas are located in the side parking lanes of 82nd street, significantly expanding the usable public space of this area to meet the changes posed by living with Covid-19.
Open Restaurant program allows these businesses to utilize select areas of streets for outdoor seating.
Expanding the use of parking spaces for other functions could include sitting areas, commercial stores, shade areas, and other public amenities.
Benches, bicycle racks, and canopies could transform areas currently occupied by parked cars, creating a more pedestrian-friendly street with more diverse activities.
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CASE STUDY: 82ND STREET, JACKSON HEIGHTS Open Streets Proposal
Canopies act as shade structures providing cover from the sun and light rain.
The NYC DOT created the Open Streets Program to allow community groups to petition for closing streets for designated times to automotive traffic, thus making streets open space for pedestrians and cyclists. As part of the Neighborhoods Now program, the 82nd Street Partnership petitioned with the aid of a consortium of architecture firms, to transform this portion of 82nd Street into a Open Street for weekends. NYC has the goal of opening 100 miles of Open Streets. https://www1.nyc.gov/html/dot/html/pedestrians/openstreets.shtml
Streets are closed to automotive traffic, allowing safe use by a wider number of pedestrians and cyclists.
Commercial and public use of the streets is enabled so long as they meet rules and regulations of the program.
Vehicular bollards and barriers protect the street. A 15-foot wide fire access must be maintained. AUG 10, 2020
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P. 166
CASE STUDY: 82ND STREET, JACKSON HEIGHTS Hypothetical Pedestrian Street Transformation Transitions of the street, like those effected by the BID in the Open Streets program, may ultimately demonstrate the value of having an entirely pedestrian street. In this vision of 82nd street, the street is permanently pedestrian, albeit with delivery and emergency vehicle access, and stores have designated outdoor vending spaces. Other amenities like the triangle park and the public realm for pedestrians are increased significantly.
As the street is only open to delivery vehicles during designated times, pedestrian safety increases and there is significantly more room for public use of civic space. Ithaca Street, a short side connection, could be transitioned into a park expansion, giving more space to the public realm for play and leisure activities.
Outdoor vending spaces are provided for businesses equivalent to their street frontage with a separation of 6 feet to each neighboring business.
Vehicular bollards and barriers protect the street. A 15 foot wide fire access must be maintained. AUG 10, 2020
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P. 167
CASE STUDY: 82ND STREET, JACKSON HEIGHTS Open Restaurants Adaptations The NYC Department of Transportation oversees the administration and rules for the Open Restaurants and Open Streets Programs. These regulations include dimensional requirements and boundaries to meet compliance. A few of the key rules are outlined in this diagram. The DOT continues to update its rules to meet the nature of this dynamic program to meet the constant social and political changes wrought by Covid-19.
Seating must be at least 15-feet from a fire hydrant.
8
” -’ 0
15
’-0
”
https://www1.nyc.gov/html/dot/html/pedestrians/openrestaurantsfaq.shtml
”
-0
8’
Clear passage of 8-feet must be maintained from sidewalk restaurant seating to curb.
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Seating cannot extend more than 8-feet from the curb.
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CYCLING INFRASTRUCTURE
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CYCLING INFRASTRUCTURE Global Rapid Deployment to address Covid-19
The Covid-19 pandemic has witnessed an interesting array of approaches to expanding cycling infrastructure throughout the globe. The following is an abbreviated selection from 4 continents.
Cities around the world have created temporary and/or permanent cycleways in response to providing greater access to the public space of streets for bikes. Traveling by bike in the open air is safe and an important means of combating congestion and pollution associated with a spike in the use of private automobiles, and decline of the use of public transportation systems.
City
Population
Size of Proposed Temporary Routes 187 miles
Facility Type
Barrier Type
10,719,188
Size of Existing Bike Network 78 miles
Lima
Protected Bike Lanes and On-Street Bike Lane
Traffic Cones, Painted Road, Barriers
Paris
2,148,000
430 miles
93 miles
Protected Bike Lane and On-Street Bike Lane
Traffic Beacons, Painted Road Surface Sign
Oakland
433,031
164 miles
74 miles
Shared Use Path
Traffic Cones, Signs, and Road Barriers
Bogota
7,413,000
340 miles
47 miles
Protected Bike Lanes
Traffic Cones
Santiago
6,767,223
33 miles
36 miles
On-street Bike Lane, Protected Bike Lanes
Painted Road Surface Sign, Divider Barriers, Flexible Posts
Budapest
1,764,000
202 miles
22 miles
On-Street Bike Lane
Painted Road Surface Sign
Vancouver
2,436,967
279 miles
19.8 miles
On-Street Bike Lane w/ reduced speed limits
Traffic Cones, Signs, Road Barriers
London
8,982,000
72 miles
18.6 miles
Protected Bike Lane and Shared Use Path
Wands, Road Barriers
Vitoria
362,097
22 miles
8 miles
Signs, Barriers, Painted Lanes
Sydney
4,925,987
34 miles
4.7 miles
On-Street Bike Lane w/ reduced speed limits, Protected Bike lanes Protected Bike Lanes and On-Street Bike Lane
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Painted Road Surface Sign, Divider Barriers, Flexible Posts
P. 170
CYCLING INFRASTRUCTURE Types of Rapid Response Cycleways
Creating cycling infrastructure to accommodate and encourage the increase of cycling can be done through a series of design tactics. These range from simple graphic markings to more durable physical barriers.
The following is an index of different strategies that can be used when implementing a cycleway as a rapid response to COVID-19. Different strategies may depend on budget, size constraints or speed limits of adjacent vehicular traffic. Rapid responses can be designed to comply with best practices so they may become permanent segments in long-term cycling networks.
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Shared Street
Painted Stripe
Ground Signage
Painted Lane + Ground Signage
Fully-painted Lane
Painted Lane + Signage
Traffic Cones
Ground Signage + Traffic Cones
Plastic Posts
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CYCLING INFRASTRUCTURE Types of Rapid Response Cycleways
Creating cycling infrastructure to accommodate and encourage the increase of cycling can be done through a series of design tactics. These range from simple graphic markings to more durable physical barriers.
The different strategies can be combined to best suit the needs of the cycleway. This index has been organized in terms of least protection from vehicular traffic to most protection from vehicular traffic
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Ground Signage + Plastic Posts
Reflective Stripe
Barricade
Concrete Ballards
Painted Stripe + Signage
Painted Lane + Road Guard
Road Guards
Concrete Barriers
Jersey Barriers
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CYCLING INFRASTRUCTURE Best Practices Based on Speed The Copenhagenize Bicycle Planning Guide, authored by Mikael ColvilleAndersen, establishes a clear guideline for different types of bike pathways. Each of these bike pathway designs is tied to car speed as a critical measure for determining which design to adopt to ensure safety.
When implementing temporary or rapid-response cycling infrastructure, its important to abide by best practices for cycling infrastructure. The practices, outlined by The Copenhagenize Bicycle Planning Guide align design to road speed as a key criteria to ensure safety in either temporary or permanent designs.
http://www.copenhagenize.com/2013/04/the-copenhagenize-bicycle-planning-guide.html
0 to 25 mph
25 to 29 mph
Shared use of street using graphics if necessary to indicated mutual use
Designated bike lane through graphic demarcation
http://www.copenhagenize. com/2013/04/the-copenhagenize-bicycle-planning-guide.html
30 to 44 mph
45 to 75 mph
Separated bike lane, defined by a raised curb, median, or barrier
Fully separated bike lane, isolated from roadway by physical and land barrer AUG 10, 2020
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CYCLING INFRASTRUCTURE Best Practices: 0 to 24 mph Shared Streets On slow residential streets where there is limited traffic and speeds are below 25mph, streets can be designated for shared use of the same space. Here, cyclists and automobiles move at roughly the same rate and the speed of traffic is slow enough to anticipate sharing the street. This designation is typically used where there is very low volume of vehicular traffic.
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Care needs to be taken at intersections where crossing streets with higher speeds and greater volumes of traffic.
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CYCLING INFRASTRUCTURE Best Practices: 25 to 29 mph Designated Lane On streets where the allowable speed is above 25mph, cyclists need to be given a designated path of travel. This is best located on the right hand side of the road adjacent to the sidewalk. A parked car zone should not be placed between the bike lane and the sidewalk. If a parking zone is on the same side as the bike lane, a designed buffer must be placed between the bike land and parked car area to account for the opening of car doors.
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The designated bike path should be adjacent to the sidewalk. Car parking should ideally be separated from the bike lane.
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CYCLING INFRASTRUCTURE Best Practices: 30 to 44 mph Separated Lane When the speed exceeds 30mph and the volume of vehicular traffic increases, bike lanes need to have hard separations from car and truck traffic. These designations can be curb, barrier and/or physical space. Space for door swings should always be accommodated if a parking zone is adjacent to the bike path. Separation should also be made between the bike path and the pedestrian sidewalk.
Careful attention must be paid to crossings, especially turning vehicles that cross cycle lanes.
Pedestrians, cyclists and vehicular traffic need to be given independent and safe means of travel which minimize any overlaps and crossings.
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CYCLING INFRASTRUCTURE Best Practices: 45 to 75 mph Isolated and Protected Lane Where speeds exceed 45mph and volume of traffic increase, bike lanes need to be physically isolated and completely separate from the street. Barriers and separations need to be designed to safely protect cyclists from potential automotive accidents. Bike lanes adjacent to highways are often designed in a similar manner to be cycling highways for connecting between locations. Bi-directional bike lanes are most workable on bike highways where travel over long distances mitigates possible overlaps and crossings between the two sides.
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P. 177
CYCLING INFRASTRUCTURE RPA’s Five Borough Bikeway for New York City, 2020 The Regional Plan Association of New York unveiled in June 2020 a new cycling plan for the region, “The Five Borough Bikeway”. This plan, spurred on by the changes needed to address the transportation realities of addressing Covid-19, outlines a city-wide arterial bike network of 425miles of continuous, protected bike lanes that provides the primary means of cycling throughout the city. This plan argues for a rapid expansion of dedicated and safe cycling paths that can serve as the infrastructural backbone to tie and link all boroughs. As the RPA notes, “start implementing temporary parts of the Bikeway as part of the COVID-19 recovery, and in the longer term, create a task force to develop a broader city-wide vision for a connected, high-capacity Bikeway. The task force should focus on streamlining the public outreach and construction process and attracting new cyclists of all ages, genders, races, and incomes.”
Union Square Intersection of E 14th Street, 4th Ave to Park Avenue and 17th Street
For this manual, we have identified a couple of key intersections to examine how rapidly deployed changes to expand cycling to meet Covid-19 challenges could align with implementing this future vision of a city-wide permanent network. These design recommendations look to integrate in the current, albeit patchwork, system of bike lanes while anticipating this city-wide infrastructural network. https://rpa.org/work/reports/the-five-borough-bikeway
Grand Army Plaza Intersection of Flatbush Ave, Eastern Parkway, Prospect Park West, and Plaza St East
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CYCLING INFRASTRUCTURE Union Square, Manhattan Union Square in as a central crossing of significant north-south and east-west streets, including a break in the continuous passage of Broadway. The current cycling pathway systems around and past Union Square is fragmented and disjointed. 14th Street was recently converted into a dedicated bus street. The RPAâ&#x20AC;&#x2122;s 5 Borough Bike Plan anticipates utilizing 14th Street as a bike corridor and creates the opportunity to reconsider the entire cycling infrastructure around Union Square.
East 17th Street and Park Avenue East 15th Street and Union Square East
Subsequent pages show the existing condition, propose rapid-response (covid-19) deployment changes and possible permanent designs to align with the RPAâ&#x20AC;&#x2122;s plan.
East 14th Street and Broadway
East 14th Street and 4th Avenue
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RPA plan existing bike paths
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CYCLING INFRASTRUCTURE Union Square, Manhattan: Current Condition
ay dw
St
oa
5th
[PROBLEM] There are bus stops on both sides of this street.
Br
E1
[PROBLEM] There is a bus stop further down this curb with a Citibike station across.
4th A ve
The intersection of 14th Street, 4th Avenue and Broadway is a difficult triangle. The current bike systems is fragmented at this location and puts cyclists in the hazardous position of having to cross over traffic lanes on both north and south routes to follow bike paths. The two-way bike path on the east side of Union Square which creates significant conflicts on both ends, exemplifies why two-way bike lanes on one side of a street is most often a poor design choice.
[NOTE] This bike lane on the left side is part of a multi-block long dedicated bike path.
E1
4th
[PROBLEM] The two-way bike path on the East side of the park terminates without being integrated into the overall bike network.
[PROBLEM] There are no bike lanes on 14th Street.
ast
eE
on
Uni
ar Squ
[PROBLEM] There is no direct, clear connection between bike system parts.
existing
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St
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CYCLING INFRASTRUCTURE Union Square, Manhattan: Rapid Response
ay dw
St
oa
5th
[SUGGESTION] With bus stops on both sides of the street, use pavement markings or signs to symbolize shared lanes.
Br
E1
[SUGGESTION] Create a bike lane adjacent to the Citibike station that runs down Broadway.
4th A ve
The following design recommendation look to improve this key intersection through using rapid response infrastructural measures. These changes can help move more cyclists through this important intersection and take advantage of the reduced traffic on 14th Street to make it a central east-west bike path to meet Covid-19 bike traffic needs.
[SUGGESTION] Paint a clear bike box on the end to allow for right hand turns onto 14th Street.
E1
4th
[SUGGESTION] Use cones and paint to make Park Avenue a bike lane the length of the Avenue north. existing new
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n nio
U
ast
Squ
E are
[SUGGESTION] Extend the bike lane with cones on the east side of the park to connect to 14th street. MANUAL OF PHYSICAL DISTANCING
[SUGGESTION] Paint a bike box to allow bikes to move from right side to left side of road on red-light.
St
[SUGGESTION] Implement separated bike lanes where possible on 14th Street. Coordinate with bus stops.
P. 181
CYCLING INFRASTRUCTURE Union Square, Manhattan: Permanent Change
[SUGGESTION] Install a timed bike traffic light for cyclists to cross from left to right side as 4th Ave becomes Park Avenue.
ay dw
St
oa
5th
[SUGGESTION] Transform 14th street to accommodate both bus and cycling as independent systems that avoid overlaps.
Br
E1
4th A ve
The rapid-response changes made with paint, cones and signs should align with longer-term permanent solutions. In this diagram, properly design bike paths are shown, consistent with the overall RPA 5 Borough Bikeway.
E1
4th
[SUGGESTION] Turn Park Ave bike lane into a dedicated, protected path up the avenue, to align with the RPA masterplan.
t
n nio
U existing new
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as re E
a
Squ
[SUGGESTION] Continue these buffered lanes along 14th Street and consider constructing bus boarding islands at bus stops.
[SUGGESTION] Change the existing two-way lane into a one-way lane.
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St
[SUGGESTION] Install a timed bike traffic light for cyclists to cross from right to left side of Broadway.
P. 182
CYCLING INFRASTRUCTURE Union Square, Manhattan: Current Condition The corner of 17th and Park Avenue is currently the location of a two-way bike path that turns. This is a point of confusion for pedestrians and an opportunity for reconsideration. Two-way bike paths in the middle of a network of connections creates more problems than it solves. When the path ends, one lane is inevitably on the wrong side of the street and thus creates a problem in creating a bicycling seamless system.
[PROBLEM] The two-way bike path is at a key pedestrian intersection and plaza, home to the Union Square Farmersâ&#x20AC;&#x2122; Market.
ue
ven rk A
Pa
E1
7th
St
existing
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CYCLING INFRASTRUCTURE Union Square, Manhattan: Rapid Response This proposal looks to use paint and cones to turn Park Avenue into a bike way with separate lanes on each side of the avenue. This change, along with providing a bike path on 17th would help elevate the challenges of navigating Union Square and connection north-south bike travel on Park Avenue with east-west travel on 14th Street.
[SUGGESTION] Use cones or posts to demarcate rapid changes to road users.
[SUGGESTION] Create a one-way lane along E 17th Street and a bike box for bikes turning left.
[SUGGESTION] Create a lane connection. Consider using signs to ensure cyclists on the two-way lane yield to those coming down from Park Avenue.
[SUGGESTION] Create Covid-19 rapid response bike lanes on both sides of Park Avenue.
ue
ven rk A
Pa
E1
7th
St
existing new AUG 10, 2020
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P. 184
CYCLING INFRASTRUCTURE Union Square, Manhattan: Permanent Change The rapid-response proposal would serve as the basis for this permanent implementation of a city-wide bike system and aligns with the goals outlined by the RPA.
[SUGGESTION] Provide a clear physical separation for cyclists from traffic using a raised curb or barrier.
[SUGGESTION] Change twoway path into a one-way path going east and then south. This will allow cyclists going down Broadway to go around Union Square smoothly.
[SUGGESTION] The transformation of Park Avenue into a north-south artery is key part of the RPAâ&#x20AC;&#x2122;s plan.
existing new AUG 10, 2020
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P. 185
CYCLING INFRASTRUCTURE Grand Army Plaza, Brooklyn Grand Army Plaza in Brooklyn is a confluence of major traffic, pedestrian and cycling routes. At the north entrance to Prospect Park, this intersection is currently a difficult point of connection for the existing cycling paths that go around the Plaza, connect into the park, extend down Eastern Parkway, and Prospect Park West. A proposed bikeway down Flatbush Avenue will add to the complexity.
Eastern Parkway and Grand Army Plaza
Subsequent pages show the existing condition, propose rapid-response (covid-19) deployment changes and possible permanent designs to align with the RPAâ&#x20AC;&#x2122;s plan.
Existing Cycling Lanes Cycling Lane Proposed
Prospect Park West and Grand Army Plaza Flatbush Avenue and Grand Army Plaza
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CYCLING INFRASTRUCTURE Grand Army Plaza, Brooklyn: Current Condition The north entrance to Prospect Park is at the main intersection of Grand Army Plaza loop and the the sequence of main roads that connect to this loop. The cycling path currently is fragmented and confusing to riders and pedestrians.
[PROBLEM] The two-way path around Grand Army Plaza is incomplete.
[PROBLEM] There are no bike lanes along Flatbush Avenue.
[PROBLEM] Access to the heavily used Prospect Park Bike crosses the pedestrian plaza.
[PROBLEM] The two-way bike path on Prospect Park West is confusing and creates problems at intersections and connections at its ends.
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P. 187
CYCLING INFRASTRUCTURE Grand Army Plaza, Brooklyn: Rapid Response A rapid response approach to Grand Army Plaza can help improve this area while providing connection to areas of Brooklyn served by Flatbush Avenue. These changes can be done by adjusting how Flatbush avenue is used, providing bike lanes instead of parking for private cars, and using graphic markers and cones to organize travel through the pedestrian plaza.
[SUGGESTION] Create one-way buffered bike lanes along Flatbush Avenue on both sides using cones or other rapid-response measures.
[SUGGESTION] Use cones to designate a clear bike path at the edge of the pedestrian plaza to allow connection.
[SUGGESTION] Use graphics to extend bike path to Prospect Park to the connection path.
[SUGGESTION] Use graphics to extend bike path on Prospect Park West to the connection path.
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P. 188
CYCLING INFRASTRUCTURE Grand Army Plaza, Brooklyn: Permanent Change An important part of making a city wide cycling system work is turning Grand Army Plaza into an intersection that is seamless for cyclists, pedestrians and vehicles. Rapid response changes can be used as the foundation for a permanent improvement to this key aspect of Brooklyn transport.
[SUGGESTION] Install dedicated curb-protected bike lanes on both sized of Flatbush Avenue.
[SUGGESTION] Complete the two-way ring around Grand Army Plaza complete with timed lights.
[SUGGESTION] Use permanent graphics to extend bike path to Prospect Park to the connection path.
[SUGGESTION] Split the twoway bike path into bike paths on both sides of Prospect Park West to clarify flow.
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HISTORY OF PANDEMICS: IMPACTS ON ARCHITECTURE AND CITIES
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HISTORY OF PANDEMICS Introduction Since the early stages of civilization and the domestication of livestock some 10,000 years ago, epidemics have posed an ever present risk to humanity. When such deadly disease outbreaks escalate to the scale of a pandemic, they often disrupt societal structures and elicit collective responses to cope with significant loss of life and prevent future impacts. Disease outbreaks have therefore shaped the development of human settlements in profound and varied ways, often in correlation to factors such as contagiousness, duration of infection, and means of transmission. Given the inherent relation of urban space to processes of contagion, epidemics and pandemics have had a pronounced impact on cities in particular, influencing the development of supply logistics, the exchange of goods, spaces of social gathering, sanitation systems and hydrological infrastructures, the regulation of dwellings, and the evolution of specific building typologies. While a comprehensive cataloging of these conditions is beyond the scope of this Manual, we have selected a few illustrative examples: the bubonic plague, cholera, smallpox, tuberculosis and polio, to demonstrate the intersection between pandemic events and the spatial organization of cities.
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HISTORY OF PANDEMICS Timeline
Charting pandemics over time not only reveals the longevity with which some persisted but also the apparent increasing frequency of outbreaks during the last century, While this increase is in part attributable to increased knowledge of and detection of disease processes, factors like population growth, increasing density of cities and the impacts of climate change and globalization strongly suggest that pandemics will continue to pose a threat for the foreseeable future. Historically, the illnesses which have prompted the most evident spatial changes are often those lasting many decades or even centuries such as smallpox, cholera, tuberculosis and polio. For this reason the examples that follow focus on these diseases.
1300
1400
1500
1600
1700
1800
1900
2000
Pandemic Black Death Smallpox 17th Century Great Plagues 18th Century Great Plagues
Fatalities 1347
75M-200M
1351
1520
3M
1700
1600
1700
600K
1800
Cholera
1817
The Third Plague
1M+
1975
1855
Tuberculosis
12M
1940s
1.5M
1800s
Yellow Fever
200K
1880s
Russian Flu
1889
Polio
1M+
1890
1894
Spanish Flu (H1N1)
50M
1919
1957
Hong Kong Flu (H3N2)
1.1M
1958
1968
HIV/AIDS
10M+
1995
1918
Asian Flu (H5N1)
1M
1970
25M-35M
1981
SARS
2002
Swine Flu
2003
2009
MERS
2010
2014
COVID 19
2019
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770 200K 850
2012
Ebola
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56M
1980
2016
11.3K 586K
P. 192
HISTORY OF PANDEMICS Contagiousness and Deadliness Not Very
Contagious
Very
Other factors that determine the impact of a pandemic are its rate of transmission and its deadliness after infection. Though these two metrics are mutually exclusive, they both contribute to the pervasive nature of pandemics and the fatalities they incur. The higher fatalities of black death are likely attributed to its relatively high deadliness and the higher fatality rates of smallpox are likely related to its high degree of contagiousness. However, these findings exclude outside factors that cause certain diseases to have a greater impact. For example, the outbreak of the Spanish Flu being simultaneous with World War I meant that larger gatherings of people and increased world travel contributed to greater transmission of the disease.
Highly
Fatalities
Mortality Rate
Contagiousness
Black Death 75M-200M
HIV/AIDS 80%
Polio 6
Smallpox 56M
Ebola 70%
Smallpox 5.9
Spanish Flu (H1N1) 50M
Tuberculosis 68%
COVID 19 5.7
HIV/AIDS 25-35M
Black Death 60%
Tuberculosis 5.5
Polio 10M+
Asian Flu (H5N1) 60%
HIV/AIDS 3.5
Tuberculosis 1.5M
MERS 45%
Spanish Flu (H1N1) 3
Asian Flu (H5N1) 1.1M
Polio 22%
Yellow Fever 3
Cholera 1M+
Smallpox 16%
Ebola 2.5
COVID 19 586K
SARS 9.60%
SARS 2.4
Swine Flu 200K
Yellow Fever 7%
Cholera 2.1
Yellow Fever 200K
COVID 19 4.3%
Swine Flu 1.5
Ebola 11.3K
Spanish Flu (H1N1) 2.5%
Black Death 1
Unlucky / Unhealthy
MERS 850
Cholera 1.63%
Asian Flu (H5N1) 1
Not Too Deadly
SARS 770
Swine Flu 0.20%
MERS 0.5
100%
90% HIV/AIDS 25M-35M
80%
Extremely Deadly
Ebola
Tuberculosis
11.3K
70%
Death Likely
1.5M
Asian Flu Case Fatality Rate
Deadliness
1.1M
60% Black Death 75M-200M
50%
MERS
40%
850
Deadly
High Chance
30%
Polio 10M+
20%
Smallpox 56M
SARS
Yellow Fever
770
10%
Quite Deadly
200K
Cholera
COVID 19
Spanish Flu
1M+
586K
50M
0%
High Risk Groups
Swine Flu 200K
0
1
2
3
4
5
6
7
8
9
10
Contagiousness
No. of people one person will likely infect
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HISTORY OF PANDEMIC Transmission, Symptoms, and Duration
Pandemic
Transmission Method
Incubation Period 25
Flea bites and contact with contaminated fluid or tissues of an infected mammal
Perhaps one of the greatest contributing factors influencing spatial responses to pandemics has been the duration of the illness itself for an individual and the length of time for recovery. Illnesses like smallpox, polio and tuberculosis involve recovery periods lasting up to several months. As a result permanent, purpose built sanitariums were designed and constructed to isolate infected populations or to provide a more salubrious environment outside of cities where people could recover from chronic illnesses. These buildings coincided with a broader preoccupation with health and hygiene that characterized contemporaneous examples of modern architecture, evidenced by open plans, plentiful natural ventilation and modern materials and finishes that could be readily sanitized.
20
15
10
Symptoms 5
0
Days
Recovery Period 0
5
10
15
20
Spatial / Architectural Response 25
30
Fever, headache, chills, one or more swollen lymph nodes
Lazarettos, Elevated buildings for rat-proofing
Human-to-human via fluid in sores or airborne droplets
Fever, body aches, pustular rashes and sores
Smallpox hospitals, Quarantine stations
Consumption of contaminated food and water
Diarrhea, vomiting, muscle cramps, and dehydration
Water infrastructure, Quarantine Stations
Polio
Human-to-human via airborne droplets or feces
Flu-like, paresthesia, meningitis, and paralysis
Spanish Flu
Human-to-human through airborne droplets
Fever and pains all over the body
Tuberculosis
Human-to-human via airborne droplets
Fever, chest pains, coughing blood or phlegm
Sanatoriums
Contact with infected animals and human-tohuman via bodily fluids or secretions
Fever, pains, fatigue, diarrhea, hemorrhaging, and bruising
Personal Protective Equipment (PPE) guidelines, Ebola Treatment Centers
Black Death
Smallpox
Cholera
Ebola
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Polio hospitals
Open-air treatment facilities, parks and public spaces
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BUBONIC PLAGUE: 15TH CENTURY Venetian Lagoon Trade & Quarantine The Bubonic Plague devastated large portions of Europe over a period of several years, ravaging populations. Given Venice’s dependence on trade for it’s power and prosperity, it developed a system for quarantining people and goods, isolating possible agents of transmissions prior to admission to the port. These spaces of containment took the form of the lazaretto’s, control points within a network of trade routes that allowed Venice to remain buffered from the worst impacts of the Plague.
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Once cleared, people and goods were allowed entrance into Venice.
Lazzaretto Vecchio Lazzaretto Nuovo These islands acted as the first prophylactic layers protecting Venice from the plague. Usually ships known to carry the plague were docked at Lazzaretto Vecchio while those suspected of coming from ports that had contact with the plague docked at the Lazzaretto Nuovo.
Trade with the Venetian hinterlands was not subject to quarantine. This is because public health measures could be taken closer to the point of contact such as near borders with other city states and empires.
Outgoing trade from Venice was not subjected to quarantine measures in Venice but rather at the incoming port. Internal trade from Venice to Chiogga (not shown) in the southern tip of the lagoon was not subject to quarantine in lazzarettos.
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BUBONIC PLAGUE: 15TH CENTURY Island of Lazzaretto Vecchio Landing places provide access to the island. On this edge, the docks inject goods straight into the warehouses where they would be stored.
The port city of Venice was at the forefront of pandemic responses to the plague. This island, just off of the Venice Lido, was the first-ever hospital dedicated solely to the isolation and treatment of plague-infected people. Between 1423 and 1630, the Lazzaretto housed infected Venetians or maritime travelers from outside of the region. Goods and patients would stay on the island for a minimum of 40 days, before being allowed to enter the city (the word quarantine is derived from the Italian word for 40, Quaranta). The island was later used in combination with the Lazzaretto Nuovo which was established in 1468.
A burial ground was also present on the island. The high fatality rate of the plague meant that masses of people were buried on the island.
Lazzaretto Vecchio was separated from the nearby Lido which serves as a boundary to the Venice lagoon. Plague-stricken Venetians and passengers from outside of Venice were isolated and treated in apartments on the island.
The majority of space in this lazzaretto was dedicated to the storage of goods that were cleaned before storage, usually by fumigation (shown in light grey)
Merchant ships transporting goods and passengers from outside of Venice were required to dock at the Lazzaretto before gaining admission to the city.
There were other facilities on the island such as a church, gunpowder magazines, and a wax cellar. Before becoming a quarantine station, the island was a monastery. This adjacent island was initially built to house the prior and his gardens.
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BUBONIC PLAGUE: 15TH CENTURY Island of Lazzaretto Vecchio Originally converted from a monastery, the Lazzaretto Vecchio was the first quarantine facility of its kind, established in 1423. Ceremonial spaces and monk’s quarters were repurposed as living quarters for passengers and crew during their 40 days of quarantine while the addition of long, narrow store houses held cargo and other goods. This model of isolated quarantine would persist for more than five centuries in the Mediterranean region and become a standard practice for other mercantile cities.
Individual suites were used to house a ship’s crew. These were largely found along the existing monastery compound.
The Prior’s house overlooked the main courtyard and occupied a strategic position on the site along the south-west corner where it had a vantage point on incoming ships.
Goods would be efficiently stacked and stored in warehouses. Entrance could take place either where the ship was docked or via a small canal with an entrance leading to the main courtyard. Though goods had a number of ports of entry, all people came in though the main courtyard. Trade vessels would dock and disembark, their crew and goods on hold for forty days.
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BUBONIC PLAGUE: 15TH CENTURY Island of Lazzaretto Nuovo The Lazzaretto Nuovo is located in the north-east of the lagoon and was established in 1468 as an addition to the Lazzaretto Vecchio. Its main purpose was to relieve and distribute the amount of quarantined ships in the “old” Lazzaretto, and primarily focused on housing crews of sailors and infected Venetians. The principles of the Lazzaretto became an important element of the fortification of harbor cities around Italy and would inform the basic strategies of quarantine hospitals for later pandemics.
One hundred rooms for sailors and potentially infected Venetians were organized within the fortification wall of the island.
The largest structure of the Lazzaretto Nuovo is the main storage building. All goods needed to be washed, aired, or fumigated before getting stored in this structure. Fresh goods and supplies would be delivered ‘contactless’ through openings and windows on the back of the facility.
Incoming merchant ships where known for bringing the plague to the mainland. They would need to anchor their ship for the time of the quarantine, before receiving a ‘passaporto’ allowing the crew to enter the city.
Separate parts of the structure entailed the prior’s quarters, food and supply storage for the facility, wells, a church, a kitchen, and two gun powder towers.
The Deceased were buried in the graveyard on the island, to avoid potential infection and transportation of disease to the city.
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BUBONIC PLAGUE: 15TH CENTURY Island of Lazzaretto Nuovo Goods coming from merchant ships would be kept in large storage halls in the center of the island while passengers and crew stayed in designated quarters along the perimeter. During quarantine, tenants were allowed move freely about the island along courtyards that stretched between the long storehouses. However, breaking quarantine early was a crime punishable by death.
Merchantâ&#x20AC;&#x2122;s quarters were located on the outer perimeter of the lazzaretto, with windows facing only the courtyards. The ground floor accommodated a fireplace as well as sitting and washing areas. Upstairs would be a bed and place to keep personal belongings.
The large courtyards were used to air-out goods that were unable to be washed, or fumigated. These spaces provided exposure to sunlight and fresh air.
Fresh goods and supplies were delivered through openings and windows on the back side of the facility, away from the quarantined sailors.
The courtyard facing porticoes of the lazaretto allowed the prior and plague doctor to access every patient regardless of weather conditions.
Packages and goods were checked, cleaned, and stored in the large storage halls in the center of the lazzaretto.
Food supplies and kitchens were accessible through courtyards not used for the storage of potentially infected goods.
Storm water drainage would be collected through gutters and feed wells in the courtyards.
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BUBONIC PLAGUE: ADAPTATION 20th Century Army Storehouse
Buildings were to be spread 10’ apart, and freestanding on at least three sides.
By the late 1800s the bacteriological nature of the plague was well understood, however episodes persisted well into the 20th century in the United States including the 1900 plague outbreak in San Francisco, the 1914 episode in New Orleans, and the 1924 events in Chicago and Los Angeles. At this time most methods of prevention focused on solutions to rat infestations, since rat’s had been identified as a primary vector for transmission, a condition unknown to the Venetians during the time of the Lazzaretto’s. So prevalent were these concerns of rat-borne illnesses that even the 1940 Army Manual of Preventative Medicine provided detailed specifications for the construction of ration storehouses that ensured protection from small rodents. These examples illustrate both the persistence of diseases across historical periods and the ways in which shifting understanding of infectious processes influenced physical space.
A brick area wall of 6” thickness and over 1’ high would prevent rats from burrowing in the gap wall.
Wooden posts were to be sheathed with tin or lead, preventing rodents from burrowing in the frame.
Buildings were to be lifted 18” on brick or concrete piers, enough to allow dogs and cats to hunt down rodents.
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CHOLERA: 1832 NEW YORK OUTBREAK Water Infrastructure Network
After the saturation of the local water supply, the need for a reliable source of freshwater forced City authorities to implement extensive infrastructural works to address the issue. The Old Croton Aqueduct, connecting the Croton River in Westchester County with Manhattan reservoirs, served the city from the later 1840s to 1955.
Originally identified in the early 19th century in the Ganges River Delta, cholera is spread through the consumption of water contaminated with human and animal waste. During the ensuing centuries, outbreaks have been registered all over the world, the latest ones recorded in Somalia and Yemen in 2017, and in Haiti in 2010. The disease is associated with improper sanitation practices often caused by a lack of clean fresh water supply or inadequate sewage disposal. Efforts to control the disease are concentrated in the establishment of sanitation apparatus. In New York City, cholera outbreaks in 1832 and 1849 affected dense neighborhoods like the Lower East Side and resulted in some of the first State-led urban infrastructure initiatives such as the construction of a city-wide sewer system and aqueducts.
A combined sewer system, which collects both storm and wastewater through the same pipe, is present in about 60% of New York City. Under normal conditions, this water flow is directed to a treatment plant. However, heavy rainstorms create higher flows in the system, and lead to wastewater to being discharged directly into the cityâ&#x20AC;&#x2122;s waterways.
The Old Croton Aqueduct carried water by gravity for over 40 miles, as shown in the topography lines in relationship to the aqueduct section. The fresh water was critical to mitigate the spread of cholera and vital to the future growth of New York City.
The Croton Aqueduct entered the city by traveling over the High Bridge at 173 street and was brought to the Receiving Reservoir, located in what is now the Great Lawn of Central Park. The aqueduct was critical for improved water quality throughout the length of Manhattan including previously disease prone neighborhoods like the Lower East Side. Lower East Side, Southern Manhattan
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CHOLERA: 1832 NEW YORK OUTBREAK Before and After Urban Sanitation Cholera was first recorded in North America in 1830, in Quebec City and Montreal, and it is believed to have spread to New York City through the newly opened Erie Canal. By 1832 the City had one of the worst cholera outbreaks in history. The disease hit hardest in poorer, densely populated neighborhoods, particularly the slum known as Five Points. Located in what is today the Lower East Side/Chinatown area, its residents were mostly AfricanAmericans and immigrant Irish Catholics, who upon getting sick, were treated as castaways for their race and socioeconomic status. Improvements in water supply and waste disposal practices, combined with subsequent regulation of tenement buildings for improved ventilation and sanitation comprised a concerted municipal response to the outbreak with long term impacts to public health and broader benefits to the city.
Outhouses were a common sanitation practice, but the accumulation and consequent disposal of waste in nearby waterways contaminated the water supply.
The presence of livestock in the City, particularly pigs, was a common practice until the earlier half of the 19th century. Consistent disease outbreaks loosely connected with bacteria spread by livestock led City authorities to ban pigs from the most urban parts of Manhattan by 1849.
Tenement buildings, then the main typology of dense collective living in the city, were mandated to feature individual Water Closets (WCâ&#x20AC;&#x2122;s) connected to the larger sewer network after the Housing Act of 1867.
Paved streets and the collection of stormwater into the city-wide sewer system ended the practice of street washing, which previously directed wastewater into the soil and contaminated the supply accessed through private wells.
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CHOLERA: 1832 NEW YORK OUTBREAK Innovations on Distribution and Disposal Housing conditions in densely populated areas often did not provide appropriate sanitation, making them prone to the spread of the cholera bacteria. In 1867, regulations were imposed on some of these neighborhoods by the â&#x20AC;&#x153;Act for the Regulation of Tenement and Lodging-Houses in the Cities of New York and Brooklynâ&#x20AC;?. The policy act ruled on a number of design features for housing, including private bathrooms, fire escapes, underground occupation and maximum density for residential areas.
Fire escapes were among the improvements that came along with the Tenement Act that shaped the facades of New York City.
Modern water sourcing and sewage systems allowed for a constant supply of clean water for drinking and hygiene.
Water Towers were needed in buildings over 5 stories tall to maintain proper water pressure.
Fire hydrants connect to the main water line.
The Housing Act of 1867 demanded that sleeping units would be connected to a direct source of ventilation. Building shafts were adopted as a strategy to allow housing complexes to be more densely occupied while complying with the new rules.
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Storm drains collect stormwater to be disposed to treatment plants. MANUAL OF PHYSICAL DISTANCING
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SMALLPOX AND POLIO: ROOSEVELT ISLAND Quarantine Islands in New York Harbor New Yorkâ&#x20AC;&#x2122;s harbor has presented a unique case study for disease containment over the course of many pandemics and disease outbreaks. For many of the most serious outbreaks, quarantine islands dispersed around the greater harbor of New York housed a variety of suffering patients at different points in time allowing for the isolation, containment and treatment of infected populations directly adjacent to the density of the city. Roosevelt Island became one of the most prominent of these islands due to its unique proximity to Manhattan and its development over time to produce a variety of government-led efforts to quell the spread of infectious diseases, like smallpox. The island further became a center for welfare reform and rehabilitation, specifically with polio patients in the early 20th century.
Hart Island 1877 Yellow Fever
Brother Islands 1850 Smallpox 1943 Tuberculosis
Roosevelt Island 1856 Smallpox 1939 Polio
Swinburne and Hoffman Islands 1890 Cholera and Typhus
Ellis Island 1911 Measles, Scarlet Fever, and Diphtheria. *All other more extreme cases were sent to Swinburne and Hoffman Islands
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SMALLPOX AND POLIO: ROOSEVELT ISLAND Quarantine and Treatment Centers Formerly Blackwell Island, then Welfare Island, and now Roosevelt Island, this land mass situated between Manhattanâ&#x20AC;&#x2122;s Upper East Side and Queens, was a hub for various institutions dealing with health, welfare and containment. Most notably, during the smallpox outbreaks of the late 19th century, the island housed patients in quarantine in the Renwick Hospital on the southernmost tip of the island. The island was renamed to Welfare Island in the early 20th century during a wave of public health reform. The Welfare Hospital for Chronic Disease opened in 1939 to aid in long term treatment and rehabilitation for polio patients during the major New York outbreaks of the 30s-50s along with other chronic illnesses. Access to the island was limited until the opening of the Roosevelt Island Bridge in 1955.
Roosevelt Island Bridge opened in 1955 and provided vehicular access to the island
Renwick Hospital opened in 1856 as a quarantine hospital for patients in the greater NY area who were suffering from Smallpox during the outbreaks of the late 19th century. It was in operation until 1886, after which it was converted to a nursing school. The remains of the hospital are now a landmark on the existing island.
New York City ca. 1930
Queensboro Bridge connects New York City to Queens at 59th St and opened in 1909. It passes over Roosevelt Island but did not provide vehicular access directly until 1930 when an elevator was built to transport cars down to the island.
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Goldwater Memorial Hospital opened in 1939 during the wave of welfare reform occurring throughout New York City and became a center for care of chronic illnesses and focused on Polio treatment and rehabilitation during the outbreaks of the early 20th century.
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SMALLPOX AND POLIO: ROOSEVELT ISLAND Quarantine and Rehabilitation Hospitals The southern tip of Roosevelt Island housed both the Smallpox Hospital for quarantine in the 1860s as well as the Goldwater Memorial Hospital from 1939. Both prompted a level of development and access to this island from prisons and workhouses housing to nursing dormitories, and fire stations. During the push for public health reform in the early 20th century the Welfare Hospital for Chronic Illness was just one of the many hospitals and facilities developed on the island to provide government funded aid, research and welfare.
The Smallpox Hospital opened in 1856 and was the first hospital in the US to receive patients with smallpox. By law, all city residents who contracted the disease had to quarantine on the island
Goldwater Memorial Hospital was a center to handle patients with chronic illnesses. At that time, Polio outbreaks were prevalent in the summer months in New York whereby this hospital became central to their rehabilitation and treatment.
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SMALLPOX AND POLIO: ROOSEVELT ISLAND 1939 Welfare Hospital for Chronic Disease
Service entry for nursing staff, doctors and administration was located on the opposite side of the administrative building
The Welfare Hospital for Chronic Disease was designed by architect, Isadore Rosenfield with a focus on what then was believed to be the restorative ability of buildings to provide curative forces of light and air. It opened in 1939 to aid in long term treatment and rehabilitation for polio patients during the major New York outbreaks of the 30s-50s along with other chronic illnesses. It remained functioning as a care facility up until 2013 when it was demolished to make room for the new Cornell Tech Campus and its patients relocated to the hospitalâ&#x20AC;&#x2122;s sister facility on the northern tip of the island.
The angle of the chevron-shaped wards were calibrated to the sun and water to maximize access to light and air as well as waterfront views
The primary corridor connected each patient wing respectively with the main administrative building which housed rehabilitation specific and treatment rooms as well as dining services. The unique configuration of the complex meant that this connective passageway, necessary to link the distributed buildings, became itâ&#x20AC;&#x2122;s own distinct architecture: building as pure circulation.
The main entry to the hospital was at the center of the administrative building where patients would then be distributed to one of the four chevron-shaped wings based on their illness, need and ambulatory level
Visitor access was at the two points off of the primary corridor that connects all wings
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SMALLPOX AND POLIO: ROOSEVELT ISLAND Polio Treatment and Rehabilitation Goldwater Memorial Hospital was one of the first to focus its efforts not only on long term care and rehabilitation of patients but pioneered barrierfree elements like ramps, low height surfaces, and wider doors. It provided a haven of access and independent movement for those disabled by illness like polio as well as veterans or those with long-term illnesses. The building became an important precursor to subsequent implementation of accessibility principles beyond the doors of health care facilities.
A single main corridor connected each patient wing respectively with the main administrative building which housed rehabilitation specific treatment rooms as well as dining services.
The northern half of the ward buildings were devoted to servicebased spaces such as bathrooms, labs, storage and offices.
Barrier-free elements like ramps, low height surfaces and wider doors were a major consideration in providing access to the grounds of the island
Balconies provided access to natural light and air within the patient wards. The overhang between floors was carefully calibrated to manage both the angle of the harsh summer sun and allow the winter sun to pass through
All patient wards were located along the southern face in order to optimize access to natural light and air
A large porch-like pavilion space on the main level of the wards enabled a hard-surface gathering space for the patients and guests outdoors.
Day room solariums were for leisure and interaction between patients as well as for families and visitors
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TUBERCULOSIS: SANATORIUM ZONNESTRAAL Map of Hilversum, Netherlands Outbreaks of Tuberculosis (TB) have had a persistent presence in modern times, characterized by its high contagiousness and often long duration of recovery. Quarantining infected patients was an integral part in combating the spread of this illness in order to reduce its impact. One method of isolation, beginning in the late 19th century, was to place TB patients in sanatoriums: housing that provided healthy eating and outdoor living to those infected with Tuberculosis. A new building typology at its conception, it focused on fresh air circulation, exposure to sunlight, and immersion in nature. The Zonnestraal Sanatorium in Hilversum, Netherlands was built in 1931 by Jan Duiker and is a prime example of one such institution. Its facilities were designed to optimize patientsâ&#x20AC;&#x2122; health and present an example of how specific architectural solutions, often isolated from urban centers, emerged to isolate and address chronic diseases like tuberculosis.
Hilversum proper.
A gate marked the entrance of the sanatorium at the border of city and forest, well before reaching the actual buildings of the sanatorium. This prevented people from haphazardly entering the complex, and marked a point of beginning to the quarantine.
Sanatorium Zonnestraal is located outside of the city limits without being too far removed, being accessible to the town for necessary supplies. The estate is immersed in nature and able to keep patients isolated to prevent the spread of illness.
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TUBERCULOSIS: SANATORIUM ZONNESTRAAL The Zonnestraal Campus Tuberculosis was an infectious disease associated with poor working conditions. A source of income to help TB-affected workers was the sale of the copper stems, a waste product in the diamond industry. In 1905, the Copper Stealing Fund (KSF) was established for this purpose. In 1919, the KSF purchased the 116-hectare Pampahoeve estate in the Loosdrecht woods near Hilversum for the foundation of a self-sufficient labor and aftercare colony for TB patients. The isolated location outside of the city was favorable not only for preventing the spread of the disease but also for curative reasons. The Sanatorium Zonnestraal opened in 1928. Apart from medical and residential facilities, the campus included workshops which enabled patients to work during their extended stay. In this sense, the Sanatorium comprised not only an isolated medical facility but a more comprehensive communal environment for the restoration of health in a secluded natural setting.
Patients were allowed to be up for short, and gradually longer, periods of time throughout the day. They were permitted to walk around the premises and spend a few hours a day in workshops. The workshops allowed patients to maintain, develop, and improve their professional skills while recovering from the illness.
The residential pavilions featured four wings that consisted of long strips of single patient bedrooms, each with south facing terraces. These pavilions were oriented such that each room had unobstructed views of the forest. The connecting buildings featured conversation rooms and lounges as well as dining facilities for the patients.
The main building housed the general facilities of the complex, including a large recreation room, a section for medical facilities, research and operating rooms, infirmary, central kitchen, administration and directorâ&#x20AC;&#x2122;s suite.
The secluded domes housed the servants and nurses of the sanatorium.
The wooden villa was the only existing building on the Pampahoeve estate when the Copper Stealing Fund purchased the land to built a sanatorium in 1919.
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TUBERCULOSIS: SANATORIUM ZONNESTRAAL Residential Pavilion The facilityâ&#x20AC;&#x2122;s residential pavilions featured four wings that consisted of long strips of single patient bedrooms, each with south facing terraces. The building relied on a relatively modern floor plan with a single loaded corridor and a unit measurement of 1.50 m. It featured a long strip of 3x3 m single patient bedrooms with 1.50 m terraces on the south side. The 1.50 m corridor on the north side connected the bedrooms to the sanitary facilities. At the time, sunlight, air and nature were considered to be therapeutic treatments for TB patients. Therefore, all residential wings were oriented south for maximum exposure to sunlight. The sanatorium emphasizes a close connection with nature. The sanatorium emphasizes exposure to natural elements coincident with the medical beliefs of the time but also architectural qualities of transparency, structural expression and spatial continuity consistent with prevailing modernist princples. In this way, the Sanatorium and buildings like it demonstrate the exchange between a specific spatial response to disease and broader shifts within architectural discourse and practice.
Each bedroom was furnished with a patient bed, a little shelf, desk and chair and a movable lounge chair. In addition, each room featured a sink next to the door.
The overhang created by roof and balcony prevented the glass facade from overheating.
The movable lounge chairs were made out of lightweight bamboo for ease of movement and allowed for patients to rest outside in the sun during the daytime.
Each bedroom had individual access to the large terraces facing south, guaranteeing maximum sun exposure for the patients. The transition from interior to exterior space is minimal and demonstrates a closeness to nature.
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The thin steal frames of the glass facade reveal the temporary nature of the original building. The complex was built as a transitory facility under the expectation that a cure for tuberculosis would be found within the next 30 to 50 years. MANUAL OF PHYSICAL DISTANCING
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