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