Parking

00 00 00

07:30 07:00 00 06:30

04:00

04:30

05:00

05:30

00 06:00 00 00 00 00 00 00 03:30

02:30

00 03:00 00 00

02:00 01:30

Turning

01:00

Bypassing

Cruising Cruising

00:30

Visitor

21 Left 20 Left

17 Left

18 Left

19 Left

Northeastern University School of Architecture ARCH G691 Graduate Degree Project Studio

16 Left

et 00:00

3 Left

24 Left

25 Left

26 Left

27 Left

29 Left 28 Left

FALL 2008

23 Left 22 Left

+30’-0”

2 Left

1 Left 0 Left

Familiar

PARKING 15 Left 14 Left 13 Left 12 Left 11 Left

9 Left 8 Left 7 Left 6 Left 5 Left 4 Left 3 Left 2 Left

Relative MPH

+10’-0”

1 Left

+10’-0”

10 Left

+20’-0”

85

85%

+40’-0”

FALL 2008

PARKING Northeastern University School of Architecture ARCH G691 Graduate Degree Project Studio

MARIA BABYAK

CHRISTOPHER GODFREY

ALETA BUDD

BRITTANY LEVINE

CAVIN COSTELLO

MICHAEL PRATTICO

CHRISTOPHER CROCKER

BRIDGETTE TREADO

JUSTIN DICRISTOFALO

JOSEPH YACOBELLIS

Introduction 1 Fundamentals

18’-0”

1.1 Basic Dimensions

96”

2 Types 8’-0”

S

A

Two Way Single Helix

B

Central Two Way

C

One Way Double Helix

D

Split Level

E

Express Ramp

3 Planning and Design 3.1 Structure 3.2 Enclosure Strategies 3.3 Economics 3.4 Ground Floor Planning 3.5 Pedestrian Access

PLANNING AND DESIGN

90°

types

1.3 Accessibility

1.4 Level of Service

fundamentals

1.2 Stall Layouts

3.6 User Behavior

Sources

SOURCES

8’-0”

INTROdUCTION

arc G69 1 t y p o l og y pat t e r n b o o k

Introduction

Parking Garage: Introduction

fundamentals

INTRODUCTION

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

The scope of this study has been carefully defined

Considering the pragmatic nature of parking

to consider only multi-storied structured parking

structures,

garages

ramping

Structural capacities, dimensional limitations,

technologies as a means of moving vehicles.

and occupational demands can be calculated to

Single-storied structures and surface lots have

define the most efficient structure for any given

been exluded, along with structures employing

site. Parking garages are therefore valued less

mechanical lifts as a method conveying vehicles.

for the aesthetic qualities, and more so for their

While surface lots and mechanical lifts are both

economic and programatic efficiencies.

utilize

traditional

their

success

is

quanifiable. types

which

The purpose of this book is to define the essential

circulation as will be explored throughout this

design criteria for architects conceptualizing new

guide.

parking

structures.

There

exists

in

the

marketplace a broad spectrum of parking design Structured parking is a unique building typology.

literature, from general graphic references to

Unlike typical buildings, parking structures exist to

detailed specifications.

satisfy a singular need: to efficiently store a large

middle ground, an appropriately comprehensive

number of vehicles in the smallest space possible.

guidebook for architectural designers. This book

With population growing and urban centers

is that middle ground.

becoming continuously more congested, the demand for more efficient parking solutions is exponential.

What is missing is a

SOURCES

the fundamental issues of ramping and pedestrian

PLANNING AND DESIGN

viable solutions to parking, they do not address

Fundamentals

The following chapter of information will include the basic information for parking garage layouts, such as, parking stall sizes, drive aisle dimensions, height restrictions, turning radii, and ramp dimensions. Further information regarding accessible parking and level of service are also included

PLANNING AND DESIGN

types

fundamentals

INTROdUCTION

Parking Garage: Fundamentals

within this chapter. The chapters following the fundamentals chapter will probe further into the design criteria required to successfully develop a structured parking garage. Local codes and zoning

codes

information.

must

be

consulted

for

further

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

” ’-6 IN M 24’

-0”

1.1

Basic Dimensions

Height & Parking Stall Size

Turning Radius: Flat & On-Ramp Parking

Figure 1.1.1 Height Clearance

Single Lane Minimum Turning Radius in Parking Area

18’-0”

7’-0”

fundamentals

R

Standard minimum clear height of a parking level

Figure 1.1.3 Single Lane Turning Radius

Figure 1.1.4 Two Lane Turning Radius

from finish floor to finished ceiling shall be 7’-0”.

Bottom of structure, finishes, and infrastructure

8’-2”

” ’-6 14 IN M

types

rest of this chapter for further requirements.

Figure 1.1.2 Parking Stall Size

24’

-0”

24’

R

R

’-6

”

6” CLEAR

13

9’-0”

24’-0 ”

18’-0”

PLANNING AND DESIGN

-0”

SOURCES

” ’6 26 IN M

9’-0”

must not project below 7’-0” clear. Refer to the

Standard stall sizes are 9’-0” wide and 18’-0” in depth. Local zoning codes and level of service

Standard minimum single lane turning radius for

SingleorLane Minimum flat surfaces on-ramp parking areas is 24’-0”

Standard minimum two lane turning radius for flat

Two Lane Minimum Turning Radius in the outside turning Area radius. The minimum clear disParking surfaces or on-ramp parking areas is 24’-0” for

(LOS) determine parking stall dimensions and

Radius in The minimum clear for theTurning outside turning radius.

must be consulted. Back up requirements as well

distance for a single lane single direction is 14’-6”.

as orientation must be taken into consideration

Refer to parking layouts in this section for mini-

to parking layouts in this section for minimum

when laying out parking stalls. Refer to the rest of

mum dimensions regarding back up conditions,

dimensions regarding back up conditions, and

this chapter for further information.

and ramp slopes for required minimum slopes for

ramp slopes for required minimum slopes for on

on ramp parking. See Figure 1.3

ramp parking. See Figure 1.4

Parking Area

tance for a two lane single direction is 26’-6”.Refer

” ’6 26 I M

Turning Radius: Non-Parking Ramps

Figure 1.1.5 Minimum Single Lane Radius

’-6

”

24’-0

”

6” CLEAR

Standard minimum clearance for a vehicle’s turning radius on a non-parking ramp is 13’-6” clear.

fundamentals

8’-2”

1.1 Basic Dimensions 9’-0”

INTROdUCTION

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

13

The outside turning radius must me a minimum 24’-0”. A minimum clearance of 6” is required to any obstruction along the outside minimum radius.

types

See Figure 1.1.5

Standard minimum clearance for a two lane vehi-

’-0

”

6” clear with an additional 12’-0” clear as the

36

13’-6 ”

cle’s turning radius on a non-parking ramp is 13’passing lane. The outside dimension of the radius must be a minimum 36’-0”. A minimum clearance of 6” is required to any obstruction along the outside minimum radius. See Figure 1.1.6

SOURCES

12’-0 ”

6” CLEAR

PLANNING AND DESIGN

Image 1.1.6 Minimum Two Lane Radius

fundamentals

INTROdUCTION

1 SLOPE:20 5% MAX (2% CROSS SLOPE) SLOPE: 5% MAX (2% CROSS SLOPE)

Ramping Ramps with a max slope of 12% can be a maxi-

30’-0” MAX

Figure 1.1.7 Non-Parking Ramp with Pedestrian Circulation 30’-0” MAX

mum of 30’-0” in length and are not considered an

1 8.3331

accessible route for pedestrians with disabilities.

Refer to Figure 1.1.9 Ramping Transitions for

SLOPE: 12%1MAX 8.3331 (30’-0” MAX LENGTH)

ramps over a 10% slope and coordinate with turning radius dimensions where turning occurs on ramping. See Figure 1.1.7. For ramp information

SLOPE: 12% MAX (30’-0” MAX LENGTH)

regarding on-ramp parking refer to section 1.3 Accessible Parking. types

Image 1.1.8 Non-Parking Ramp without Pedestrian Circulation Ramps with a max slope of 15% have no constraint to a maximum distance, however, are not considered an accessible route for pedestrians.

Refer to Figure 1.1.9 Ramping Transitions for

1 6.6665

PLANNING AND DESIGN

ramps over a 10% slope and coordinate with turning radius dimensions where turning occurs on

SLOPE: 15%1MAX 6.6665

ramping. See Figure 1.1.8. For ramp information regarding on-ramp parking refer to section 1.3

SLOPE: 15% MAX

Accessible Parking.

Image 1.1.9 Ramping Transitions Where a difference in slope of 10% or more occurs

SOURCES

between two sections of surface, a transition

10’-0” 10’-0”

slope is required. A transition slope of 1/2 the slope difference must be provided. See Figure 1.1.9

10’-0” 10’-0”

fundamentals types PLANNING AND DESIGN

1.1 Basic Dimensions

INTROdUCTION

Parking Garage: Fundamentals

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

0° (Parallel)

45°

60°

60°

Standard single loaded parking configurations are

types

parking) angles. 30° layouts are typical, however

0° (Parallel)

45°

Parking Stall Layout: Minimum Dimensions typically arranged at 45°, 60°, 75°, 90°, 0° (parallel

20’-0” 12’-0” 8’-0”

Stall Layouts

30’-1” 11’-0” 19’-1”

1.2

37’-0” 17’-0” 20’-0”

INTROdUCTION fundamentals

100’-0”

not efficient and therefore not shown. 5° increments between 45° and 90° are also possible for non-typical conditions. Refer to Table 1.2.2 for and car types.

Parallel parking conditions are

non-typical conditions, but are shown for compari-

The parking layouts in Figure 1.2.1 describes a minimum dimension situation for five types of parking angles.

75°

One way traffic patterns are

shown. Double loaded parking configurations are possible and more typical than single loaded configurations.

A minimum of 22’-0” is required for

aisle ways where two way traffic is present and SOURCES

75°

23-0”-24’-0” is allows for safe pedestrian circulation in drive aisles.

Figure 1.2.1 Minimum Stall Layout (right)

90°

41’’-0 23’-0” 18’-0”

PLANNING AND DESIGN

son to other angled parking types.

40’-5” 21’-0” 19’-5”

specific dimensions which factor in turnover rates

90°

1.2 Stall Layouts

INTROdUCTION

Parking Garage: Fundamentals

PLANNING AND DESIGN

types

fundamentals

Table 1.2.2 Minimum Dimension Area Calcs

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

vice. Refer to Tables 1.2.5 and 1.2.6 for more variable sizes regarding stall orientations shown

20’-0” 12’-0” 8’-0”

45°

30’-1” 11’-0” 19’-1”

W2 AW VPw

ing depth and overall width relate to level of ser-

W2 VPw

Variable dimensions for drive aisles, vehicle park-

0° (Parallel)

AW

INTROdUCTION fundamentals

Parking Stall Layout: Variable Dimensions

be used in large area layouts with many different stall orientations (45° Parking is shown). Refer to Table 1.2.5 and 1.2.6 for more information.

VPw W2

90° AW

lock type layout, which is not typical, however can

40’-5” 21’-0” 19’-5”

W2 VPw

75°

AW

W4

types PLANNING AND DESIGN

One other possible parking stall layout is the interSOURCES

60° AW

Figure 1.2.4 Interlock Parking Layout

W2

Figure 1.2.3 Variable Stall Layout (right)

41’’-0 23’-0” 18’-0”

VPw

shown.

37’-0” 17’-0” 20’-0”

in Figure 1.2.3 and more orientation options not

INTROdUCTION fundamentals types

1.2 Stall Layouts

PLANNING AND DESIGN

Table 1.2.5 Variable Dimensions

Parking Garage: Fundamentals

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SOURCES

PLANNING AND DESIGN

types

fundamentals

INTROdUCTION

Table 1.2.6 Variable Dimensions

fundamentals types PLANNING AND DESIGN

1.2 Stall Layouts

INTROdUCTION

Parking Garage: Fundamentals

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

18’-0”

18’-0” 8’-0”

8’-0”

8’-0”

8’-0”

5’-0” 8’-0”

ing stalls are 8’-0” and 18’-0” respectively. An 8’-

stalls are 8’-0” wide and a depth of 18’-0”. A 5’-0”

disabled individuals must be taken into consider-

0” clear isle must be located directly adjacent to

clear isle must be located directly adjacent to the

ation when designing a parking garage. All public

the handicap accessible parking stall. Two van

handicap accessible parking stall. Two accessi-

parking garages must accommodate disabled

accessible parking stalls may share a single 8’-0”

ble parking stalls may share a single 5’-0” wide

individuals. The following section includes acces-

wide clear aisle way. Refer to Table 1.3.5 to deter-

clear aisle way. Refer to Table 1.3.5 to determine

sible parking stall quantity and sizes, height

mine the number of accessible parking stalls

the number of accessible parking stalls required

restrictions, and ramp slopes. Refer to Chapter 3

required, and refer to local zoning code for more

per number of parking stalls, and refer to local

Planning and Design for further information

information.

accessible

pedestrian

8’-0”

8’-0” 8’-0” zoning code 8’-0” for more information.

circulation

Figure 1.3.2 Height Clearance

Figure 1.3.4 On-Ramp Parking Slope

9’-0” 20

1

SLOPE: 5% MAX 8’-0”SLOPE) 8’-0” (2% CROSS Accessible minimum clear height of a parking

Accessible on-ramp parking slopes can be a

level from finish floor to finished ceiling shall be no

maximum of 1:20 (5%). The cross slope can be a

less than 8’-2”. Bottom of structure, finishes, and

’-6 13

the location of an accessible route.

”

”

6” infrastructure must not project below 8’-2” clear in 24’-0

more information as well as local zoning and

18’-0”

Refer to the section 1.1 Basic Dimensions for handicap codes.

18’-0”

8’-0”

18’-0”

for individuals with disabilities. Accessibility for

7’-0” 18’-0”

Minimum width and depth for accessible parking

8’-2”

types

Figure 1.3.3 Parking Stall Size

Minimum width and depth for accessible van park-

around core elements such as stairs and elevator.

PLANNING AND DESIGN

5’-0” 8’-0”

Accessible parking refers to the parking provided

regarding

SOURCES

8’-0”

Figure 1.3.1 Van Parking Stall Size

18’-0”

Accessible Parking

fundamentals

INTROdUCTION

1.3

maximum slope of 2%. (Note: On-Ramp parking

CLEAR for non-disabled individuals must meet the criteria described above.) 30’-0” MAX

INTROdUCTION fundamentals types

1.3 Accessible Parking

PLANNING AND DESIGN

Table 1.3.5 Accessible Parking Stalls

Parking Garage: Fundamentals

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

Level of Service

i vis

1.4

fundamentals

se ru to

familiar use

types

% FULL 100% 90% 80% 70%

PLANNING AND DESIGN

60% 50% 40% 30% 20%

AM/PM

PEAK HOUR PER USE

7:00

6:00

5:00

4:00

3:00

2:00

1:00

12:00

11:00

10:00

9:00

8:00

7:00

SOURCES

10%

IN OUT

high turnover low turnover

Level of Service highest level of service and representing a class

a lower level of parking can be used where as a

traffic engineers to assess the quality of streets

of user that is not familiar with the facility and LOS

patron of a retail facility may not be familiar with

and its users and was later adopted by parking

D the lowest level of service representing those

the facility and so a mid level of service might be

consultants for parking design to assign a cate-

highly familiar with the facility. LOS is also deter-

appropriate. In high turnover situations such as at

gory of quality and use to structures. Walker

mined by location. In a dense urban area affected

an airport, a high level of service will be most

Parking Consultants of Boston pioneered this

by scarcity of land, a lower level of service may

appropriate to facilitate unfamiliar users pressed

cross application of assigning levels of service to

naturally arise. LOS is virtually the first variable

for time to catch their flight. While there is no one

parking facility design. LOS varies according to

that should be considered when designing any

standard that is used for each facility, many facili-

different circumstances and is essentially a factor

kind of parking facility. Questions that will surface

ties are a hybrid of levels of service, this chapter

of use, familiarity and turnover. Figure 1.17 gives

initially such as who is the user and how long are

provides a brief snap shot of the general consider-

an overall snapshot of use and turnover. Particular

they generally expected to stay at their destina-

ations and requirements of levels of service for

usage is mapped below. Within parking applica-

tion will determine what level of service will be

the architect to make informed decisions during

tions there are four recognized levels of service

appropriate. For example, an employee is often

the schematic phase of design.

ranging from A through D with LOS A being the

very familiar with a parking garage and therefore

100%

100%

80%

80%

types

Level of Service (LOS) is a standard utilized by

fundamentals

1.4 Level of Service

INTROdUCTION

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

70%

Figure 1.18 Turnover during morning and afternoon/evening peak hour per use

6:00

7:00

4:00

PEAK HOUR

5:00

AM/PM

PERCENT FULL

3:00

2:00

12:00

11:00

9:00

10:00

7:00

6:00

7:00

4:00

PEAK HOUR

5:00

3:00

2:00

1:00

12:00

11:00

10%

9:00

20%

10%

10:00

30%

20%

8:00

30%

7:00

40%

AM/PM

VISITOR

50%

40%

PERCENT FULL

Hospital Visitor

60%

FAMILIAR

50%

1:00

Hospital Employer

8:00

60%

Figure 1.19

SOURCES

70%

PLANNING AND DESIGN

90%

90%

100%

80%

80%

70%

70%

60%

60%

90%

90%

50%

types

6:00

7:00

4:00

5:00

AM/PM

PERCENT FULL

3:00

12:00

11:00

10:00

9:00

8:00

PEAK HOUR PERCENT FULL

PEAK HOUR

Figure 1.20

Figure 1.21

100%

90%

90%

PEAK HOUR PERCENT FULL

Figure 1.22

6:00

7:00

5:00

4:00

AM/PM

PERCENT FULL

3:00

VISITOR

2:00

7:00

6:00

5:00

4:00

AM/PM

3:00

2:00

1:00

12:00

10%

11:00

20%

10%

10:00

20%

9:00

30%

8:00

30%

Convenience Rateial / Banking

1:00

FAMILIAR

40%

12:00

50%

11:00

Residential

40%

10:00

60%

50%

9:00

70%

60%

8:00

80%

70%

7:00

80%

7:00

PLANNING AND DESIGN

7:00

6:00

7:00

5:00

4:00

3:00

2:00

1:00

12:00

11:00

10%

10:00

10%

8:00

20%

7:00

20%

AM/PM

VISITOR

30%

100%

SOURCES

General Retail / Restaurant

40%

FAMILIAR

30%

2:00

Office

40%

1:00

50%

9:00

INTROdUCTION fundamentals

100%

PEAK HOUR

Figure 1.23

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

100%

80%

80%

70%

70%

60%

60%

50%

50%

90%

Medical Office

40%

Airport Mid-Term

6:00

PEAK HOUR

Figure 1.24

Figure 1.25

100%

100%

80%

80%

70%

70%

60%

60%

90%

7:00

5:00

4:00

AM/PM

PERCENT FULL

PEAK HOUR

3:00

1:00

12:00

11:00

10:00

8:00

Airport Long-Term

7:00

6:00

7:00

4:00

5:00

AM/PM

3:00

2:00

1:00

12:00

11:00

9:00

10:00

10%

8:00

10%

7:00

20%

PERCENT FULL

VISITOR

30%

20%

2:00

VISITOR

30%

9:00

40%

Airport Short-Term

fundamentals

90%

types

100%

INTROdUCTION

1.4 Level of Service

Figure 1.26

7:00

6:00

5:00

4:00

3:00

2:00

1:00

AM/PM

PERCENT FULL

SOURCES

PERCENT FULL

VISITOR

12:00

6:00

7:00

5:00

4:00

AM/PM

PEAK HOUR

3:00

2:00

1:00

12:00

11:00

10%

9:00

20%

10%

10:00

20%

8:00

30%

7:00

30%

Special Event

11:00

VISITOR

40%

10:00

50%

9:00

Hotel / Motel

8:00

40%

7:00

50%

PLANNING AND DESIGN

90%

PEAK HOUR

Figure 1.27

INTROdUCTION

Parking Structure Anatomy fundamentals

The components of the parking structure will vary depending on what level of service is chosen.

Parking structure components include structure as it relates to ceiling height, ramp slope, turning radii and turning bay dimensions, among many other components. Table 1.4 summerizes the major design parameters with regard to its specific level of service.

Figure 1.28 gives a snapshot map of the major types

design parameters to be considered that can be used as a quick tool during the earliest stages of preliminary planning. This section should be used in collaboration with the parking structure overall

SOURCES

PLANNING AND DESIGN

dimensions discussed later in this book.

Figure 1.28

1.4 Level of Service LOS A

LOS B

LOS C

LOS D

INTROdUCTION

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

300’-0” 9’-0” 9’-8” 5% 100’-0” 90%

600’-0” 8’-4” 9’-0” 5.50% 150’-0” 60%

900’-0” 7’-8” 8’-4” 6% 200’-0” 30%

1200’-0” 7’-0” 7’-8” 6.5% 250’-0” 0%

Nonpark Roadways

Lane Width Straight - One Lane Lane Width Straight - Multiple Lanes Lane Width Turning - One Lane Lane Width Turning - Each Additional Lane Turning Radius Circular Helix Outside Diameter - Single Threaded Circular Helix Outside Diameter - Double Threaded Clearance to Obstructions Express Ramp Slope Transition Length

11’-6” 10’-6” 13’-6” 12’-0” 42’-0” 102’-0” 125’-0” 2’-0” 8% 13’-0”

11’-0” 10’-0” 13’-6” 12’-0” 36’-0” 88’-0” 110’-0” 1’-6” 10.6% 12’-0”

10’-6” 9’-6” 13’-6” 12’-0” 30’-0” 74’-0” 95’-0” 1’-0” 13.3% 11’-0”

10’-0” 9’-0” 13’-6” 12’-0” 24’-0” 60’-0” 80’-0” 0’-6” 16% 10’-0”

Parking Areas

360 degree Turns to Top Turning Radius Short Circuit in Long Run Travel Distance to Crossover Spaces Searched / Passed - Angled Spaces Searched / Passed - Perpendicular Turning Bay - One Lane Turning Bay - Two Concentric Lanes

2.5 30’-0” 250’-0” 300’-0” 400 250 18’-3” 31’-0”

4 28’-0” 300’-0” 450’-0” 800 500 17’-0” 29’-9”

5.5 26’-0” 350’-0” 600’-0” 1200 750 15’-9” 28’-0”

7 24’-0” 400’-0” 750’-0” 1600 1000 14’-6” 26’-6”

Flow Capacity

Straight Lane Drive Ramp - One Way Straight Lane Drive Ramp - Two Way Circular Helix - Single Threaded Circular Helix - Double Threaded Turning Bays (no parking on end bay)

1858 1853 1715 1793 1345

1855 1850 1631 1761 1233

1853 1848 1473 1704 1097

1850 1845 1169 1589 936

Design Flow Capacity (Hourly Flow Rate v / Capacity C)

0.6

0.7

0.8

types

Maximum Walking Distance Clear Height - Slab Beam Clear Height - Other Construction Types Ramp Slope Maximum Distance to Open Side Percent Spaces on Flat Floor

PLANNING AND DESIGN

Wayfinding

fundamentals

DESIGN PARAMETERS

Table 1.4

SOURCES

NOT RECOMMENDED

INTROdUCTION fundamentals

Clear Height

LOS A

LOS B 8’-4”

Slab Beam 9’-0” Construction

Other Construction 9’-8” Types

types

9’-0”

LOS D

7’-8”

7’-0”

8’-4”

7’-8”

SOURCES

PLANNING AND DESIGN

LOS C

Figure 1.29

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

1.4 Level of Service

LOS A

5%

5.5%

types

LOS B

fundamentals

Ramp Slope

PLANNING AND DESIGN

LOS D

6%

6.5%

SOURCES

LOS C

Figure 1.30

INTROdUCTION

Parking Areas

fundamentals

LOS A

30’-0”

28’-0”

LOS D

LOS C

LOS B

26’-0”

24’-0”

SOURCES

PLANNING AND DESIGN

types

TURNING RADIUS

ONE LANE TWO CONCENTRIC LANES

18’-3”

31’-0”

17’-0”

29’-9”

15’-9”

28’-0”

14’-6”

26’-6” TURNING BAY

Parking Garage: Fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

1.4 Level of Service

Non-Park Roadways and Express Ramps

102’-0”

88’-0” 110’-0”

74’-0” 95’-0”

60’-0” 80’-0”

42’-0”

36’-0”

30’-0”

24’-0”

types

CIRCULAR HELIX

PLANNING AND DESIGN

TURNING RADIUS

13’-6”

13’-6”

13’-6”

13’-6” TURNING BAY

SOURCES

SINGLE

DOUBLE 125’-0”

LOS D

LOS C

LOS B

fundamentals

LOS A

INTROdUCTION

Parking Stall Geometrics fundamentals

Generally, LOS A is more generous in its distribu-

M

tion of space within a parking module. LOS B is

I

usually assigned to retail use and situations simi-

VP

VP

A

O

lar to LOS A with the main difference being the rate of turnover. LOS C is typically used for employee situations and LOS D will usually only be accepted in severe urban situations where

FACE OF CURB

space is limited.

SP

types

COLUMN ENCROACHMENT (2’ MAX)

WO SW WP

SO SL

SOURCES

PLANNING AND DESIGN

SP

SP

Figure 1.33

Parking Garage: Fundamentals

9’-0”

LOS B

8’-9”

LOS C

8’-6”

LOS D

8’-3”

LEGEND M A I O SP VP WP SW SL WO SO

Module Aisle Width Interlock Reduction Overhang Stripe Projection Vehicle Projection Width Projection Stall Width Stall Length Wall Offset Stripe Offset

(WO)

INTROdUCTION

(A)

(I)

(VP)

(O)

(SO)

49’-6” 54’-0” 57’-6” 61’-6”

14’-8” 16’-6” 19’-10” 26’-0”

3’-2” 2’-3” 1’-2” 0’-0”

17’-5” 18’-9” 18’-10” 17’-9”

10’-8” 7’-2” 3’-10” 1’-0”

1’-9” 2’-2” 2’-5” 2’-6”

16’-6” 9’-6” 4’-5” 0’-0”

45 60 75 90

12’-4” 10’-1” 9’-1” 8’-9”

48’-6” 53’-0” 56’-6” 60’-6”

13’-8” 15’-6” 18’-10” 25’-0”

3’-1” 2’-2” 1’-1” 0’-0”

17’-5” 18’-9” 18’-10” 17’-9”

10’-8” 7’-2” 3’-10” 1’-0”

1’-9” 2’-2” 2’-5” 2’-6”

16’-6” 9’-6” 4’-5” 0’-0”

45 60 75 90

12’-0” 9’-10” 8’-10” 8’-6”

47’-6” 52’-0” 55’-6” 69’-6”

12’-8” 14’-6” 17’-10” 24’-0”

3’-0” 2’-2” 1’-1” 0’-0”

17’-5” 18’-9” 18’-10” 17’-9”

10’-8” 7’-2” 3’-10” 1’-0”

1’-9” 2’-2” 2’-5” 2’-6”

16’-6” 9’-6” 4’-5” 0’-0”

45 60 75 90

11’-8” 9’-6” 8’-6” 8’-3”

46’-6” 51’-0” 54’-6” 68’-6”

11’-8” 13’-6” 16’-10” 23’-0”

2’-11” 2’-1” 1’-1” 0’-0”

17’-5” 18’-9” 18’-10” 17’-9”

10’-8” 7’-2” 3’-10” 1’-0”

16’-6” 1’-9” 9’-6” 2’-2” Table 1.5 4’-5” 2’-5” 0’-0” 2’-6”

fundamentals

(M)

12’-9” 10’-5” 9’-4” 9’-0”

types

LOS A

(WP)

45 60 75 90

ANGLE

PLANNING AND DESIGN

STALL WIDTH DIMENSIONS

1.4 Level of Service

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Types

Type A

Type B

One of the most unique architectural element

through architectural means, it does not fit into the

This chapter will focus its analysis on five different

associated with the typology of the parking

category of ramp, structured parking garages.

ramping configurations, or types. Starting from

structure is the ramp. Its use can be both functional

Therefore, it will not be addressed in this book.

the simplest in form, the two-way single helix is a

The ramp was first introduced in 1914, with a split

maximizes space by using the sloped surface

structure or facade. Perhaps no other building

level garage, where the length of the ramp is

both for driving and parking. Type B, the one-way

typology can make claim to such a unique,

shortened by half stepping the floors. (This ramp

double helix, takes a similar approach to type A,

identifying element.

type is shown below.) Parking garage ramps

while using two interconnected ramps to allow

finally gained full acceptance in 1922, and the

dedicated drive aisles for cars moving in different

As it has developed over the past several decades,

elevator was phased out of use, when Albert Kahn

directions. The split level ramp, type C, uses flat

the

various

created the continuous ramp for driving and

floor plates for parking and small ramps to connect

configurations, each searching for a different way

parking for the Fort Shelby Garage in Detroit. This

the different levels. Type D, the two-way center

to solve the same problem: moving cars. The

ramp type maximized the number of parking

ramp, also uses flat plates for parking with a

earliest ramps utilzed freight elevators, which

spaces,

and

central ramp connecting each level. Perhaps the

originated in warehouses, to transport cars

created a constant flow of traffic through the

most unqiue coniguration, the speedway ramp,

vertically,

because

garage. In 1935, the open-deck garage was

type E, uses spiral ramps attached to a flat plate

mechanized parking is now on the forefront of

invented and was widely accepted as the norm

system, to minimize the footprint needed for the

structured

once gasoline and engines were made to

ramping system.

parking

ramp

which parking.

has

is

taken

on

interesting

Mechanized

parking

is

extremely efficient spatially, but because it moves

eliminated

parking

attendents,

fundamentals

well developed, widely used system which

movement of vehicles as well as define a building’s

types

and aesthetic, acting to facilitate the vertical

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

withstand extreme drops in temperature.

SOURCES

PLANNING AND DESIGN

cars through mechanical intervention, rather than

Type C

Type D

Type E

INTROdUCTION fundamentals types PLANNING AND DESIGN SOURCES

A

Two Way Single Helix

Type A, or the Two Way Single Helix ramp garage,

vehicular conflicts and it needs wider parking

is a continuous ramp that rises one tier every 360

modules. Wider parking modules are necessary

degrees. The main benefit of the Two Way Single

because of the two lanes needed for traffic and

Helix ramp is that the single continuous ramp is

because 90 degree stalls are best suited to avoid

easy to navigate for unfamiliar visitors. Type A

difficult parking maneuvers. Vertical pedestrian

garages should not be designed for high peak vol-

circulation is most often placed in the corners of

ume use or large capacity parking. The problem

the flat areas, in the space unusable for parking.

with the single ramp is that it forces Type A to

This allows for all accessible parking to be located

have two way traffic. Two way traffic can be neg-

on the flat areas, and eliminates the need for more

ative because it creates more opportunities for

gradually sloped ramps and a large floor plate.

A Two Way Single Helix

INTROdUCTION

Parking Garage: Types

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SOURCES

PLANNING AND DESIGN

types

90 degree stalls are best suited for two way traffic to avoid difficult parking maneuvers.

Typical Vertical Pedestrian Circulation

INTROdUCTION

Type A Planning Formula

fundamentals

2 [18cosine(SA) + 8.75tangent(SA)] + (2)AW + [100(HH + SD)]/RS = L The formula above determines the overall length of a Type A, Two-Way Single Helix parking garage ramp. All lengths are in feet and all abbreviations are represented in the top row of the matrix to the right.

This

matrix

calculates

three

garage

configurations, taking into account the variables in the equation above in order to convey small,

types

typical, and large parking garages.

SOURCES

vpW

AW

RL

SD

L

HH

PLANNING AND DESIGN

This turning radius verifies the minimum aisle width first listed in the Fundamentals section 1.x.

RS

Parking Garage: Types

STALL DEPTH

AISLE WIDTH

VPw

AW

STRUCTURAL DEPTH

HEAD HEIGHT

RAMP SLOPE

LENGTH

SA HH

RS%

SD

(PLAN SIZE)

(SA) (DEGREE)

(VP w) (FT)

MINIMUM (AW) (FT)

(SD) (FT)

(HH) (FT)

(RS) (%)

(L) (FT)

MINIMUM

90

18.0

24.0

2.0

7.0

6.5

152.6

TYPICAL

90

18.0

24.0

2.0

8.5

6.0

166.2

LARGE

90

18.0

24.0

2.0

10.0

5.0

204.0

The matrix calculates three different overall

-place concrete structure. See the structure

the minimum and maximum heights. The ramp

lengths based upon changing variables processed

section in Part 4 for design considerations. The

slopes range from 5% to 6%, which are all allowed

through the given equation. Since Type A is a

head height ranges from a minimum of 7’-0”

for ramps in which cars drive and park, which is

two-way traffic ramp, stall configurations must be

required by in the International Building Code

the case for Type A. Each of these configurations

at 90 degrees. Vehicular projection is based upon

(IBC) to a maximum of 10’-0” to prevent oversized

are diagrammed in the following pages. In

the equation stated before. The aisle width for

vehicles from entering the garage. A head height

addition, the efficiency of each option is described

ramp Type A is always 24’-0” because the traffic

of 8’-2” is required to accomodate accessible

by the number of square feet per stall. This

is two-directional. The structural depth of 2’-0” is

vehicles, but 8’-6” has been used here as a typical

number is determined by dividing the total square

based upon a typical beam and slab, poured-in

head height because it falls precisely between

footage by the number of parking stalls.

types

STALL ANGLE

PLANNING AND DESIGN

Type A Matrix

fundamentals

INTROdUCTION

A Two Way Single Helix

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals

Type A Plans and Sections

Typical Plan_90°

62 Stalls 122’-0”

Per level of parking

20,271 GSF

types

Per level of parking 90°

326.92 SF

PLANNING AND DESIGN

Per parking stall

18’-0”

This number defines the efficiency of the plan, given the parking stall configuration, ramp slope, and floor to ceiling height.

Compare this number to those of other configurations within a ramp type to determine the most efficient parking and dimensional configuration given the ramp type.

22’-0”

8’-6”

SOURCES

2’-0”

166’-2”

6%

A Two Way Single Helix

fundamentals

When designing a two-way, 90 degree parking ramp, the longer the ramp, the more efficient the ramp because the ratio between wasted corner space and usable parking space is reduced.

Large Plan_90°

Minimum Plan_90°

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

types

122’-0”

122’-0”

90°

PLANNING AND DESIGN

90°

204’-0”

54 Stalls

18,629 GSF

344.98 SFper stall

5%

78 Stalls

24,888 GSF

319.08 SFper stall

SOURCES

7’-0”

6.5%

10’-0”

2’-0”

2’-0”

152’-7 1/2”

INTROdUCTION SOURCES

PLANNING AND DESIGN

types

fundamentals

Type A Valet Parking

The previous three plans convey the efficiency of

It should be noted that valet parking is not typically

different floor plates in respect to the allotted

used for new structures. Retro-fitted garages

parking stalls. Every parking structure, however,

often take advantage of valet parking because of

can utlize valet parking in order to maximize the

odd configurations and an inefficient floor layout.

number of cars in a given space. The plan on the

However, the number of employees necessary to

following page diagrams where extra cars could

valet park an entire garage is most often not as

be located if parking attendants parked and

cost-effective as choosing the correct ramp type

controlled all vehicles.

and designing the garage to maximize the number of

stalls.

Nevertheless,

valet

parking

is

diagrammed for each ramp type to demonstrate how efficiency of floor space is increased, without regards to any other factors.

A Two Way Single Helix

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Valet Plan_90° fundamentals

78 Stalls Per level of parking

26 Extra Cars

Per level of parking

types

24,888 GSF

122’-0”

Per level of parking

239.31 SF Per parking stall

5%

SOURCES

2’-0”

204’-0”

10’-0”

By adding a level of valet parking, the efficiency increases by 25% for 90 degree parking stall configurations.

PLANNING AND DESIGN

(with added valet)

INTROdUCTION fundamentals

B

Central Two Way Ramp

Type B, or the Central Two Way Ramp garage, is

bays, which create a wide parking module, and

usually configured 3 bays wide, with the central

they are not great for high peak volume use.

bay being the ramp between tiers. The main ben-

Parking can be on the central two way ramp if the

efits of Type B garages are that they can be made

slope and width of the garage allows it. This cre-

to very large sizes while still being fairly intuitive

ates a much higher efficiency. Vertical pedestrian

for infrequent visitors, and the flat floor plate

circulation is most often placed in the unusable

allows for some flexibility in vertical pedestrian

parking areas in the corners, but there is flexibility

circulation and accessible parking. The negatives

because of the flat floor plate.

SOURCES

PLANNING AND DESIGN

types

of Type B garages are that they need at least 3

B Central Two Way Ramp

INTROdUCTION

Parking Garage: Types

SOURCES

Many Type B garages do not have parking on the central ramp because of the steep slope that is necessary to span the distance between floors.

PLANNING AND DESIGN

types

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Typical Vertical Pedestrian Circulation

INTROdUCTION

Type B Planning Formula

fundamentals

2 [18cosine(SA) + 8.75tangent(SA)] + (2)AW + [100(HH + SD)]/RS = L

The formula above determines the overall length types

of a Type A, Two-Way Single Helix parking garage ramp. All lengths are in feet and all abbreviations are represented in the top row of the matrix to the right.

This

matrix

calculates

three

garage

configurations, taking into account the variables in the equation above in order to convey small,

SOURCES

vpW

AW

RL

SD

L

HH

PLANNING AND DESIGN

typical, and large parking garages.

RS

Parking Garage: Types

STALL DEPTH

AISLE WIDTH

VPw

AW

STRUCTURAL DEPTH

HEAD HEIGHT

RAMP SLOPE

LENGTH

SA HH

RS%

SD

(PLAN SIZE)

(SA) (DEGREE)

(VP w) (FT)

MINIMUM (AW) (FT)

(SD) (FT)

(HH) (FT)

(RS) (%)

(L) (FT)

MINIMUM

45

19.1

11.0

2.0

7.0

15

119.75

TYPICAL

60

20.0

17.0

2.0

8.0

14

145.0

TYPICAL

75

19.4

21.0

2.0

9.0

13

165.3

LARGE

90

18.0

24.0

2.0

10.0

12

172.75

types

STALL ANGLE

PLANNING AND DESIGN

Type B Planning Matrix

fundamentals

INTROdUCTION

B Central Two Way Ramp

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

Type B Plans and Sections

fundamentals

Minimum Plan_45° 45°

28 Stalls Per level of parking

18,629 GSF 122’-4”

Per level of parking

types

344.98 SF Per parking stall

19’-1”

11’-0”

59’-10”

2’-0”

119’-9”

7’-0”

SOURCES

PLANNING AND DESIGN

Notice the efficiency for 45 degree parking is extremely low.

Therefore it is not recommended for parking structures.

Subsequently, it will not be shown for subsequent ramp types.

15%

B Central Two Way Ramp

Typical Plan_60 °

fundamentals

Typical Plan_75°

60°

71’-0”

19’-4”

21’-0”

145’-0”

84’-8”

9’-0”

2’-0”

2’-0”

165’-4”

14%

54 Stalls

18,629 GSF

344.98 SFper stall

13%

54 Stalls

18,629 GSF

344.98 SFper stall

SOURCES

17’-0”

PLANNING AND DESIGN

types

138’-0”

138’-0”

75°

20’-0”

8’-0”

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals

Large Plan_90°

90°

54 Stalls

142’-0”

types

18,629 GSF

344.98 SF

18’-0”

23’-0”

90’-9”

2’-0”

172’-9”

10’-0”

SOURCES

PLANNING AND DESIGN

per stall

12%

B Central Two Way Ramp

fundamentals

Type B Valet Parking

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Valet Plan_90°

54 Stalls

types

18,629 GSF

142’-0”

24 Extra Cars

238.83 SF Per parking stall

18’-0”

23’-0”

90’-9”

10’-0”

2’-0”

172’-9”

12%

SOURCES

By adding a level of valet parking, the efficiency increases by 31% for 90 degree parking stall configurations.

PLANNING AND DESIGN

(with added valet)

INTROdUCTION fundamentals

C

One Way Double Helix

Type C, or the One Way Double Helix garage, is

garage only once, with no retracing of their paths.

composed of two interlocked ramps that create a

The main negative of One Way Double Helix

continuous loop. The main benefits of the One

garages is that they are not very intuitive for infre-

Way Double Helix is that users can enter and exit

quent visitors, and should be planned for facilities

without ever retracing their path and the configu-

with regular users.

ration minimizes congestion and conflicts between

pedestrian circulation and accessible parking is

vehicles. A driver in a Type C garage will have

most often limited to the unusable space for park-

roughly have half the turns and circulation dis-

ing in the corners on the flat areas.

tance of a driver in a Type A garage with the same

pedestrian circulation can be placed in other

floor plate. This makes the One Way Double Helix

areas if the slope of the garage is gradual enough

very efficient in facilities with high peak volumes.

to allow for accessible movement.

SOURCES

PLANNING AND DESIGN

types

It also allows users to pass every space in the

Similar to Type A, vertical

Vertical

C One Way Double Helix

INTROdUCTION

Parking Garage: Types

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SOURCES

PLANNING AND DESIGN

types

Crossover aisles between adjacent ramps provide shortcuts for exiting.

Typical Vertical Pedestrian Circulation

INTROdUCTION

Type C Planning Formula

fundamentals

2 [18cosine(SA) + 8.75tangent(SA)] + 2(AW) + DA + 2[(100(HH + SD)] / 2(RS) = L

The formula to determine the overall length of a Type C, double helix parking ramp is slightly different than the previous two. The drive aisle (DA) is introduced as the flat surface at least 24’0� to provide a cross-over point for vehicles on the one-way ramp to switch direction. Also, the ramp must be calculated in two parts, since the drive of the formula takes this into consideration.

vpW

SOURCES

AW

da RL

SD

L

RS HH

PLANNING AND DESIGN

types

aisle breaks the ramp in the middle. The last part

Parking Garage: Types

Type C Planning Matrix

AISLE WIDTH

VPw

AW

DRIVE AISLE STRUCTURAL DEPTH HEAD HEIGHT RAMP SLOPE

LENGTH

SA

(PLAN SIZE)

(SA) (DEGREE)

DA

(VP w) (FT)

MINIMUM (AW) (FT)

(DA) (FT)

HH

RS%

SD

(SD) (FT)

(HH) (FT)

(RS) (%)

(L) (FT)

MINIMUM

45

19.1

11.0

24.0

2.0

7.0

6.5

221.25

TYPICAL

60

20.0

17.0

24.0

2.0

8.0

6.0

254.5

TYPICAL

75

19.4

21.0

24.0

2.0

9.0

5.5

321.8

LARGE

90

18.0

24.0

24.0

2.0

10.0

5.0

346.0

types

STALL DEPTH

PLANNING AND DESIGN

STALL ANGLE

fundamentals

INTROdUCTION

C One Way Double Helix

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Typical Plan_75°

fundamentals

INTROdUCTION

Type C Plans and Sections

114 Stalls 75°

types

122’-7”

39,517 GSF

346.64 SF per stall

19’-4” 21’-0”

241’-3”

2’-0”

5.5%

SOURCES

9’-0”

PLANNING AND DESIGN

321’-10”

Typical Plan_60°

45°

60°

11’-0”

types

19’-1”

117’-4”

101’-4”

Minimum Plan_45°

fundamentals

C One Way Double Helix

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

161’-3” 221’-3”

19’-1”

11’-0”

180’-6”

46 Stalls

22,419 GSF

487.38 SFper stall

PLANNING AND DESIGN

6%

8’-0”

7’-0”

6.5%

76 Stalls

28,797 GSF

378.91 SFper stall SOURCES

2’-0”

2’-0”

245’-6”

INTROdUCTION fundamentals

Large Plan_90°

types

121’-0”

90°

264’-0”

23’-0”

SOURCES

PLANNING AND DESIGN

18’-0”

346’-0”

5%

136 Stalls

41,866 GSF

307.83 SFper stall

C One Way Double Helix

Type C Valet Parking

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

types

121’-0”

fundamentals

Valet Plan_90°

346’-0”

By adding a level of valet parking, the efficiency increases by 23% for 90 degree parking stall configurations.

136 Stalls

39 Extra Cars

41,866 GSF

239.23 SFper stall (wtih added valet)

PLANNING AND DESIGN

264’-0”

23’-0”

SOURCES

18’-0”

INTROdUCTION fundamentals types PLANNING AND DESIGN SOURCES

D

Split Level

Type D, or the Split Level garage, is formed by

lation of a Type D garage is very similar to that of

staggered, level tiers that are connected by speed

a Type A garage in which users must retrace their

ramps at the ends. The main benefits of a Split

path to exit the garage, and two way traffic flow is

Level garage are that all parking is located on a

necessary. Vertical pedestrian circulation is most

flat floor plate, it can be constructed on a highly

often placed in the center between the ramps. It

constrained site, and like Type A it is easy to navi-

can be placed at the corners but this would require

gate by visitors unfamiliar with the facility. The

much more vertical circulation then is needed.

main negative aspects are that it does not do well

Vertical pedestrian circulation is awkward in Split

with high peak volume, pedestrian circulation is

Level garages because elevators must stop at

difficult, and two way traffic creates more driver

every staggered tier. However, because no park-

conflicts and limits the designer to either 90

ing occurs on ramps, horizontal pedestrian circu-

degree stalls or more difficult parking. The circu-

lation is very comfortable.

SOURCES

Type C garages are the only types of garages where vertical pedestrian circulation is often located in the center of the garage.

PLANNING AND DESIGN

types

fundamentals

D Split Level

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Typical Vertical Pedestrian Circulation

INTROdUCTION

Type D Planning Formula

fundamentals

2 [18cosine(SA) + 8.75tangent(SA)] + 2(AW) + SW + 100(HH + SD) / RS = W

The ramps in Type D are oriented perpendicular to those of the previous three ramp types. Given the nature of the garage, in that the floor plate is sliced and staggered longitudinally, the ramps are types

place at the shorter ends in order to move drivers from one side of the floor plate up to the other.

Therefore, the formula above calculates the width, instead of the length, because the changing ramp length, given the varying head height and ramp angles, effects the overall width of the structure.

All of the plans are rotated 90 degrees in this

vpW

RL W

for proportional consistency to other ramp types

sd

In the minimum plan, the length is set at 125’-0” and increased by 25’-0” for each consecutive plan. The length is increased because the width changes only martinally and therefore does not clearly express a difference in efficiency. As with Type A, the drive aisles are two-way so only 90

SOURCES

sw

AW

Also, there is no minimal dimension for the length.

degree parking stall configurations have been shown. Also, the larger the plan, the more efficient a garage, as will be shown in the following pages.

hh

PLANNING AND DESIGN

section to show the relationship to the section.

rs

Parking Garage: Types

Type D Planning Matrix

STALL DEPTH AISLE WIDTH STRUCTURAL WIDTH STRUCTURAL DEPTH HEAD HEIGHT RAMP SLOPE WIDTH

AW

VPw

SW

HH

RS%

SD

(PLAN SIZE)

(SA) (DEGREE)

(VP w) (FT)

MINIMUM (AW) (FT)

(Sw) (FT)

(SD) (FT)

(HH) (FT)

(RS) (%)

(W) (FT)

MINIMUM

90

18.0

24.0

2.0

2.0

7.0

15.0

122.0

TYPICAL

90

18.0

24.0

2.0

2.0

8.5

13.5

122.8

LARGE

90

18.0

24.0

2.0

2.0

10.0

12.0

130.2

The width in Type D does not increase as

previous page only applies to floor plans where the

drastically as the variables differ because the

ramp length is greater than 36’-0”. Both the right

middle bay for parking is sometimes longer than

and left side levels share a common structural

the length of the ramp. This is the case for the

wall or location for columns. If the floor-to-ceiling

minimum plan. The length of the ramp in the

height is great enough to overlap levels and fit cars

typical plan is slightly longer than the width of the

underneath, this decreases the projection of the

central bay. Therefore, the difference between

central bay of parked cars into the drive aisle of each

the overall width for the minimum and typical

level. However, the floor plate does not decrease

plans is not simply the difference between the

because the drive aisle still needs to fit

two ramp lengths, as is the case for other ramp

between the ramp and outside parking lane.

types. Consequently, the formula listed on

types

SA

PLANNING AND DESIGN

STALL ANGLE

fundamentals

INTROdUCTION

D Split Level

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

Type D Plans and Sections

fundamentals

Minimum Plan_90°

36 Stalls

15,250 GSF requires a different equation to determine the

125’-0”

types

As previously described, the minimum floor plan

423.61 SF per stall

overall width. The central parking bay expands past the ramps. Therefore, the drive aisle of 24’-0” occurs between the end and central parking stalls for each level, instead of between the end parking lane and the end of the ramp. The formula to use for this plan and similar situations is described below.

SOURCES

“Type D Planning Formula” previously given.

90° 18’-0”

24’-0”

2’-0” 30’-0”

2’-0”

122’-0”

7’-0”

PLANNING AND DESIGN

The plans on the following page utlize the typical

4 [18cosine(SA) + 8.75tangent(SA)] + 2(AW) + SW = W 15%

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Large Plan_90°

INTROdUCTION

Valet Plan_90°

18’-0” 24’-0”

18’-0” 24’-0”

46’-2” 2’-0”

2’-0”

48 Stalls

10’-0”

2’-0” 8’-6”

13.5%

46’-2” 130’-2”

130’-2”

12%

60 Stalls

12%

60 Stalls / 16 Extra Cars

18,435 GSF

22,785 GSF

22,785 GSF

384.07 SFper stall

379.75 SFper stall

299.8 SFper stall

SOURCES

38’-10” 122’-10”

10’-0”

24’-0”

PLANNING AND DESIGN

types

150’-0”

175’-0”

175’-0”

fundamentals

Typical Plan_90°

D Split Level

INTROdUCTION fundamentals types PLANNING AND DESIGN SOURCES

E

Express Ramp

Type E, or theExpress Ramp garage, consists of

layout. The main negative of the Type garage is

a large parking tier with either an internal or exter-

that the ramps devoted to only circulation create

nal express ramp devoted to purely traffic flow.

inefficiency in the garage, especially if it is of a

This express ramp can be a straight ramp or a spi-

small scale. Vertical pedestrian circulation can be

ral ramp. The main benefits of the Express Ramp

located essentially anywhere that is most conve-

garage are that ability to offer high capacities,

nient because of the open, flat floor plate. As in

high user comfort, and to manage high peak

every garage, the most efficient use of vertical

flows. It also can be used for infrequent visitors

pedestrian circulation is in the corners where the

as well as regular visitors because of its simple

space is unusable to parking.

Type E garages include many different alternative ramping configurations, such as helical ramps.

Express ramps can be either internal or external.

Typical Vertical Pedestrian Circulation

SOURCES

PLANNING AND DESIGN

types

fundamentals

E Express Ramp

INTROdUCTION

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

Type E Planning Formula

W vpW

AW

fundamentals

4 [18cosine(SA) + 8.75tangent(SA)] + 2(AW) = W 2(AW) + (100(HH + SD) / RS = RL

Given that the speed ramp in Type E is not actually integrated with the floor plate, there is no formula to determine the overall dimensions given variables such as the head height, structural types

depth, and ramp slope. Instead, this ramp type has been diagrammed with a typical 30’ x 30’ poured-in-place concrete structural grid. The four stall configurations have been placed within this grid to show the efficiency of 90 degree parking stalls and the inefficiency of any smaller angle.

The dimensions of the floor plate, discluding the above. This formula calculates the width, given a 4-bay structural grid with consideration for the parking stall configuration. The length for each of a 5-bay structural grid. The length of the ramp

traffic. The following matrix and plans demonstrate how the sharper the angle, the smaller the floor plate, as was the case for previous ramp types.

RL rs

(RL) is determined by the second formula and the width is consistently 48’ to accomodate 2-way

SOURCES

sd

the following plans is set at 153’-0” to accomodate

hh

PLANNING AND DESIGN

ramp on the end can be calculated by the formula

Parking Garage: Types INTROdUCTION

E Express Ramp

Type E Matrix

STALL ANGLE

STALL DEPTH

AISLE WIDTH STRUCTURAL DEPTH HEAD HEIGHT RAMP SLOPE

VPw

AW

RAMP LENGTH

WIDTH

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SA HH

(VP w) (FT)

MINIMUM (AW) (FT)

(SD) (FT)

(HH) (FT)

(RS) (%)

(L) (FT)

(L) (FT)

MINIMUM

45

19.1

11.0

2.0

7.0

15

78.0

107.5

TYPICAL

60

20.0

17.0

2.0

8.0

14

84.0

113.6

TYPICAL

75

19.4

21.0

2.0

9.0

13

90.3

118.3

LARGE

90

18.0

24.0

2.0

10.0

12

97.0

120.0

PLANNING AND DESIGN

(SA) (DEGREE)

SOURCES

(PLAN SIZE)

types

RS%

SD

INTROdUCTION

Type E Plans and Sections 113’-8” 20’-0” 17’-0”

fundamentals

Typical Plan_60°

28 Stalls

types

153’-0”

21,422 GSF

765.07 SF

48’-0”

PLANNING AND DESIGN

per stall

2’-0” 8’-0”

SOURCES

84’-0”

14%

Notice the efficiency for 60 degree parking is the lowest of any parking ramp type. The 45 degree stall configurations is mor efficient because it holds only one less stall and has a much smaller floor plate.

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

107’-6”

INTROdUCTION

E Express Ramp

118’-4”

19’-1” 11’-0”

19’-4”

27 Stalls

30 Stalls

20,206 GSF

22,424 GSF

per stall

per stall

48’-0”

PLANNING AND DESIGN

747.47 SF

48’-0”

748.37 SF

types

153’-0”

fundamentals

Typical Plan_75°

153’-0”

Minimum Plan_45°

21’-0”

78’-0”

SOURCES

2’-0” 15%

9’-0”

7’-0”

2’-0”

90’-4”

13%

INTROdUCTION

120’-0” 18’-0”

24’-0”

46 Stalls

23,016 GSF

153’-0”

types

fundamentals

Large Plan_90°

500.35 SF

The 90 degree stall configuration is far more efficient for this ramp type than any of the

48’-0”

PLANNING AND DESIGN

per stall

other configurations because three stalls fit between the columns space 30’ apart, while only 2 stalls fit inbetween the columns for each of the other configurations. In addition, the

97’-0”

is 23’-0”, which is 1’-0” short of a 2-way drive aisle. Therefore, this configuration can become

10’-0”

SOURCES

2’-0”

back-up space required for 90 degree stalls

2-way with only a few additional feet added to the width, while the other configurations must 12%

be 1-way because of the angles of the stalls.

Parking Garage: Types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

E Express Ramp

Type E Valet Parking 120’-0” 18’-0”

24’-0”

fundamentals

Valet Plan_90°

46 Stalls

types

23,016 GSF

153’-0”

26 Extra Cars

319.66 SF

PLANNING AND DESIGN

per stall

ramp type of the five. Since the ramp is not incorporated with the floor plate, the additional square footage necessary to move cars from one

48’-0”

Even with valet parking, this is the least efficient

floor to the next severly hinders the efficiency of parking in terms of square foot required

97’-0”

per stall. This ramp type is useful for cars to

10’-0”

traffic conditions with a high rate of turnover.

SOURCES

exit quickly and is therefore helpful in high

12%

Planning and Design

Once an appropriate ramp type is selected and design fundamentals are fully understood, an architect will begin to face more specific issues of planning and design. This chapter will explore these issues, focusing on the following topics: structural systems, enclosure strategies, regional

PLANNING AND DESIGN

types

fundamentals

INTROdUCTION

Parking Garage: Planning and Design

economics, groundfloor planning, pedestrian access, and user behavior.

Each section will

examine the decision making process facing the designer in regard to that particular issue, and how it may affect the overall success of a parking structure.

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

3.1 Structural

Systems

Typical Structure Bays Column layout is the most important structure A

proper column arrangement is neccessary in order to utilize every square foot of a parking garage.

Different structure systems allow for

different column layouts. Sitcast structures tend

15’-0”

fundamentals

consideration concerning parking garages.

to use more columns due to a shallow concrete slab. Precast elements can be post-tensioned,

30’-0”

allowing for spans reaching up to 60 feet. This allows for less columns, however the columns structures are the most ideal for column layouts, for the reason that they can be moved to the exterior.

However they must be fireproofed,

which brings up cost and affects apperience.

The following 5 plans are typical column layouts for parking garages utilizing sitecast, precast or steel structures.

PLANNING AND DESIGN

15’-0”

types

used are bulky and can hinder striping. Steel

A two way sitecast slab system yeilds the least efficient column layout. Columns are located within the parking deck, making it difficult for re-striping. Avoid using this layout only if neccessary or specified by the client.

30’-0”

1.

This type of structure layout is used for pouredin place construction. Sitcast concrete systems can not span as long as precast or steel, therefore more columns must be used, limiting the total number of spots per floor. Column configu-

SOURCES

ration also limits striping possibilities.

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

types

40’-0”

60’-0”

fundamentals

INTROdUCTION

3.1Structural Systems

3.

4.

This structure layout can be used for poured-in-

This type of column layout can be used for either

A steel column layout allows for maximum

place two-way systems such as Pan-Joist or

precast or steel structure parking garages. This

spaces without any obstruction. Columns are

Waffle Slab. Columns are larger than that of

example uses a precast double tee system.

pushed to the exterior and interior columns are

structure bay # 1, allowing for longer spans.

Columns are consumed within the spaces, alow-

located in-between slabs.

However the column placement will still interupt

ing for a maximum parking configuration. These

space striping.

spaces are therefore designated for smaller vehicles.

SOURCES

25’-0”

2.

PLANNING AND DESIGN

45’-0”

30’-0”

40’-0”

INTROdUCTION

Sitecast Structure Bay Cast-in-place concrete systems were developed before pre-cast concrete and steel systems became a viable option. Many new technolozation

of

finishing,

have

kept

30’-0”

fundamentals

gies, such as re-usable formwork and mechanisitecast

construction a favorable option.

Construction time is much longer due to the assembly of formwork and reinforcing bars. This type

of

system

must

be

constructed

floor-by-floor.

Two sitecast systems commonly used for parking garages are a Two-Way Flat Slab with Drop

types

Panels and a One-Way Joist Slab.

Two Way Slab with Drop Panels

15’-0”

Requires no beams and is heavily reinforced.

The typical slab depth is between 5 to 12 inches which minimizes floor-to-floor height. Drop panels are used to thicken the concrete in order to spans.

However this system requires a large

amount of columns.

1.1

1.2

8’-0” 18”

SOURCES

PLANNING AND DESIGN

resist high shear forces which allows for longer

30’-0”

15’-0”

6”

3.1Structural Systems

24”

8” 10” 6”

fundamentals

3’-6”

1.1

Parking Garage: Planning and Design INTROdUCTION

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

PLANNING AND DESIGN

types

1.2

SOURCES

The minimun size for drop panels is a width of one-third the span of the slab and a total depth of one and one-fourth times the depth of the slab. Panels may increase in size depending on heavier loads. Depth should be equal to a standard lumber dimension.

8’-0”

3’-0”

INTROdUCTION

Sitecast Structure Bay One-Way Joist Slab

A one-way joist slab utilizes plastic pan formwork to construct a slab.

If pan depths are

20’-0”

A slab is cast on top of the pans, which varies from 2 to 5 inches deep. Pan depth ranges from 20 to 30 inches depending on load.

60’-0”

1.1 8’-0”

SOURCES

24”

PLANNING AND DESIGN

types

fundamentals

increased, joists can span up to 60 feet or more.

1.2

6”

18”

6”

fundamentals

3’-6”

1.1

3.1Structural Systems

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SOURCES

A 3 inch thickness gives a 1 hour fire-rating. A 4 inch thickness gives a 1 1/2 hour fire rating. And a 5 inch thickness gives a 2 hour fire rating

18” (1) Joist Pan

8’-0”

16”

PLANNING AND DESIGN

types

1.2

INTROdUCTION

Precast Structure Bay Precast technology developed after sitecast construction and has become an economically The production of precast ele30’-0”

viable option. fundamentals

ments is more controlled and allows for advantages over sitecast construction. pouring

operaions

are

highly

Mixing and mechanized.

There is a control of quality and workers that is not seen on the job site.

Precast elements are bulky and are difficult to transport from factory to job site. Precast elements can only be as wide as the maximum legal vehicle width of 12 to 14 feet.

types

Double Tee System Depth of tees is varied upon span, member,

60’-0”

width and load. Standard length of double tees

1.1

8’-0”

SOURCES

34”

PLANNING AND DESIGN

is 60 feet.

1.2

8” 18”

28”

4” 2”

fundamentals

3’-6”

10’-0” (1) Double Tee Unit

A lite-wall is used to support the double tee system. Lite-walls are precast elements that extend from ground to top of garage. Openings are formed into the walls for security reasons within the garage.

8’-0”

12” 12”

PLANNING AND DESIGN

types

1.2

SOURCES

1.1

3.1Structural Systems

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

Steel Structure Bay New Technology has allowed for longer spans, with less the weight and floor-to-floor height. A steel structure layout allows for an open plan Steel is very expensive in todays market and you are not saving much when deciding to use this type of structure. It is costly to fireproof a steel 25’-0”

fundamentals

with very few columns which is ideal for parking.

structure where it is not needed for concrete structures. Maintenence must be upheld due to rust and corrosion build-up.

Elements A sitecast or precast concrete slab is used for types

the deck of the structure.

A slab depth can

range from 4 to 8 inches.

Steel beams can span long distances, up to 60 feet, with a depth of 30 inches. A W30 beam is

45’-0”

typical for parking structures.

A W12 beam is the most common column used

1.2

30”

1.1

SOURCES

8’-0”

PLANNING AND DESIGN

in parking garage construction.

45’-0”

45’-0”

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION

3.1Structural Systems

12” 6”

28”

fundamentals

6” 12” 12” 12” 1’-6” 1’-6”

types

1.2

PLANNING AND DESIGN

A steel column can span multiple stories, allowing for beams to be fastened at neccessary levels. Lateral bracing is used to support the columns. This minimizes structure, allowing for a more efficient parking garage.

8’-0”

25’-0”

SOURCES

1.1

INTROdUCTION

3.2 Enclosure

Strategies

fundamentals

Integrated Sitecast Concrete Railing The sitecast concrete railing is an enclosure

most often seen in the form of a half-height wall,

strategy which is still very much in use today,

which

however it is more often seen in older parking

creating opportunities for natural lighting and

structures and used less often in new construction.

ventilcation. The consistent use of concrete as a

In a sitecast concrete system using this enclosure

uniform matierial through the structure also serves

method, the shape of the railing is built of formwork

to create a unified aesthitic on the exterior facade.

and poured with concrete like all strucutral elements in the system. This creates a monlithic concrete structural element consisting of dropped beams,

SOURCES

PLANNING AND DESIGN

types

the floor slab, and the railing. This encloure type is

maintains an open enclosure system,

3.2 Enclosure Strategies

INTROdUCTION

Parking Garage: Planning and Design

SOURCES

The use of a singular element reduces the need for various connections and clips, as would be used in a precast concrete system. This removes any concern for such pieces weather or breaking.

PLANNING AND DESIGN

types

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals

Precast Concrete Spandrel One of the most commonly used enclosure

for daylighting and natural ventilation. This type of

straregies in structured parking is the precast

enclosure also creates the opportunity to add a new

concrete spandrel. A concrete panel is positioned

level of detail to a concrete facade.

between columns along the exterior of the building,

spandrel members may have inset panels with

creating a half-height wall around the perimeter.

decorative accents such as aggregated stone, or

The spandrel, being very basic in form, is in place to

the members may make use of different concrete

simply to keep both cars and pedestrians safetly

ad-mixtures to achieve varying pigments in the

within the building’s floorplate, and its low profile

concrete throughout the facade.

creates a boundary condition which allows for an

SOURCES

PLANNING AND DESIGN

types

open-enclosure structure, improving opportunties

Precast

INTROdUCTION fundamentals types

3.2 Enclosure Strategies

PLANNING AND DESIGN

Precast members can be assembled in various different ways.

The section on the left shows a precast spandrel member sitting on a slab and being pinned back to the structure through the face of the beam. On the right, a spandrel mamber is attached to the structure through connectors cast into the top face of the floor slab.

Parking Garage: Planning and Design

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals types PLANNING AND DESIGN SOURCES

Infill Wall A solid infill wall system is used when there is a

opportunities for natural lighting and ventilation. A

need to create an interior space with a higher

full height wall on the other hand can create a fully

degree of enclosure. Bricks or CMU blocks are

enclosed interior space, where glazed openings are

used to fill the space between structural columns

needed to allow for any natural lighting, and

around the perimeter of the floorplate. Depending

mechanical ventilation systems are used to circulate

on several issues, including safety, aesthetic, and

fresh air. An infill wall system may also act to brace

climate, this wall may be buit to various hights. A

the structural system against lateral forces. Since

wall built to a height of 4’ will be sufficient to safetly

this enclosure strategy is directly integrated with the

keep people and cars withing the building, while

structure it may also help to minimize load-bearing

also

elements elsewhere in the building.

maintaining

an

open

enclosure

with

INTROdUCTION fundamentals types

3.2 Enclosure Strategies

PLANNING AND DESIGN

A masonry cavity wall consists of two walls built into one system: a CMU backup wall, on the inside face of the opening, and a brick wall on the outside, with a 2� airspace inbetween. The brick wall is tied back across the airspace to the CMU backup wall for support, and any insulation or other necessary layers are placed withing the cavity.

Parking Garage: Planning and Design

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals

Non-Integrated Railing This railing type is independent of the primary

pedestirans within the floor plate. Other examples

structural system and similar to the integrated

of ths type include railings made up of steel tube

structural railing, it allows for an open-enclosure

members, or a combonation of steel members and

structure. In its simplest form this railing type is

steel cables. As an additive approach, this type of

made up of steel cables which span between

railing gives the designer freedom to introduce new

structural columns along the perimeter of the floor

elements. Incorporating new materials such as

plate. These cables are then placed under tension

steel railings or steel cables may also add a new

to stiffin them across the length of the span. This

level of detail to the design at a scale which is more

creates an edge condition with a minimal aesthetic,

closely related to the pedestrian.

SOURCES

PLANNING AND DESIGN

types

but which is sufficient to safetly keep both cars and

3.2 Enclosure Strategies

types

fundamentals

A steel railing needs to be properly secured to the structure of the building. This system is seated into boxes poured into the concrete, where steel angles attach the steel of the railing to the concrete.

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

1

SOURCES

PLANNING AND DESIGN

Steel cables are put into tension to add stability to the overall system. These cables may span between the structural columns, or between secondary steel members like seen here.

INTROdUCTION fundamentals types PLANNING AND DESIGN SOURCES

Glass Enclocure Glass

curtain

wall

excellent

Curtain wall systems can be designed to attach to a

opportunities to maximize daylighting and views,

building’s structure in several different ways. Often,

two things most often lacking in parking structures.

panes of glass and aluminum mullions are

By allowing daylight to penetrate the exterior wall

manufactured into unitzed panels which are simply

and reach deeper into the floor plate, the interior

hung from the edge of the floor slab. These panels

condition of a garage is transformed into a more

are also pinned back to the structure to help the

pleasant experience. The ability to have a clear

system resist lateral loads. Glass walls can also be

view beyond the envelope also allows pedestrians

built on the inside edge of the floorplate, enclosing

to maintain a visual connection to the exterior,

induvidual floors rather than wrapping an entire

further

facade.

improving

systems

the

create

interior

experience.

types

fundamentals

3.2 Enclosure Strategies

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Glass curtain wall panels may be hung from the primary structural system with steel angels or clips.

These connections may be attached either to the outer face of the floorslab or to the edge of the top horzontal face.

A glass enclosure may also be built within the same plane of the structural members, simialr to a ‘storefront’ system. The glass sits inside of aluminum extrusions which are cast into teh concrete floor slab. This could be used to create a fully enclosed interior space.

PLANNING AND DESIGN

2

SOURCES

1

INTROdUCTION

3.3

Economics

fundamentals

Above vs. Below Grade The decision to construct up or down when designing a structured parking garage is usually decided by a site’s size or shape. Most often, in

L4

dense urban environments, high real estate values result in small land plots, which drive the design underground. Because of the high costs

$16-25,000

L3

associated with excavation, especially when the water table is broken, underground garages are usually avoided if possible. In less dense, subur-

L2

$12-15,000

L1

$3,000

types

ban areas, niether demand for parking nor land value gives rise to the need for underground parking. In urban areas, however, high real estate costs usually lead to smaller plots of land, which often lend themselves to an underground structure. On top of this, retail and office space is

B1

The top half of this chart shows a parking garage with no option for future expansion. While the demand rises, the capacity cannot reflect this change. Revenue, therefore, levels out when demand finally meets capacity.

$30-60,000

reserved for the ground and upper levels, which is

SOURCES

PLANNING AND DESIGN

another reason for putting parking down below.

The price to construct a parking garage obviously varies based on structure type and materials, but

B2

$100,000+

also according to a few less obvious factors. Soil conditions, such as its density, stability, and moisture levels can also increase construction prices.

If construction descends below the water table

Figure 3.1.1. Cost per Parking Space for various

level, costs will reflect the volume of water which

levels of a structured parking garage. These costs

will be displaced, which often skyrockets the price

can vary depending on structure type, soil condi-

of a project.

tions, and water table level. Figures do not include engineering or financing considerations.

In the bottom half of the chart, a garage is shown that is designed with the possibility for future expansion. While costs will rise during years of future construction, the added revenue from capacity which reflects demand makes up for this discrepency. The result is a higher net provit value, even with added construction costs.

Parking Garage: Planning and Design

Designing for Future Flexibility

Type

Units 0

Demand Initial

Revenue

Cost

Cash Flow

$ in Millions

893

1,015

…

1,696

1,200

1,200

1,200

…

1,200

7.50

8.93

10.15

12.00

4.68 5.60

6.00

Actual

-26.34

1.50

2.93

4.15

6.00

6.24 Type

Units

Spaces

Actual

Year 2

3

…

20

1,141

1,234

…

1,598

800

800 200

1,000 200

…

1,800

8.00

8.00

10.00

15.98

3.60

5.20

4.26 5.20

4.68 5.60

7.20

-18.08

2.80

-1.46

-0.28

8.78

$ in Millions

Later Annual

1 1,055

Initial Added

Initial

NPV

750

4.26 5.20

Revenue

Cash Flow

20

6.00

Demand

Cost

…

22.74 3.60

0

Capacity

3

Initial Annual

NPV Category

Year 2

PLANNING AND DESIGN

Capacity

Spaces

1

14.48

7.57

SOURCES

Category

fundamentals

INTROdUCTION

3.3 Economics

types

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals

Regional Construction Cost

SF of stand alone structured parking, with no Construction costs vary regionally, depending on

basement. These numbers are based on the larg-

the structure type chosen for any given stand

est cities of each state, where structured parking

alone, structured, parking garage. Considering

is most typically used.

that structure accounts for 60-70% of the overall construction cost, this is a crutial initial decision which will affect the garage for the span of its lifetime. Variables that most directly affect this decision are cost, both initial and long term maintainance, time to build or procure, aesthetics, and availability of materials, which may change according to the local market. Generally, precast

types

concrete is favored in the Northeast, while reinforced, cast in place concrete is used in the Midwest. There are hundreds of structural options adn combinations available, but the most prevalent are the two aforementioned types, as well as a hybrid structural model which uses steel in combination with either type of concrete. Whichever PLANNING AND DESIGN

structure type is chosen, it is important to note its characteristics in terms of its durability, especially when dealing with harsh climates, specifically in the Northeast.

When building near the west

coast, near the fault lines susceptible to earthquakes, cast in place, post tension frame is often used, as it can handle the shifting loads more efficiently.

SOURCES

This diagram shows the construction cost per

Construction costs, regardless of structure type, tend to be most costly in large cities, where land value is highest. Variations from this trend are most likely due to the skill sets of the labor force, availability of material, or local market prices.

$48-58/SF $58-69/SF $69-80/SF Steel Frame, Reinforced Concrete Slab

$45-55/SF $55-65/SF $65-76/SF

fundamentals

Steel Frame, Precast Concrete Slab

types

3.3 Economics

INTROdUCTION

Parking Garage: Planning and Design

Reinforced Concrete Frame & Slab

$39-46/SF $46-53/SF $53-59/SF

SOURCES

Precast Concrete Frame, Reinforced Slab

PLANNING AND DESIGN

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

$34-41/SF $41-48/SF $48-54/SF

INTROdUCTION

Local Market Forces When a garage operator chooses a parking fee,

fundamentals

he trades off a larger market area with a lower fee against higher profit per customer with a higher

b=

w (fA - f O ) T + d 4v 2 2

Garage A’s market area = 2b

w = walking speed fA= fee per unit time for garage A fO= fee per unit time for other garages T = duration of parking v = value of time

fee. Customers will choose to park at the parking garage with the lowest full price. The full price is the sum of the parking fee per unit time, times the parking duration, plus the time costs of walking from the parking garage to the destination, and back again. In this case, time costs within the

B

b

parking garage are ignored. A driver is willing to pay a premium to park in a garage that is closer to

f <f

types

his destination since doing so reduces his walking

B

costs, which gives private parking garage operators market power. The result is a strategic interaction between parking garages, where each will attempt to anticipate the reactions of his competitors, the neighboring parking garages. A garage

A

A

f >f A

B

will ake into account that if it raises its fee sched-

SOURCES

PLANNING AND DESIGN

ule, its neighboring garages will be able to accomodate the diverted customers only to the extent

d

of their excess capacity; and similarly, if it lowers its fee schedule, it can absorb the extra customers generated only to the extent of its own capacity. Profits for any given garage will be a result of the difference between its land rent, height of

Changing Market Area when all competing park-

parking garage (number of storeys), and capacity

ing garages in a given area charge the same fee,

of garage as a function of its fee structure.

the market areas are diamond shaped. When the fees are different, however, the grids begin to mutate accordingly. (Arnott, Richard. Spatial Competition between Parking Garages and Downtown Parking Policy)

Parking Garage: Planning and Design

Above Ground 3+ Levels Below Ground ($50/SF Construction Cost) ($100/SF Construction Cost)

Land Cost/Space (Assumed at $20/SF)

$5,600

$850

Construction Cost/Space

$2,800

$16,000

$30,000

Subtotal

$8,400

$16,850

$30,000

$420

$2,400

$4,500

Project Cost

$8,820

$19,250

$34,500

Average Annual Debt Service (9% interest)

$1,200

$2,500

$4,200

$250

$1,000

$1,000

Total Annual Cost/Space

$1,450

$3,500

$5,200

Required Daily Income (260 Days/Year)

$5.50

$13.50

$20.25

Design & Contingency 15% (Construction)

Estimated Annual Operating Costs/Space

types

Surface Lot ($10/SF Construction Cost)

PLANNING AND DESIGN

Revenue Needed to Break Even

fundamentals

INTROdUCTION

3.3 Economics

SOURCES

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

INTROdUCTION fundamentals types

3.4

Ground Floor Planning

Interior spaces in parking garages need to be just

required to have a no-park zone 300 feet from the

Payment is also an important issue for parking

as secure as their entrance and exits.

Actual

terminal. This creates a dead zone in the most

garages. The Pay-on-Foot system revolutionized

safety and perceived safety are equally important.

used areas of existing garages and minimizes the

how users interact with the garage. At their most

Measures of safety include bright lighting, high

total number of vehicles that can park in the

basic form they are the new generation of metered

floor to ceiling heights, light or reflective paint, well

garage at once. New garages being built will have

parking. Some Pay-on-Foot systems use cashiers

planned entrances and exits, pedestrian-only

to take into consideration this new rule.

who are not located in booths along the garage

paths and the use of glass.

exit lane, but rather along a pedestrian walkway.

Once safety is achieved, way-finding is a key part

Other systems replace the cashier with a machine.

Lighting is used to keep users feeling safe and

of the user experience. This includes typical sig-

And some include both options.

reduce crime. Intense lighting layouts help the

nage and painted arrows and lines on the walls

speeds up the queue of vehicles exiting the park-

user, but can affect neighboring buildings, espe-

and floor. Before garages began using the self-

ing garage at the same time. This system is also

cially in the overnight hours; therefore great care

park system, way-finding did not exist. Physical

used as a pay and display centralized parking

needs to be taken in the design and placement of

orientation is key for the user in an unfamiliar

meter system for street parking. The latest tech-

lighting. Users may also feel uncomfortable due

parking garage. The user, while driving, needs to

nology allows users to pay by cell phone through

to the low ceilings, hanging structure which may

be directed where to enter, park, drive, and exit.

a service which gives each user a PIN to enter

block way-finding signs and lighting. The mini-

As a pedestrian the user uses way-finding to lead

when parking in designated parking garages.

mum illumination standard in a garage is in its

the way out of the parking garage and then back

parking area, which can be as low as 15 foot-can-

to the userâ&#x20AC;&#x2122;s vehicle.

dles of light. Typically areas with pedestrian traf-

SOURCES

PLANNING AND DESIGN

fic have higher levels of illumination

Pay-on-Foot

New parking garages are often built along with other new construction, for example a housing

New technological advancements in way-finding

complex, train station, or shopping center. For

include the electronic sign and internet updates

this reason the actual cost of parking is often sub-

Parking garage elevator and stair cores often are

on available spaces and parking garages.

sidized by other activities.

enclosed in glass which gives them a light open

Electronic signs can be placed at the entrance of

often subsidizes its parking, while private garages

feeling, instead of a concrete stair which seems

the garage to guide users to the easiest and quick-

are usually forced to charge the actual cost of

heavy and enclosing.

Technological advances

est available space. This system is known as

parking. This happens because without the nec-

such as this and others, the closed circuit televi-

â&#x20AC;&#x153;Smart Park.â&#x20AC;? These signs use real-time data to

essary parking to support new construction, it

sion, intercoms, and telephones, have given a

give accurate information. Internet updates allow

often will not succeed. The issue of parking is

new sense of security and perceived safety to the

user to check the parking availability before they

such a great one that cities often times have a

parking garage typology.

even leave home. The website gives recommen-

parking department that deals with everything

dations when a desired garage or lot is full.

involved with parking, including parking garages.

Special security concerns are now being used in

Advancements like these will continue to change

airport parking structures. Existing structures are

the way in which we park.

Public construction

3.4 Ground Floor Planning

Ground Floor essentials include proper egress, signage, elevator, and entrance and exit payment

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

stations. Optional first floor items include stanA ramp sytem lends itself well to having the exit and entrance located in close proximity to one another; this is due to the two-way traffic pattern.

The Yin-Yang booth arrangement allows for more

types

booths in each direction.

fundamentals

dard and handicapped parking spaces. The Type

Current standards require a stretcher-sized elevator to allow emergency personnel to access and assist users in the garage.

SOURCES

A mix of manned payment booths and monthly pass unmanned stations are most efficient for a mixed user facility.

PLANNING AND DESIGN

142â&#x20AC;&#x2122;-0â&#x20AC;?

INTROdUCTION

Many Parking Garages are not freestanding buildings and must accommodate other program on the ground level. This example shows the shortest ramp with parking to move the user away from

fundamentals

the ground level without encroaching of the space

types

that other program will occupy.

SOURCES

PLANNING AND DESIGN

107â&#x20AC;&#x2122;-0â&#x20AC;?

3.4 Ground Floor Planning

The speed ramp allows this ramp to be its shortest to give as much ground floor area to other pro-

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

gram uses. In this design payment booths are Foot before returning to their vehicles, eliminating manned booths in this parking garage.

57â&#x20AC;&#x2122;-0â&#x20AC;?

Pay-on-Foot stations located before a user returns to their vehicle allows for a parking garage to have less manned payment booths.

SOURCES

PLANNING AND DESIGN

types

fundamentals

located at the end of the ramp. Users Pay-on-

INTROdUCTION fundamentals types

3.5

Pedestrian Access

Minimum 5’-0” diameter wheelchair turning area

Provide a minimum of one elevator 7’-0” W X 4’-3” D to accomodate a 6’-4” L X 2’-0” W stretcher.

Ramps must be present along path of egress where a change in level occurs. Ramps can be a maximum of 1:12 slope for 30’-0” or less.

Provide guardrails that extend 1’-0” beyond top and bottom on either side of the ramp for ramps rising over 6” n height. The required minimum with of the ramp is 3’-0”

SOURCES

PLANNING AND DESIGN

Provide a clear opening of 2’-8” between leading edge of jamb and inside face of door when open 90 degrees. 2’-0” clear adjacent to latch side of door should be free and clear of obstructions. Rated doors and hardware is required.

3.5 Pedestrian Access

Provide at least one 2’-6”W x 4’-0”D area of refuge for a wheelchair per 200 occupants on a stair landing at the floor level that does not conflict with path of egress in an enclosed stairwell.

Handrails are required at 2’-10” above stair nosing on each side of stair and must not project more that 3” into pathway. Handrails must extend 1’-0” + the width of the tred past the bottom stair trd and extend 1’-0” past the top tred. Center handrail must be continuous.

Guardrails are only required on the non-walled side when stringers are separated greater that 1’-0.”

INTROdUCTION

Parking Garage: Planning and Design

fundamentals

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

Stairways must be a minimum of 4’-0” in width and landings must be a minimum of 4’-0” depth and match the width of the stair.

types

Stairs must be a minimum of 11” in depth measure from nose of tred to nose of tred and a maximum of 7” in height or a minimum of 4” in height.

Note 2: Refer to accessibility section for accessible stall sizes, adjacent clear dimensions and for required number of accessible parking stalls. All accessible parking stalls should be located as close to the core as possible and do not all have to be located on a single parking level.

Refer to standards for stall sizes Van accessible stalls can share 8’-0”W clear route adjacent to stall.

SOURCES

Note 1: A minimum of 2 accessible means of egress must be present on each parking tier for an occupant load of 1-500, 3 means of accessible egress for 501-100 occupants, and 4 means of egress for 1,001 or more occupants.

PLANNING AND DESIGN

Minimum 5’-0” wide passage aisle adjacent to the handicap parking stall must be free and clar of obstructions. For van accessible stalls a minimum of 8’-0” clear must be adjacent to the vehicle.

INTROdUCTION fundamentals types

3.6

User Behavior

PARKING INDUSTRY OBSERVATION STATES

tem. While a planner may be able to effectively

and distances between intermediate aisles, the

that driving behavior is susceptible to human

assess external demand, relative usage patterns,

driver experience is most affected by other drivers.

characteristics like any other activity. Parking

and many other quantitative data, the end user

Definite

garage users are creatures of habit, especially in

remains a moving target.

explored on this topic, but one can say that overall

daily-use scenarios. This condition dictates

PLANNING AND DESIGN

ramifications

can

be

driver behavior is directly affected by the design of

certain results, no matter how well the garage has

Whether or not a garage is turning away potential

the garage - there is a cascading effect from the

been designed. At the same time, this allows

parkers is critical not only to financial success, but

garage to users, and then between users over the

designers to formulate methods for designing

to the efficiency of circulation. A driver who does

course of any given day.

garages that can be accepted across the spectrum

not find a spot is a liability for the circulation sys-

of projects, though not every problem of human

tem, because they are then exiting during what is

For example, the amount of parking and unparking

behavior can be resolved.

probably a period of high volume of entering vehi-

movement in the garage is key to understanding

cles. While garages are typically planned around

driver behavior, especially in a ramp system with

The psychology of drivers varies, of course, for

a â&#x20AC;&#x153;design-dayâ&#x20AC;? scenario (using calculations based

one-way circulation. The design of the garage must

each individual, but there are some general obser-

upon demand during the 20th busiest hour of the

accommodate this, especially when considering

vations with respect to the users of the garage

year), the variability of human behavior may cause

the angle of parking, and the specific metrics of the

that are translated into graphic representation.

efficiency to break down even when the garage

stall. While a standardized Level of Service (LOS)

This set of quantitative measures revolve around

has not reached this capacity.

matrix can be attempted, it is not enough to simply

the dimensional characteristics of efficient garage

SOURCES

psychological

state that a particular size of stall or drive aisle will

design and the effect on driver movement. These

Taxonomy of Driver Behavior

are performative characteristics that drivers must

This first set of diagrams illustrates general differ-

involuntarily obey in order to reach a certain desti-

ences in vehicle behavior across a range of

For all the exercises contained herein, a garage

nation within the garage.

garage ramp types.

capacity of 85% was used to determined the vehi-

It is important to keep in mind that parking garage

There are a number of metrics that are not shown

because studies have shown that drivers perceive

design is a complicated parametric exercise.

in these diagrams, but can be drawn from the

a garage as full when in fact it is only at 85% of its

Modification of one dimension will affect more

information presented. While there are certain

design capacity.

than one other component of the circulation sys-

industry standards for the length of the main aisles

facilitate a particular turnover ratio.

clesâ&#x20AC;&#x2122; destination. This benchmark was chosen

3.6 User Behavior Familiar & Visitor

15 Left

+70’-0”

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

85%

fundamentals

14 Left

13 Left

+60’-0” 12 Left

11 Left

9 Left

types

8 Left

7 Left

+40’-0”

10 Left

+50’-0”

Type A - Two-way single helix

6 Left

5 Left

+30’-0”

This circulation system provides a straightforward and efficient method of parking. There are minionly two turns on each floor. A two-way drive aisle allows a safer route for pedestrians, but more 1 Left

2 Left

dangerous corners for drivers because of oncoming traffic on a downhill slope. While the organiza-

+10’-0”

tion groups familiar and unfamiliar drivers on the same path, the two-way traffic movement and related metrics ease congestion. However, this

PLANNING AND DESIGN

3 Left

mal turns for a garage of this size - technically

4 Left

+20’-0”

does not guarantee quick access to the vacant

+10’-0”

means that slow traffic or a high rate of parking/ 3,800

3,600

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 feet

unparking cannot be bypassed.

SOURCES

stalls: the combination of ramp and parking deck

INTROdUCTION

Type B - Central two-way ramp This ramp type, described in detail in a case study later in this chapter, is fairly convoluted. The oneway traffic pattern makes it difficult for visitors,

fundamentals

meaning that drivers searching for an empty stall need to recirculate and overlap their path prior to continuing on to the next level. Because of this, the garage may actually become a Level of Service (LOS) “B” type because so many stalls are passed. In the course of doing so, there are an exceptional number of turns, creating disorien-

types

Visitor

29 Left 28 Left

27 Left

26 Left

25 Left

24 Left

23 Left 22 Left 21 Left 20 Left

19 Left

18 Left

13 Left 12 Left

11 Left

9 Left

10 Left

8 Left

7 Left 6 Left

5 Left 4 Left

2 Left

PLANNING AND DESIGN

33 Left

85%

17 Left

16 Left

15 Left 14 Left

9 Left 8 Left

7 Left 6 Left

1 Left

3 Left

3 Left 2 Left

5 Left 4 Left

1 Left

+20’-0”

85% 13 Left 12 Left

11 Left 10 Left

+30’-0”

32 Left

31 Left 30 Left

+40’-0”

Familiar

access once they have parked.

17 Left

well as locating their intended pedestrian exit

16 Left

15 Left 14 Left

tation for the driver in terms of finding a stall, as

+10’-0”

3,800

3,600

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 feet

SOURCES

+10’-0”

3.6 User Behavior

Type C - One-way double helix 7 Left

8 Right

This type is often considered the most difficult to

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

understand for a driver. Two interlocking one-way helices, one up and one down, do not lend them-

9 Right

10 Right

6 Left

5 Left

+60’-0”

are that a visitor will want to check all spots on the way to the target, this system requires the driver to actually summit the top of the garage and begin the return path in order to locate a vacant stall.

With prior knowledge of the crossovers in between

fundamentals

selves to ease of use for a visitor. Assuming as we

helices, a driver can reach the destination in about

+50’-0”

20% of the visitor distance. If the garage is used 12 Right

tem functions much in the same way as Type A,

+40’-0”

and is very efficient. The one-way travel can 4 Right

3 Right

cause congestion as expected, but the crossovers

1 Left

2 Left

1 Left

2 Left

provide a bypass method, unlike Type A.

types

11 Right

4 Left

3 Left

accordingly, even for all available stalls, this sys-

Familiar

Visitor

+20’-0”

85%

85%

+10’-0”

PLANNING AND DESIGN

+30’-0”

SOURCES

4,600

4,400

4,200

4,000

3,800

3,600

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 feet

+10’-0”

INTROdUCTION fundamentals

Type D - Split-level This ramp type is very similar to Type A, except

dangerous to pedestrians and other drivers alike

that all the parking decks are level. Best suited for

because there is little visibility. This can be espe-

a long, narrow site, the short ramps avoid struc-

cially problematic with two-way ramps. For unfa-

tural problems of longer slopes and, when placed

miliar drivers, locating a vacant stall can be

frequently, offer a method of bypassing conges-

difficult because they do not have a clear view

tion. However, the frequency of ramps means a

across the entire width of the building - if anything

reduction in parking stalls, as well as the expense

they will have a view of the deck from which they

of an additional ramp. Doubling the ramps and

have just come.

16 Left

individual parking decks also increases the overall cost. Ramp locations, while convenient, can be

Familiar & Visitor

15 Left

14 Left

13 Left

12 Left

+40’-0”

85%

types

11 Left

10 Left

9 Left

8 Left

+30’-0”

1 Left

PLANNING AND DESIGN

7 Left

6 Left

5 Left

4 Left

3 Left

2 Left

+20’-0”

+10’-0”

5,800

5,600

5,400

5,200

5,000

4,800

4,600

4,400

4,200

4,000

3,800

3,600

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 feet

SOURCES

+10’-0”

Type E - Express ramps The main feature of this type, the externalized

with no parking stalls, also introduces the issue of

be efficiently designed for the driver. The require-

clearway ramp, provides a straightforward bypass

additional initial cost to the garage owner and

ments for the length of the external ramp mean

to slower traffic and uncertainty of a large, circu-

space that does not generate revenue. At the

that the garage has a very broad footprint, and

itous parking deck. However, the level access

same time, the separate bypass circulation

this in turn will create a situation where numerous

lane for clearway travel exposes drivers to poten-

reduces risk to pedestrians because they are not

turns are required. For an unfamiliar driver, this

tial conflict, especially because the aisle passes

required to walk on a sloped surface with moving

sea of parking can be daunting and frustrating.

numerous locations where searching drivers are

vehicles beside them. Aside from the clearway

turning, in both directions. The separate ramp,

ramp, the interior of the garage inherently cannot 23 Left

22 Left

21 Right

20 Right

Visitor

Familiar

19 Right

8 Left

7 Right 6 Right

5 Left 4 Left

85%

85%

1 Left

types

18 Right 17 Right

16 Right

15 Right

14 Left

13 Left

12 Right

10 Right

11 Right

3 Right 2 Right

+20’-0”

fundamentals

3.6 User Behavior

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

+10’-0” 9 Right 8 Right

7 Left

6 Left

5 Left

4 Right

3 Right

2 Left

1 Left

Type A Two-way single helix Type B Central two-way ramp Type C One-way double helix Type D Split level Type E Express ramp

5,200

5,000

4,800

4,600

4,400

4,200

4,000

3,800

3,600

CONSECUTIVE 360º TURNS

Familiar

Visitor

Familiar

Visitor

AVERAGE DISTANCE BETWEEN TURNS (FT)

(1)

15

15

4

4

50

.432

17

33

4.5

9

90

4

12

0

3.5

186

(1)

16

16

4

4

179

.314

8

23

1

1

114

NUMBER OF TURNS

PLANNING AND DESIGN

RAMP TYPES

EXPRESS FACTOR

SOURCES

Ramp Type Comparative Analysis

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 feet

+10’-0”

INTROdUCTION fundamentals types

A Case Study in User Behavior: Princeton University Parking Structure Drivers have fundamentally different experiences,

users begin to go home. Traffic levels are main-

especially in parking structures where there is a

tained as this exit pattern is balanced by an

mix of nearby program. At Princeton, there are a

entrance pattern of students. Also typically famil-

few basic groups of customers: faculty, staff, stu-

iar users, students make use of the bottom-to-top

dents, and visitors.

vacancies.

Faculty and staff are typically the biggest segment

Throughout any given day and for some special

of familiar visitors, arriving earliest in the day. At

occasions, the garage may be used by authorized

this point, vacancies are arranged top-to-borttom,

off-campus visitors: they are the unfamiliar oppor-

and are located mostly away from the pedestrian

tunists following the longer circulation pattern

circulation cores (which include the exits). Though

shown later in this section. For these users, way-

the garage is open around the clock, it is reserved

finding is critical. The Princeton garage is outfit-

between the hours of 8:00 am and 5:00 pm for

ted with directional arrows on the driving surface

university employees. During this period, the

as well as various columns at the corners and the

usage increases dramatically in the first couple

entrance and exits of the ramp. There are numer-

hours, then plateaus for the majority of the day,

ous floor-level indicators to help drivers remember

seeing some activity during the lunch hour. The

where their vehicle is parked, and also to direct

rate of vehicle movement increases as the end of

them to exits, stairs, and the elevator.

the business day approaches, and faculty/staff

SOURCES

PLANNING AND DESIGN

Project Data Location: Princeton University Engineering Quad, Princeton, NJ Dates of construction: 1988 - 1991 Architect: Machado & Silvetti Architect-of-record: Peter Longren Consultants: Lim Consultants, Inc. (structural); Cosentini Associates (mechanical); Van NoteHarvey Associates (site); Berg/Howland (lighting) Construction type: Steel frame w/ concrete deck Building Area: 165,080 GSF Number of stalls: 403 391 faculty/staff; 9 accessible; 3 reserved.

291 full-size (9’-0” x 19’-0”) 112 compact (7’-8½” x 16’-6”) Parking stall-area ratio: 38.7% (64,006 SF) Area/stall: 410 SF Ramp-area ratio: 7.8% (12,895 SF) Drive aisle-area ratio: 34.8% (57,500 SF)

Locating exit-access is a component of the user experience that affects where drivers will eventually park: they may even go to the next level of the garage in order to find a vacant stall adjacent to a pedestrian exit.

In addition, the no-charge operation of the facility provides some alleviation to high volume periods of use because there is no delay for taking a ticket or making a payment. This allows vehicles to enter the circulation path immediately, which is a measure of efficiency; however, because of this, there is a potential for conflict with vehicles that are recirculating on the ground floor.

Top: View of garage exterior Middle: View of ramp system. This image illustrates one possible negative factor for users: a dim, foreboding interior that does not evoke a feeling of security.

Bottom: Typical parking deck. In addition to a feeling of relative lack of safety and overhead clearance, this view shows another negative factor for drivers: a bright exterior view at the end of a much darker drive aisle. This is distracting at the least, and can cause safety issues.

User Density and Location

8:00AM

Entering

Student users

Exiting

The morning rarely sees any outbound traffic. All users are faculty/staff, and the garage fills from bottom to top, and from the pedestrian exits toward the center.

The garage continues to fill throughout the morning. Some vacancies occur as users run errands, or go about other business on campus.

types

10:00AM

(Volume of traffic)

Faculty/staff users

fundamentals

3.6 User Behavior

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

6:00PM

Most of the faculty/staff users are leaving for the day, except perhaps for those performing after-hours services, such as janitorial staff. After 5:00pm, students make up the majority of entering vehicles.

PLANNING AND DESIGN

3:00PM

The garage reaches its highest density for the day, as late-arriving users populate many remaining spots. However, some of the early-morning users have already begun to leave.

SOURCES

12:30PM

Widespread and random vacancies occur during the lunch hour. There is no pattern, however the empty stalls are still re-filled with only faculty/staff vehicles.

INTROdUCTION fundamentals types PLANNING AND DESIGN

Visitor

85%

Level of Service A

9 Left 8 Left

7 Left 6 Left

4

5 Left 4 Left

3 Left 2 Left

+10’-0”

85%

30 4

1 Left

+20’-0”

8 29

13 Left 12 Left

11 Left 10 Left

+30’-0”

30

Familiar

7

17 Left

+40’-0”

16 Left

15 Left 14 Left

Figure 3.6.6_Familiar user metrics

7

7

30

(See following spread for detailed Visitor graph)

3,600

3,400

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

30 4

600

7

400

0 feet

SOURCES

2

200

+10’-0”

3.6 User Behavior Princeton Parking Structure Familiar Driver Analysis

Number of turns

For drivers familiar with the garage, the number of turns can become a robotic habit day after day; therefore an anomaly in the circulation can cause significant congestion from their perspective. Because of familiarity and individual habits, the number of turns does not become disorienting, because the driver is targeting a specific level or location with respect to pedestrian circulation cores.

The entry sequence for the garage is straightfor-

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

ward for a veteran user: only one turn is required daytime users - faculty and staff - arrive early in the morning, the first level is going be full first.

This is not an unexpected phenomena in parking garages - the earliest users will migrate towards Entry path for familiar drivers (Level 1)

360Âş turns

Conventional garage design suggests limiting the number of complete rotations to five or six, which thus set parameters for the ramp design and overall height of the garage. Due to the one-way circulation and ramp position, this garage can be problematic (see next spread). However, familiar drivers are able to bypass roughly half the parking deck area and so reduce the number of complete rotations proportionately to five.

the closest exits in the direction of their final

fundamentals

to access the central ramp. Given that the primary

destination.

The steel construction of the garage allows drivers to see most of the stalls in the garage while garage, a familiar driver can tell whether or not skipping the next turn up the ramp will be worth-

types

moving up the ramp. Given the capacity of the

while. For a familiar driver interested in a quick exit, the extra time driving may be valuable because there are stalls available close to the Central path for familiar drivers (Typical Level: 2-4)

be encountered during afternoon rush hour if the driver chooses a spot opposite the â&#x20AC;&#x153;downâ&#x20AC;? ramp.

Stalls passed

A driver needs to assess parking location with

The number of stalls this driver passes is not critical to their circulation, because they are familiar with the everyday patterns of parking. Because certain locations fill up first, especially adjacent to the pedestrian circulation cores, this driver targets known areas of vacancy. Free stalls along this path are infrequent and not expected - with this mentality, the driver operates virtually in a higher Level of Service, and no stall is passed twice.

regard to their destination - parking for ease of exit may mean a longer period walking, a consequence affected by weather and pedestrian

PLANNING AND DESIGN

vehicle exit circulation. Possible congestion may

safety. Faculty or staff used to this garage will out these factors.

End of path for familiar drivers (Level 5)

SOURCES

have a preferred location that most likely balances

3,600 3,400 3,200 3,000 2,800 2,600 2,400 2,200 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400 200 0 feet PLANNING AND DESIGN types

fundamentals

Visitor

SOURCES

33 Left 32 Left 31 Left 30 Left

24 Left

25 Left

26 Left

27 Left

29 Left 28 Left

29 23 Left 22 Left 21 Left 20 Left 19 Left 18 Left 17 Left 16 Left 15 Left 14 Left 13 Left 12 Left 11 Left

9 Left 8 Left 7 Left 6 Left

5 Left 4 Left 3 Left 2 Left

30 7 27 2 30 12 4

7 30 4 30 5 7 8 1 Left

+10’-0”

7 30 4 30 5 7 8 30 10 Left

+20’-0”

30 4 30 5 7 8 30 See Figure 3.6.11

+30’-0”

85% 8 30 7

85% (See previous spread for detailed Familiar graph)

+40’-0”

Familiar

INTROdUCTION

Figure 3.6.7_Unfamiliar user metrics

Level of Service A

+10’-0”

Parking Garage: Planning and Design

Number of Turns

Princeton Parking Structure Visiting Driver Analysis

For an unfamiliar driver, the sheer number of turns necessary in the search for an empty parking stall is a true indicator of garage efficiency. This translates into average speed, and so also the amount of time it takes a visitor to reach an empty stall. This is compounded by the one-way circulation, which means that the visitor will have to make extra turns to locate a vacancy.

For a driver not used to this garage, it will initially

INTROdUCTION

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

be somewhat confusing because of the one-way are looking for the best location possible, it is necessary to drive around the ground floor before heading to the next level. Of course, this will then in turn slow down other traffic parking or unparkEntry path for unfamiliar drivers (Level 1)

ing on that floor. Typically, drivers entering a

fundamentals

direction. The driver will soon discover that, if they

garage move more efficiently because they only require the first available stall. But a visitor will

360ยบ turns

Because the visitor will be expecting to find a free stall by searching ALL the stalls in the garage, the number of complete turns is nearly twice that of the familiar driver.

This can result in disorientation for the driver because their direction changes so often. Landmarks and signage are critical in garages with a circulation system that is not intuitive. At Princeton, the central ramp becomes a landmark for drivers.

drive slower, or wait longer for a stall, and thus cause congestion that familiar users do not

In the typical levels of parking, the circulation gets

types

expect.

more complicated: the visitor will pass some stalls more than once, which is good for accessing available stalls, and that is in the interest of this effect on circulation because the driver is on that level for longer, and their re-circulation interferes with vehicles entering and exiting the central

Stalls passed

ramp.

The visiting driver can also be affected by the structure of the garage: a low floor-to-floor height can be discouraging and somewhat claustrophobic. It can also be uncomfortable for pedestrians, because the light fixtures are mounted between steel beams - this creates a dimmer interior which can translate into a feeling of insecurity.

End of path for unfamiliar drivers (Level 5)

SOURCES

To a driver unfamiliar with the garage, every stall is a possibility - the relative turnover rate is not apparent. Therefore any location is an opportunity for vacancy, and more like than not the visitor will attempt to cover the area of the garage as thoroughly as possible in order to find an empty stall. The driver believes that the garage must have free stalls, therefore free stalls ARE expected.

The one-way circulation requires the driver to then pass some stalls twice, which while increasing the opportunity for finding a vacancy, lengthens the time spent searching and so lowers the Level of Service.

PLANNING AND DESIGN

type of driver. However, this will have a negative Central path for unfamiliar drivers (Typical Level: 2-4)

02:30

02:00

01:30

01:00

00:30

05:30

05:00

04:30

04:00

3,600

3,400

3,200

08:00

07:30

07:00

3,000 06:30

2,800 06:00

2,600

2,400

2,200

2,000

1,800

1,600 03:30

1,400 03:00

1,200

1,000

800

600

400

200

0 feet 00:00

types

fundamentals INTROdUCTION

Visitor

PLANNING AND DESIGN

Familiar

9 Left 8 Left

7 Left 6 Left

5 Left 4 Left

3 Left 2 Left

SOURCES

17 Left

13 Left 12 Left

11 Left 10 Left

Turning

+10’-0” 1 Left

+20’-0” Relative MPH

16 Left

Cruising

+30’-0” Bypassing

+40’-0”

15 Left 14 Left

Figure 3.6.8_Familiar user characteristics

85% 85%

(See following spread for detailed Visitor graph)

+10’-0”

3.6 User Behavior Qualitative Driver Experience Analysis - Familiar

Turns and circulation

The turns indicated are directly related to overall traffic movement, because every driver does not turn at the same rate. For the familiar class of drivers, entering the garage at a time of day when many spaces are sequentially available, the turns may not present much of an obstacle because all the cars are moving in the same direction; for example, in the morning, no cars are backing out, so vehicles can move around the corners faster.

Frequent turns affect other aspects of the parking

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

experience, explicitly the time required to find a they need to slow down to perform the maneuver, as well as check for pedestrian traffic. This is why garages are typically designed (here as well) to move one-way vehicular traffic in a counter-clockEntry path for familiar drivers (Level 1)

Vehicle speed

wise direction: the driver has a wider view of the

fundamentals

free stall. Each time a driver has to make a turn,

aisle ahead, not obstructed as much by structure or other parked vehicles.

Bypassing, which in this case refers to vehicles on the ramp where there is no parking capacity.

For a familiar driver, the turning like all other faclike clockwork. The experienced driver is able to enter and exit the turn in a much smoother man-

Turning, the slowest speed, during which the driver is confronted with possible blind spots (see above);

types

tors becomes a mechanical movement, almost

Cruising, where the driver is looking for a stall along the main parking aisles;

ner than a visitor, and is not distracted by views to the exterior. In fact, because they are used to performing an upcoming turn, familiar drivers are Central path for familiar drivers (Typical Level: 2-4)

ing level or aisle. Because of this, the driver may have the ability to shorten or widen turns in order to access a free stall. However, there may be a

Time

few moments when the driver is perusing adjacent

It is difficult to determine an acceptable time of travel for any given circulation. This study assumes an average speed of five miles per hour (5 MPH) for the driver. A more detailed study of a vehicleâ&#x20AC;&#x2122;s path would show compression and expansion of time measurement related to various reductions in interfloor circulation.

aisles that may be dangerous for pedestrians.

SOURCES

Using this speed, a ride to the top level of the garage would just under four (4) minutes. This has been confirmed in the field.

PLANNING AND DESIGN

able to look ahead to stalls that are on the upcom-

End of path for familiar drivers (Level 5)

3,600 3,400 3,200

08:00 07:30 07:00 3,000 06:30

04:00

04:30

05:00

05:30

2,800 06:00 2,600 2,400 2,200 2,000 1,800 1,600 03:30

00:30

01:00

01:30

02:00

02:30

1,400 03:00 1,200 1,000 800 600 400 200 0 feet 00:00

Turning

types

PLANNING AND DESIGN

+30’-0” fundamentals

Visitor

Bypassing

Cruising Cruising

SOURCES

33 Left 32 Left 31 Left 30 Left 29 Left 28 Left 27 Left 26 Left 25 Left 24 Left 23 Left 22 Left 21 Left 20 Left 19 Left 18 Left 17 Left 16 Left 15 Left 14 Left 13 Left 12 Left 11 Left 10 Left 9 Left 8 Left 7 Left 6 Left 5 Left 4 Left 3 Left Relative MPH

+10’-0”

Familiar

+40’-0”

2 Left

+10’-0”

1 Left

+20’-0”

85% (See previous spread for detailed Familiar graph)

85%

INTROdUCTION

Figure 3.6.9_Unfamiliar user characteristics

3.6 User Behavior Qualitative Driver Experience Analysis - Visitor

Turns and circulation

A circulation path requiring a substantial number of turns for an uninitiated driver can cause frustration, meaning the driver either attempts to exit the garage, or severely slows other traffic. Signage or pavement markings directing visitors to separate levels and pedestrian exists can alleviate this issue. Though not present at Princeton, some garages employ an electronic system that directs users to free stalls.

Excessive turning can be a direct psychological

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

burden to a driver. Besides the possible disorienthe change in direction may often present a driver with a new view to the exterior. In a garage such as Princeton, with an elaborately designed external fenestration, this can be problematic.

Entry path for unfamiliar drivers (Level 1)

fundamentals

tation of a driver when completing 360ยบ rotations,

Simply having openings to the exterior can be the

Vehicle speed

cause for accidents: a sunny day can make visibil-

Bypassing, which in this case refers to vehicles on the ramp where there is no parking capacity.

ity very difficult in the garage, because the majority of the garage is lit artificially (especially the

Given the one-way circulation, when exiting the ramp, vehicles must turn immediately after facing an opening, and then turn again shortly after. All physical metrics aside, the difficulty of making the lighting.

Another characteristic of the garage that may slow

Time

down unfamiliar drivers is the ramp system itself.

Optimistically assuming the same average speed as the familiar driver, this circulation path takes nearly twice as long.

The Princeton garage employs a three-part ramp: the steepest 50% is in the center, with two shallower sections at the top and bottom to minimize

PLANNING AND DESIGN

actual turn can be compounded by the contrast in Central path for unfamiliar drivers (Typical Level: 2-4)

damage to vehicles in the transition between flat deck and sloped. Consequently, the ramp is also assumed to be less psychologically imposing to the unfamiliar driver. However, the location of the ramp around a corner in every case poses an End of path for unfamiliar drivers (Level 5)

obstacle to the velocity of the unfamiliar driver.

SOURCES

Turning, the slowest speed, during which the driver is confronted with possible blind spots (see above);

bright opening can temporarily blind a driver.

types

ramp). Emerging into an aisle confronted by a

Cruising, where the driver is looking for a stall along the main parking aisles (this displays multiple speeds depending on the length of the aisle - a more detailed study could show the affect of parking or unparking vehicles);

02:30

02:00

01:30

01:00

00:30

05:30

05:00

04:30

04:00

08:00

07:30

07:00

fundamentals

85%

3,600

3,400

3,200

3,000 06:30

2,800 06:00

2,600

2,400

2,200

2,000

1,800

1,600 03:30

1,400 03:00

1,200

1,000

800

600

400

200

0 feet 00:00

types

PLANNING AND DESIGN

Turning

+10’-0” Bypassing

Cruising

+10’-0”

INTROdUCTION

(See previous spreads for detailed graphs)

Visitor

Turning

SOURCES

Cruising

+20’-0” Bypassing

+40’-0” Familiar

Figure 3.6.10_Potential circulation conflicts

85%

+30’-0”

Relative MPH

A location in the garage where the flow of familiar drivers may interact with that of unfamiliar drivers. Typically this is when one flow of traffic is exiting the ramp into another.

Two-path internal conflicts This is an instance where the re-circulation of unfamiliar drivers overlaps - drivers exiting the ramp confront other unfamiliar drivers who have already circulated around the deck.

separated for clarity. But it is reasonable to

conflict is possible at the entrance to the garage.

assume that both types of drivers are present in

Because of the one-way circulation pattern, such

the garage at any given time. Therefore the flow of

conflict is unavoidable throughout the garage. The

each circulation type will come into contact with

potential for an accident is exponentially increased

the other, and given the characteristics of each

when one considers that unfamiliar drivers may

described in this study, it is important to map

turn in the wrong direction at the top or bottom of

potential conflicts.

the ramp, making signage or pavement markings critical to smooth operation.

While there may be congestion related to differing speeds of travel, those are not calculated here

Because of the circulation pattern, an interaction

because their location is variable. Unfamiliar driv-

between the two types of drivers would probably

ers may in fact be driving slower on Prospect

result in assuming the characteristics of the slower

Avenue if they are visiting campus for the first

type, the unfamiliar driver. It is less likely that a

time.

visitor will speed up to match more experienced

types

Two-path external conflicts

part, this is centered on the ramp, although some

drivers in a technical environment such as this, The remaining potential for conflict, and that is

while faster drivers will have no choice but to slow

conflict which is physical, clusters about the

down for a new user.

Ground level plan showing one internal and one external conflict, both of them two-way.

This is caused primarily by the entry.

Typical level plan showing all three types of conflict, occurring exclusively at the entry and exit points of the ramp.

PLANNING AND DESIGN

A location in the garage where the flow of familiar drivers may interact with that of two paths of unfamiliar drivers.

changes in direction and elevation. For the most

familiar and the unfamiliar diagrams have been

SOURCES

Three-path conflicts

In the methods of study presented thus far, the

fundamentals

Interfloor Circulation Conflicts

INTROdUCTION

Parking Garage: Planning and Design

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

SOURCES

Vehicles slowing to ascend ramp

RECIRCULATION

PLANNING AND DESIGN

MORN ING V OLUM DAYT E IME V O LUME EVEN ING V OLUM E types

fundamentals

21 Left

5 7

Traffic slowing for unparking vehicle

Conflict at vehicles exiting ramp

30

20 Left

19 Left

18 Left

17 Left Vehicles slowing to ascend ramp

VEHICLE SPEED

4 8

30

87’-4”

139’-6” 52’-10” 139’-6”

STALLS PASSED

16 Left

Decelerate in to turn Maximum 22’-10’ radius Check for pedestrians Check signage Scan for vacant stalls Slow for car turning Accelerate out of turn

INTROdUCTION

Figure 3.6.11_Factors affecting behavior

87’-4” DISTANCE TRAVELED

RECIRCULATION

Comprehensive Metric Analysis

This diagram shows all the factors affecting driver

Parking Garage: Planning and Design INTROdUCTION

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

types

fundamentals

behavior in the parking garage.

Quantitative measurements that determine Level of Service (LOS).

PLANNING AND DESIGN

Unpredictable circulation reductions.

Affected by: Parking stall dimensions Drive aisle width

Typical vehicle speed - drivers are searching for vacant stalls.

SOURCES

Recirculating vehicle speed - drivers accelerate because they have already passed these spaces.

Sources

Allen, Edward, and Joseph Iano. The Architectâ&#x20AC;&#x2122;s Studio Companion. Hoboken, NJ: John Wiley and Sons, 2002

INTROdUCTION

Parking Garage: Sources

ar c G 6 9 1 t y p o l og y pat t e r n b o o k

2007 Chrest, Anthony P., et al. Parking Structures 3rd ed.New York: Springer Publishing, 2001 Jackle, John A., and Keith A. Sculle. Lots of Parking: Land Use in Car Culture. Charlottesville: University

fundamentals

American Institute of Architects. Architectural Graphic Standards. Hoboken, NJ: John Wiley and Sons,

of Virginia, 2005 Klose, Dietrich. Metropolitan Parking Structures. New York: Frederick A. Prager Publishers, 1966

Transportation, 1990

types

Weant, Robert A., and Herbert S. Levinson. Parking. Washington, DC: Eno Foundation for

Mc Donald, Shannon Sanders. The Parking Garage: Design and Evolution of a Modern Urban Form.

Urban Land Institute, 2007

SOURCES

Stadig, Arthur. Personal Interview. 22 Oct. 2008.

PLANNING AND DESIGN

Urban Land Institute, National Parking Association. Dimensions of Parking. Urban Land Institute, 2000

SOURCES

PLANNING AND DESIGN

types

fundamentals INTROdUCTION

Decelerate in to turn aximum 22’-10’ radius Check for pedestrians Check signage Scan for vacant stalls Slow for car turning Accelerate out of turn

21 Left

20 Left

19 Left

18 Left

ARCH G691 GRADUATE DEGREE

17 Left

16 Left

PARKING

RECIRCULATION

PROJECT STUDIO FALL 2008 This publication has been prepared as part of a five week graduate thesis studio assignment in the Northeastern University School of Architecture for the Fall 2008 Architecture G691 course. Other publications and self storage typologies, all produced by graduate students in the Northeastern

87’-4”

139’-6”

87’-4”

8

30

5 7

Vehicles slowing to ascend ramp

VEHICLE SPEED

Conflict at vehicles exiting ramp

STALLS PASSED

Vehicles slowing to ascend ramp

DISTANCE TRAVELED

Traffic slowing for unparking vehicle

University architecture program.

MORN ING V OLUM DAYT E IME V O LUME EVEN ING V OLUM E

in this series include urban retail, hotel,

139’-6” 52’-10” 30

4