OFF STREET PARKING REQUIREMENTS
Greiner Enginecrinu SClence~, lnc
5601 Manner Stn~et "P.O Box 23646
Tampa, Florida 33623
8n879-1711
TWX 810-876-4144
Coble GREINCO-Tampa
Greiner Environmental
5105.3100
October 2, 1981
Mr. Carmen S. Annunziato
City Planner
City of Boynton Beach
120 Nothteast 2nd Avenue
Boynton Beach, Florida 33435
Dear Mr. Annunziato:
Reference:
Off-Street Parking Requirements
Enclosed herewith are five (5) copies of our report which
compares the City of Boynton Beach off-street parking requirements
with those generally utilized for large scale retail developments,
and which we propose for use in the Boynton Beach Mall project.
In our last conversation, you indicated that the City may wish
to consider amending its off-street parking regulations if it was
deemed to be appropriate. With that in mind, we have attempted
to provide sufficient information in this report to assist the
City in evaluating the impact of such a change. One possibility
which the City may wish to consider is the establishment of
separate requirements for large parking areas. This would allow
continuation of the current standards for small individual pro-
jects, but would provide the flexibility to minimize total imper-
vious cover in projects which exceed a certain threshold to be
established by the City.
In addition to our report, I am also including a copy of
Dade County's most recent off-street parking ordinance which
includes provisions for compact car spaces. Although we do not
advocate this practice, I think that you will find it interesting
in comparison to some of the arguments for and against this
practice,included in the articles in the Appendix of our report.
In addition, I would like to point out that their standard space
has a maximum 9-foot width and is similar in other dimensions to
that which we propose for use at Boynton Beach Mall.
"
Greiner Environmental
Mr. Carmen Annunziato
Boynton Beach, FL 33435
-2-
October 2, 1981
We would be happy to meet with you and other representatives
of the City of Boynton Beach, at your convenience, to discuss
the information included in our report and the proposed parking
standards that we have recommended. Should you have any questions
regarding any of the information, please do not hesitate to
contact me.
Yours truly,
GREINER ENVIRONMENTAL
~~---
r
Thomas A. Marsicano
TAM:tef
Enclosures
cc: Mr. David H. Curl
Mr. Robert Schreiber
Mr. John Moyle
1
Amended
Substitute
Agenda Iter:-.
10-21-80
bU -ll{j
No. 2 (a)
ORDINANCE NO.
80-116
ORDINANCt REPEALING SECTION 33-122 (REQUIRED
DEFINITIONS OF PARKING SPACE) OF THE CUDE OF
METROPOLITAN DADE COUNTY AND ENACTING A NEW
SECTION 33-122 CHANGING STANDARD PARKING
SPACE DIMENSIONS AND AISLE WIDTH; ADDING
DEFINITIONS AND DIMENSIONS FOR.COMPACT CAR
AND HANDICAPPED CAR SPACES; DEFINING CONDITIONS
AND STANDARDS FOR THEIR INCORPORATION; ADDING
A MINU'IUM PARKING STALL DIHENSIONS CHART AS
AN ADDENDUM THERETO; AND PROVIDING INCLUSION IN
THE CODE, SEVERABILITY AND AN EFFECTIVE DATE
WHEREAS, the B6ard is aware of the need to .improve the
efficient use of land; and
WHEREAS, the Board recognizes the ever increasing ratio of
compact cars on the road.and that their accommodation encourages
their use and the conservation of energy,
NOW, THEREFORE, BE IT ORDAINED BY tHE BOARD OF COUNTY
COMMISSIONERS OF DADE COUNTY, FLORIDA:
Section 1.
Section 33-122, Code of Metropolitan Dade
County, Florida, is repealed in its. entirety and a new Section
33-122 is hereby enacted as follows:
ARTICLE VII.
OFF-STREET PARKING.
Sec. 33-122 Required; definitions of parking space.
Permanently maintained off-street parking for vehicles
shall be provided in connection with any building or
premises used or designed to be used for the purposes
set forth in this article. For the purpose of this article,
each automobile parking space shall be a minimum of 9 by
19 feet with the following exceptions:
(1) where compact car spaces are
permitted, they shall be a minimum
of 7 1/2 by 15 feet.; and
(2) where parking spaces for the handi-
capped are to be provided, they shall be
a minimum of 13 by 19 feet or 21 feet by 19
feet for 2 contiguous spaces.
Parking stall and aisle dimensions shall conform to the
chart entitled' .. Minimum Parking Stall Dimensions"
hereby incorporated as part of this ordinance.
..
The percentage of compact spaces in any individual parkin~
_facility shall not excee~ 35% for facilities of 25 to 50
spaces; 40% for facilities of 51 to 250 spaces; and 45X
for facilities of 251 or more spaces.
-
~n rJ fc102D
n."". ..~........
WI"
Substitute
;,gendil 1 tcm No.
Page No. ~
2' (il)
l
;
J
I
1
I
,
I
1
,
1
I
I
I
.
1
,
I
1
j
1
The number of compact spaces permitted for surplus parking
shall be computed in accordance with the percentages set forth
above. The compact car spaces shall be clearly aes~gnat~ -
for "compact cars only". Handicapped spaces shall be
clearly designated for "handicapped only". All parking
spaces shall be marked with two distinct parallel lines to
identify and facilitate their use. The placement of compact
car spaces within a parking area shall be subject to s~te
plan review which shall take into consideration parking design
standards and such matters as frequency of use, safe and expe-
dient traffic flow, recognition and accoQmodation. For
purposes of this section, a compact car shall mean an automobile
which has a width of 70 inches or less and a length of 1HU inches
or less. In all instances, adequate interior driveways and
ingress and egress driveways shall be provided to connect all
parking spaces with a public street or alley. Where 4 parking
space heads into and abuts a sidewalk, the paved 19 or 15 foot
length shall he curbed at 17 feet or 13 feet for standard car
or compact car spaces respectively in order to prevent extension
of the vehicle over the sidewalk. Required and surplus parking
shall comply with these provisions and such parking shall not
be placed in dedicated or official rights-of-way. Private, non-
commercial off-street parking shall be reserved exclusively for
the tenant or owner and his customer and employees, unless
approved after a public hearing.
,
Modification of existing off-street parking areas to incorporate
compact spaces will be permitted providing the request complies with
all requirements of this ordinance, and a site plan is submittea
for review and is approved by the Building and Zoning and Planning
Departments.
Section 2. It is the intention of the Board of County
Commissioners, and it is herebyotdained that the provisions of
this ordinance shall become and be made a part of the Code of
Metropolitan Dade County, Florida; and that the sections of this
ordinance may be renumbered or relettered to accomplish such
J
I
j
1
intention, and the word "ordinance" may be changed to "section",
"article", or other appropriate wqrd.
Section 3.
If any s~ction, subsection, sentence, clause
or provision of this ordinance is held invalid, the remainder of
this ordinance shall not be affected thereby..
.Section 4.
The provisions of this ordinance shall become
effective ten (10) days after the date of its enactment.
PASSED AND ADOPTED:
October 2l, 1980
\
,
\
'Approved
form and
by County Attorney as to
legal sufficiency tAr:
Prepared by:
~'tJ7
9 PG1030
I
\' -'~~);" - .
:....,.~J_~. _, "
l ':~~';' r. . . ".
I .,~;.,?X .,- ..
j l:t;~~.,;.,_.~ :-~,. ," ~"""
.. .;~~~,. ":o>~.~...t',~~ :....'
BOCK
,-
. .
<-
.,
j
--
80 -: iiD
..
.
~
-, ,.-+
-;:';11I8_ I
I!
...- ..,aL:'
/^" /'
/ ,/,
'"
, ,
I,
-
"
I
'I'
"-
I
T
~
-1
[
t:.:
"
~-. ,,~,j
',I
~ I I
E::
,.-
i
I
0-;--<,
,
~c
I
G
, ,
XI !TJw.. '--!'IT .1.GCt~la~! IN CrRTJ.IH 1...l.Tcun
. MINIMUM PARKING STALL DIMENSIONS (IN FEET)
AT VARIOUS ANGLES' (a)
....
STANDARD (9' x 19' ) CO~IPACT (7.5' x IS' )
L':
450 600 750 900 450 600 750 900
12.7 10.4 9.3 9.0 10.6 8.7 7.6 7.5
28.0 24.2 21.4 19.0 22.5 19.3 17.0 15.0
19.8 21.0 20,7 19.0 15.9 16.7 16.4 15.0
12.0. 17.0 21.0 24.0 11. 0 14.0 17.4 20.0 [
16.6 18.7 19.5 19.0 13.3 14.9 15.5 15.0
48.4 56.7 61.2 62.0 40.2 45.6 49.3 50.0
45.2 55.4 61.0 62.0 37.6 43.8 48.4 50.0
46.4 55.4 59.7 59.5 38.7 43.8 47.3 48.0
2.0 2.3 2.5 2.5 1.5 1.8 2.0 2.c ~...
6.4 2.6 0.6 0.0 5.3 2.2 0.5 O. \' ~,.
13.4 9.5 4.9 0.0 10.6 7.5 3.9 0, C :::;:
14.0 14.0 14.0 14.0 13.0 13.0 13.0 13. ( ~"
22.0 22.0 22.0 22.0 20.0 20.0 20.0 20. C ;:'..
Dimension Symbol
Stall width, parallel to aisle A
Stall length of line B
Stall depth to wall C
Aisle width bet~leen stall lines D
Stall depth, interlock E
Module, wall to interlock F
~lodule, interlocking G
Module, interlock to curb face H
Bumper Overhang (typical) I
Offset J
Setback K
Cross Ai s leOne Way L
Cross Aisle Two Way
lFor parallel parking (a=Oo), "curbside," minimum widths and lengths are 8.0' x 23.0' for
standard stalls and 8.0' x 19.0' for ~ompacts. Practice not recommended.
t~~::
r-.
r-"
fu
t..,
L:-.:
\
* STRIPING DETAIL
BOC~ 9 rcl031
..
...
-
...
...
...
-
..
..
-
..
-
-
..
REVIEW OF
PARKING REQUIREMENTS
OF
REGIONAL MALL eEVELOPMENT
AND COMPARISON WITH
THE CITY OF BOYNTON BEACH ORDINANCE
PREPARED FOR
EDWARD J. DEBARTOLO CORPORATION
BY
GREINER ENVIRONMENTAL
GREINER ENGINEERING SCIENCES, INC.
711.5522
Gre
OCTOBER 1981
(J~
~.
REVIEW OF
PARKING REQUIREMENTS
OF
REGIONAL MALL DEVELOPMENT
AND COMPARISON WITH
THE CITY OF BOYNTON BEACH ORDINANCE
PREPARED FOR
EDWARD J. DEBARTOLO CORPORATION
BY
GREINER ENVIRONMENTAL
GREINER ENGINEERING SCIENCES, INC.
OCTOBER 1981
~ ~
INTRODUCTION
The criteria governing the provision of off-street parking
facilities is traditionally controlled at the local level. City
or County codes, zoning ordinances, and subdivision regulations
normally provide guidance to developers regarding both the number
and size of parking spaces required for a given facility. As may
be expected, these requirements vary somewhat among municipalities.
Experience has shown that there is a wide variation in the number of
spaces required while the variation in the size of spaces is more
limited. The explanation for this is that average vehicle size has
not changed appreciably until recently. The number of spaces required,
however, fluctuates widely depending on use and local interpretation
of parking needs.
Because of these variations, major national developers such as
the Edward J. DeBartolo Corporation have developed parking guide-
lines for use in their regional mall projects in order to provide
a measure of planning uniformity and land use efficiency. These
guidelines are based on the considerable research on the subject
of parking which has been undertaken by organizations such as the
Urban Land Institute, Institute of Traffic Engineers, and the High-
way Research Board. In addition, the research conducted by major
retail outlet and department store chains has also been considered
since these groups represent the major tenants who would participate
in developments such as the proposed Boynton Beach Mall.
In order for the City of Boynton Beach to evaluate these guide-
lines, they have been conpared to both the City's requirements as
set forth in Appendix A, Section 11-H of the City of Boynton Beach
1
Zoning Code and criteria provided by the national sources stated
above. City of Boynton Beach parking criteria are given in
Appendix A to this report.
2
SECTION I: PARKING RATIO REQUIREMENTS
Shopping centers, being a major generator of traffic, have
a need to handle a large parking demand during typical peak periods.
usually this requirement is based on a peak shopping period and
is expressed as a number of parking spaces per shopping area
(typically gross leasable area or GLA). Historically, the figure
for the average shopping center has been 5.5 parking spaces per
1
1,000 square feet of GLA. In recent years it has been found that
a ratio of 5.0 spaces per 1,000 square feet GLA will adequately
serve ~a11 ~but the highest one or two shopping days of the year
at most regional centers, 2 although recent studies have shown that
even lower ratios may be acceptable under controlled conditions,
where employee parking is restricted to off-site locations during
peak periods.
The City of Boynton Beach currently requires shopping centers
to provide one (1) space for each 150 square feet of retail floor
3
area. Table 1 compares this requirement with the criteria pro-
vided by the DeBartolo Corporation and other recognized sources in
order to illustrate the difference in total space requirements these
various criteria would produce.
For comparison purposes, the proposed project size is stated
l"GLA is all that area on which the tenants pay rent; it is
the area producing income." Community Builders Handbook, Urban Land
Institute, 1968.
2"The Dimensions of Parking", Urban Land Institute and National
Parking Association, 1979. (See Appendix B)
3 .
C~ty of Boynton Beach Zoning Code, Appendix A, Section 11,
Paragraph H4r.
3
0
r.l
t>:
H
"'0
ZO 0 t"'- t"'-
H[ii ..... N N '\
:><:t>: CO ..... ..... '"
t>: J'
.0:00 Lf1 Lf1 Lf1 I
p.,r.l V'!
()
.0:
p.,
00
-
Eo< (lj
Eo<r.. M aI aI
() Lf1 M M
r.l . .... N N
,..,0
aoo ..... Lf1 Lf1
t>:- t"'- N N
p., co 0 0
r.l .
N ..... ..... .0:
H ..:i
00 '"
z
a .....
00 0
H .0: .0: .0:
t>: r.. ..:i ..:i ""
.0: t>: '" '" Lf1
p., co
::!:
a +> +> +> (!)
..... () ..... ..... ..... ..0
.0: .
r.l a H 0' 0' 0' 0
..:i H t>: OJ OJ OJ +>
o:l ~ [ii
.0: Eo< 0 0 0 '"
Eo< t>: H Lf1 0 0 (!)
t>: ..... N N [3
'" () ..... ..... .....
z (!) (!) (!) OJ
H tJ tJ tJ OJ
:><: (lj (lj (lj (lj
t>: 0.. 0.. 0..
.0: OJ OJ OJ OJ
p., ..-i
..... ..... .....
..0 2
r..
aI t>:
t"'-
o.. aI
.. ..... <U
0 (!)
.c () ..
tJ (!) (lj ()
(lj 0 +> 4'
(!) ..... ::l .. X
o:l 0 +> 0 ..-i
+> ..-i 0 '"
c .. +> ..... c
0 (lj OJ ..... (!)
r.l +> o:l c ~ 0..
() C (!) H ..... ~
t>: >. 0 ~ ..-i
0 0 '" \\,) (lj
a i!l c +> (!)
00 ,.., (lj (!) (!)
..... ..:i t>: 00
0 '" ~ (lj ..0
.. C
>. <U <U
+> :J: ..0
..-i '" ..
() r.l 0
/
~
~
4
in both retail floor area (RFA) and gross leasable area or GLA as
previsouly defined.
In addition, RFA has been assumed to represent
85 percent of available GLA.
As Table 1 illustrates, the existing City of Boynton Beach
regulations could require a substantially higher number of spaces
than would normally be provided for a major regaional center. For
the Boynton Beach Mall project these requirements would translate
to a ratio. of approximately 5.6 spaces per 1,000 square feet of
gross leasable area.
A recent national study (see Appendix C) was completed to
determine if 5.5 parking spaces per 1,000 square feet of GLA was a
proper requirement for large scale regional mall development.
Major conclusions of this study included the following:
a. Older studies relating to the need for a 5.5 parking ratio
were based on shopping centers smaller in number and size.
The smaller retail facilities, by their nature of opera-
tion, require greater parking per unit space (5.5 ratiop
than larger facilities.
b. Recent data (1973-1975) on peak sales/traffic days at large
regional centers show a parking ratio of 5.0 as being
adequate to handle peak shopper demands.
c. The data also shows that the average peak parking demand
characteristics of eastern centers is less by as much as
one parking space per thousand feet of GLA over midwestern
and western centers, In addition, the average demand never
exceeded a 4.5 ratio on any given peak day in a study of
regional shopping centers in the greater Los Angeles area.
d. The recemmended ratio~ of 5.0 uses GLA as a base. As
stated in "The Community Builders Handbook" of the Urban
Land Institute, "GLA is all that area on which the tenants
pay rent; it is the area producing income." Therefore,
this would be the area related directly to off-street
parking requirements and should not include an area used in
common which is non-leasable.
The study concluded that for large regional malls, a parking
ratio of 5.0 parking spaces per 1,000 square feet of GLA would meet
5
the parking needs of mall patrons. This information has been
1
subsequently presented in the ITE Journal , September 1978.
While the Transportation and Traffic Engineering Handbook of
the Institute of Traffic Engineers suggests a design standard of
5.5 parking spaces per 1,000 square feet of GLA for the average
shopping center, it notes that the practice of some centers today
is to include some uses other than retail, such as theatres and
offices. The peaks for the other uses would not be the same as for
retail shopping. Therefore, it has been found that up to 20 percent
of the GLA can be added to a shopping center as office space without
affecting th~ peak parking demand.
Using the documented ratio for regional malls referenced above
(5.0 spaces/1,OOO square feet GLA) , it is proposed that 5,127 spaces
be provided to meet the parking requirement of mall patrons under
ultimate site development.
1The Official Tecnhical Publication of the Institute of
Transportation Engineers.
6
SECTION II: PARKING MODULE SIZE
In the design of an off-street parking facility, the ease
of entering, circulating, parking, and exiting the facility are
important factors. Related to ease of circulation and parking are
the parking dimensions and layout, or specifically, the parking
module1 size. The size of the module is totally dependent on the
size of the vehicle using the space. There should be adequate room
for the entering and aligning of the vehicle into a stall, the
opening of doors and exiting of passengers from the vehicle and the
unparking maneuvers from the space.
From the late 1940s through the mid-'70s American automobile
design followed a trend toward longer and wider vehicles. The
dimensions of parking stall sizes and aisle widths have necessarily
increased to keep pace with increased auto size. Recently, however,
automobile manufacturers have started "downsizing" or reducing the
overall size and weight of autos, in particular the larger standard
and luxury automobiles.
In addition, more and more drivers are
turning to smaller sized vehicles in the sub-compact and compact
size ranges. The result has been an appearance of predominantly
smaller vehicles. With economic and energy factors expected to be
similar in the near future, the trend toward the smaller car is
expected to continue. Likewise, the parking module dimensions can
be expected to decrease.
1A module consists of the width of the aisle, plus the
depth of the parking stalls on each side of the aisle.
7
The reasons for this trend toward smaller cars are based on
economics and energy considerations.
American automobile manufacturers and the public were hard
hit by dramatic fuel price increases throughout the 1970s. The
federal government, in attempting to lessen U.S. dependence on
imported oil, established overall average fleet fuel economy guide-
lines for automobile manufacturers. These guidelines required that
the miles-per-gallon rating for the average of all cars produced by
each manufacturer meet certain thresholds. These thresholds become
more stringent every year. Essentially, the government program means
that if a manufacturer wants to continue to produce large non-fuel-
efficient autos, he must also produce enough small, fuel-efficient
ones so that the average miles-per-ga1lon of all the autos he pro-
duces in a given year meets or exceeds a pre-set standard for that year.
In addition to the down-sizing attributable to the government's
program, the increase in fuel prices caused many automobile owners
to replace their cars with others which were more economical to
operate. It was at this time, mid-to-late 1970s, that foreign
manufacturers made tremendous inroads into the American automobile
market. The public was looking for small, fuel-efficient vehicles,
and foreign manufacturers had them available.
In efforts to comply with federal fuel efficiency guidelines
and to compete with imports, U.S. Automobile manufacturers de-
creased the size of their products significantly. The most dramatic
year-to-year size difference occurred for large-sized cars between
the 1976 and 1977 model years. Table 2 shows these reductions for
large American cars. The table also shows 1981 dimensions, which
indicate a continued trend in downsizing these vehicles. While the
8
b'I
c(!)-
..-i ..... +> M M N "" "" .0: .... .... N M "" N
C tJ (!) .....
.... (!) .... .... .... .... .... :z .... .... .... .... .... ....
::l..-i.....
()-
Eo<
~I OJ
,C (!) .0:
+>,C "" t"'- Lf1 co co ..... co co "" "" co ""
"'tJ t"'- t"'- t"'- t"'- t"'- t"'- t"'- t"'- t"'- t"'- t"'-
..-i C :z
~::!.
,COJ .0:
+> (!) ..... co N 0 N aI N CO ..... 0 ....
b'I,C N ..... ..... N N ..... 0 ..... ..... N N .....
C tJ N N N N N :z N N N N N N
(!) C
..:i..-i
b'I
c(!)-
..-f '"""" +J M M M CO CO aI CO CO M M aI M
C tJ (!)
.. (!) .... .... .... .... .... .... .... .... .... .... .... ....
.. ..-i..... .....
::l()_ CO
Eo< aI
.....
:z ~I
a OJ
H ,C (!) t"'-
Eo< +>,C t"'- t"'- "" 0 0 0 0 0 t"'- t"'- o "" t"'-
() '" tJ t"'- t"'- t"'- co co co co co t"'- t"'- co t"'- al
0 ..-i C .....
0 ~::!.
[ii
t>: ""
t"'-
t>: ,COJ aI
.0: +> (!) N co N t"'- ..... "" .... aI co 0 N .... .....
() b'I,C N ..... ..... N M N N N ..... N N .....
N C tJ N N N N N N N N N N N N .--l
r.l (!) C ..-i
[ii N ..:i..-i ..
..:i H 0..
o:l 00 -<
.0: b'I
Eo< r.l c(!)-
'-' ..-i,.....-l4-l (!)
t>: C tJ (!) t"'- Lf1 t"'- co co t"'- co t"'- Lf1 "" aI t"'- ::l
.0: .. (!) .... .... .... .... .... .... .... .... .... .... .... .... OJ
..:i \r...I..-j l.4-l OJ
::l()_ H
:z Eo<
.0: 0
() OJ +>
H ~I ,C (!) ::l
t>: +>,C 0 0 0 0 aI 0 0 0 0 0 0 0 .0:
[ii '" tJ co co co co t"'- co co co co co co co
~ ..-i C .--l
~::!. <U
::l
c
,C OJ ~
+> (!) M t"'- M t"'- ..... "" .... aI t"'- N N ""
b'I,C M N N N M N N N N M N N
C tJ N N N N N N N N N N N N OJ
(!) C +>
..:i..-i ..
0
(!)
.. co (!) t>:
(!) co >. .--l
...: .. ..0 ..
(lj +> .. (lj ::l (lj (lj (!)
.--l .. 0 OJ +> r.. c .--l e:
(lj 0 ~ ..-i .--l ..-i ..-i ::l
<U (!) 0.. 0.. ::l (!) co C .--l (lj OJ
.. .. e: :J: :J: 0 0' 0 aI (lj (lj :> c
+> ..0 H (!) (!) tJ .. .. +> (lj 0
(!) tJ (lj :z :z (lj <U (!) (!) '-' <U ()
.--l (!) 00 +> c ::!: .--l .--l () +>
..-i .--l (!) (!) .. .. 0 0 ..-i ..-i ,C 0
..0 [ii ..:i .--l (!) (!) ::!: Eo< >. ..0 ..0 +> tJ :z
0 0 .--l .--l ..:i .. 0 0 ::l <U [ii
e: ...: ...: .. OJ OJ (!) ::l e: E 0 ..-i ()
0 tJ tJ :> >. >. b'I '" tJ OJ OJ E +> t>:
+> ..-i ..-i (!) .. .. '" .. .. '" '" >. c .0: 0
~ ::l ::l ,C ,C ,C 0 0 (!) .--l .--l .--l 0 ..... a
o:l o:l () () () 0 r.. ::!: a a p., p., :z 00
9
average size reduction for these vehicles has not changed signi-
ficantly from 1977 to 1981, it can be seen that all models which
were not downsized between 1976 and 1977, were downsized by 1981.
Based on the data provided in Table 2, which was compiled from
Consumer Reports information, between 1976 and 1981 the automobile
industry made significant reductions in the size of large cars. All
but two of the models reduced their length by from 9 to 17 inches.
Fifty percent reduced their width by at least three inches. The
average reductions were 10 inches in length and 3 inches in width
for large cars.
The turning circle for these cars has dropped by from two to
five feet, with an average reduction of approximately three feet-
four inches.
Table 3 shows comparative sizes of other common automobiles for
1977 and 1981. Table 4 shows the general size classifications for
1973, 1981, and 1983.
This data indicated that today's large-sized cars now fit into
the traditional category lJfinteFmediate or medium-sized cars. The
overall U.S. fleet mix consists of significant numbers of these
smaller sized cars and this trend is likely to continue. Table 5
shows automobile registrations by size for 1973 and projections
through 1990.
This is not to say that there are no longer any of the tradi-
tionally-thought-of large autos in the U.S. fleet. These large older
vehicles should remain in the fleet into the 1990s.1
lITE Journal, "Parking Design for Downsized Cars." by Richard
1. Strickland, November 1980, p. 17 and Ibid, "Now is Not the Time
to Reduce Parking Dimensions," by James M. Hunnicutt, November 1980,
p. 20.
10
TABLE 3
TYPICAL AMERICAN AUTOMOBILE DIMENSIONS
LENGTH WIDTH TURNING CIRCLE
AUTOMOBILE (INCHES) (INCHES) (FEET)
1977 1981 1977 1981 1977 1981
Luxury
Eldorado 224 204 80 71 47 43
Continental 233 219 80 78 50 44
Large
Impala 212 212 76 75 43 42
LTD 224 209 80 78 48 44
New Yorker 231 222 80 78 48 46
Olds 98 220 221 77 76 43 43
Midsized
Matador 216 N/A 77 N/A 46 N/A
Chevel1e 210 N/A 77 N/A 42 N/A
Cutlass 215 199 77 72 44 41
Compact
Hornet 186 N/A 71 N/A 41 N/A
Nova 197 N/A 72 N/A 42 N/A
Granada 198 196 74 71 42 44
Omega 200 182 73 70 42 43
Vo1are 201 N/A 73 N/A 47 N/A
Sub-Compact
Chevette 159 165 62 62 34 35
Mustang 175 179 70 69 39 42
Sunbird 178 N/A 65 N/A 41 N/A
N/A - Not available
SOURCE: Consumer Reports, Annual Auto Issue, April 1977 and 1981.
11
TABLE 4
COMPARISON OF VEHICLE SIZE
1973-1983
(in inches)
LENGTH WIDTH
Vehicle Size 1973a 1981b 1983a 1973a 1981b 1983a
Low Avg. High Low Avg. High
Jtj 2d'{' I ".~ lfi.~ t1 C. ~ 7-:''\ 7~~ ~f (2-
Standard 228 217.7 222 204 9 75 74
'" ' I;;' e 11,'0 ,S b ~," 5''\ b'j. 6"9
Compact 198 176 189.5 213 180 72 65 70.7 74
\\,~ IYi,1 \";0 ,\ (,it 6 5 ,~ \::. ":..,..
Sub-Compact 168 142 169 198 162 69 60 64.9 74 65
l'i .{1 ~ 21r;,~
aAdapted from Richard I. Strickland, "parking Design for
Downsized Cars," ITE Journal, November 1980, p. 16.
b
Based on information in Consumer Reports, Annual Auto Issue,
April 1981 for "large, medium, and small" cars.
12
TABLE 5
AUTOMOBILE REGISTRATIONS, BY SIZE
(millions)
Year Regular % compact % Subcompact % Total %
Act. 1973 65.5 64.5 23.0 22.6 13.1 12.9 101.6 100
Est. 1975 63.5 59.8 24.6 23.2 18.1 17.0 106.2 100
1980 57.1 cff}) 30.9 26.3 29.5 25.1 117.5 100
1985 36.8 28 9 40.2 31. 5 50.4 39.6 127.4 100
1990 21.8 16 0 40.7 29.9 73.8 54.1 136.3 100
I
SOURCE: FHWA Highway Sta~istics Division Report, Projections of
Motor-Vehicle Re istrations, Driver Liscenses, and Motor-
Fuel Consum tion to 1990, L. L. Liston.
/
/V / ~ I;:
~ k~'~~l~~
-J ~ .~~~X__.
, ~ / 7.d-~."?r-',,c... p"/ .- '7
13
One factor which could influence how many of these large older
vehicles remain in the fleet is the price of gasoline.
Cambridge Systems, Inc. recently completed a study for the U.S.
Department of Transportation, The study projected the percentage
of future new car sales by vehicle size through 1985. The study
examined a low gas price scenario and a high gas price scenario.
The results of the study, shown on Table 6, indicate that regardless
of the price of gasoline the percentage of small vehicles in the
fleet would increase over the forecast period.
~nterestingly, the
results show that the percentage of new small domestic and imports
would be greater under the low gas price scenario. The report ex-
plains this b~ stating the assumption that under the high price
scenario people who operated large older fuel-inefficient vehicles
would be more likely to trade them in for the larger class of available
vehicles.
In the forecast years, the large vehicles would corres-
pond to ou'!: past anu present "mid-size" car class.
t
In light of the above trends in downsized automobiles, it
would be expected that the size of the spaces required to park these
vehicles would also become smaller.
In 1971, prior to the Arab Oil Embargo which initiated the
energy crisis, the Highway Research Board published Special Report
125, Parking Principles. This report stated that the optimum module
size for 900 (or straight in) parking consisted of two parking spaces
icJ
of 9'-0" X 18'-5" and a 26-foot aisle. This gave an overall module
length of 63 feet. Appendix D provides data pertaining to design from
Special Report 125.
The criteria set forth in the report have been accepted by such
origanizations as the Institute of Traffic Engineers (ITE). Their
14
TABLE 6
HISTORICAL AND SIMULATED TRENDS IN
COMPONENTS OF NEW CAR SALES
(Proportions under low/high gas price scenarios)
AUTOMOBILE CLASS
Small Domestic Mid-Size Full-Size
Year Plus Import Domestic Domestic
1971 .38 .21 .41
1973 .44 .23 .33
1976 .49 .38 .23
,
1979 .43/.43 .44/.44 .13/.13
1980 .41/.41 .41/.41 .19/.19
1981 .45/.45 .35/.35 .20/.19
1982 .47/.46 .38/.38 .14/.16
1983 .67/.53 .28/.38 .05/.09
1984 .58/.48 .33/.42 .09/.10
1985 .69/.53 .22/.40 .09/.07
SOURCE: Consumer Behavior Towards Fuel Efficient VehiCles, Volume II:
"Forecasts of the Composition of Household Motor Vehicle Holdings,"
by Leonard Sherman, Charles F. Manski, and J. Royce Ginn, of Cambridge
Systematics, Inc., prepared for U.S. Department of Transportation,
February 1980, p. 6-17.
15
Transportation and Traffic Engineering Handbook cites Parking
Principles liberally in the "Parking, Loading, and Terminal
Facilities" section of the handbook. 1 The handbook states that
"for higher turnover self-parking, a stall width of 9.0 feet is
recommended." In addition, "the stall length should be sufficient
to accommodate the length of almost all cars expecting to use the
space. "
The ITE also publishes a monthly magazine, the ITE Journal.
In November 1980 two articles appeared in which the authors dis-
cussed the impacts of downsized cars on parking design. Both
articles are included as Appendix E to this report.
The ~uthor of the first article advocates setting aside special
areas for smaller vehicles as well as a general reduction in parking
module size as vehicles are continually downsized. He quotes the
pr~j:_standard for 900 parking as having an~ ?",j-Joot stall width
and 60-foot overall module length. Each stall is thus 19 feet long
and the aisle is 22 feet wide. This yields 225 square feet per
vehicle, or a 20 percent decrease in the space per vehicle under
ITE standards for 900 parking.2
The author also notes that "pre-downsized cars should be
accommodated for 12 to 15 years into the mid-1990s."
In the second article the author discusses the problems associ-
ated with setting aside areas for smaller cars and concludes that
this is impractical. He also mentions that it would be "ten to
1Transportation and Traffic Engineering HandboOk, Institute
of Traffic Engineers, John E. Baerwald, ed, Prentice-Hall, Inc.
Englewood Cliffs, New Jersey, 1976, pp. 681-684.
2ITE Journal, "Parking Design for Downsized Cars", by Richard
I. Strickland, November 1980, p.16.
16
fifteen years at this rate before the fleet mix will permit a
smaller designed parking area..."
It is not the intent of this report to advocate a reduction
of the parking module size at Boynton Beach Mall below present
ITE standards. Rather, the purpose is to support use of the ITE
parking dimensional standards at the mall. Again, it must be
stressed that these design criteria pre-dated the current trend
toward downsizing of automobiles.
Table 7 compares the proposed parking stall dimensions to
those required under the present City of Boynton Beach ordinance
and those published by ITE.
TABLE 7
PARKING STALL DIMENSIONS
Proposed ITE Typical City of Boynton Bead
Parking Plan Parking Dimensions Ordinance
Stall Width (ft.) 9.0 9.0 10.0
Stall Depth (ft. ) 18.0 18.5 20.0
Aisle Width (ft. ) 27.0 26.0 25.0
Module Length (ft. ) 63.0 63.0 65.0
The proposed dimensions and those presently required by the
City of Boynton Beach are shown on Exhibits 1 and 2, respectively.
The only difference between the proposed dimensional standards
and those published by ITE for 900 parking is in the depth of the
stall and the width of the aisle. It should be noted that ITE
gives a range of from 8.5 feet to 9.5 feet for stall width. The
overall suggested depth of the module varies according to the width
of the stall. For an 8.5-foot stall, the module is 65 feet long,
17
~
~
D:
>-
'"
>-
z
~
~
>-
=
;a
~
I~I~:
I I I
I I ~
3 ~ I
I I
I I
3 3
-1~~
~
,..
~""
=~
~""
~
~..
~ -
~
of'.
~
~ ',po
"'--2
~
~
"
~ ~
,.. >-
~ >-
= ~
~ ,..
~
~ =
~ ~
~
~
,..
~""
=,..
~=
~ =
~
=
I
c,
=
-"'"
'"
=
'"
'-'
~
'"
~
-<..>-'
'"
.0
~
~
.
~ !....
>-
~
~ ~
,.,., ~
= '"
~
t-
a;
J:
X
w
.J
c(
~
W
o
z
oQ
w~
IDO
Ow
o..ID
Oe>
l[Z
0.._
:i
l[
c(
0..
"0
CD
III
~
i
~
III
~
!
>C
~
III
~
;:
11
.
..
, ,
~ ~
r~T~l
I I I r
I
\ I I , 0
0
...
= = c:. =
, '0
...
.' ra:
...
III
...
>C
U
III
,,'
-{r-
=
'0 >-
.~
:'0
..
.
o
o
...
N
~
III
:l:
X
w
~
u
:z
c
:z
-
=
1:1::
=
C
=
-
1:1::
=
-'
&.A.
~
=
U
C
~
CD
:z
=
....
Z
>-
=
CD
.....
=
>-
....
-
U
.~;o ~;I~ v./.. ~
and for a 9.5-foot stall, the module is 62 feet long.
L The proposed parking module would consist of a stall width
feet.
This would result in an overall module length of 63
of 27
-,
feet and
\\"
"
of 9.0 feet, a stall depth of 18.0 feet and an aisle width
1
an overall relative efficiency factor of 283.5 square feet per
stall. These dimensions would be adequate to handle the majority.
1 ~
\;,, :Y
of automobiles most efficiently. DV
/ :.-\
When the proposed plan shown on Exhibit 1 is compared to the
requirements of the City of Boynton Beach ordinance, some differ-
ences are noted. The ordinance requires that the stall width be
10 feet, with a stall depth of 20 feet and an aisle width of 25 .
feet for two-way movement. This requirement was shown on Exhibit
2. The overall relative efficiency factor for these dimensions is
325 square feet per stall.
The dimensions used in the proposed plan (Exhibit 1) have
been developed as a result of several studies and research in
regional mall parking as referenced above. It is believed that
the proposed plan would adequately serve the patron parking needs
for the mall in Boynton Beach.
~,
Module size in the proposed plan is approximately 13 percent
smaller than the presently required module size. Based on the
accepted standards for the retail industry and parking requirements,
this additional amount of pavement is not necessary and could be
used for other site purposes.
1Relative efficiency factor is the number of square feet
per stall plus one-half of the aisle area for the stall.
18
When this sj~~E~~ction is coupled with the proposed decrease
in the number ot:_.t::~g\l~red"'p_arking spaces (discussed in Section I),
the combined result is a net ciecrE;!a~in the amount of pavement
of approximately twenty-five perce~ At a development of this
.....-..
size this amounts to nearly 10 acres less paved area.
The economic and environmental benefits of such a reduction
are significant. These benefits are enumerated below.
1.
to..
,; , ,
,.
( ,.
i
,. 2.
3.
One major benefit is a reduction in the amoun~o~r\lnoff
gene!:,ated by the site. This is in keeping with-;~"best
management practices" put forth by the U.S. Environmental
Protection Agency.
Cost savings could be applied to other project elements.
The excess space could be dedicated to a higher and better
use. Efficient use of space is more important today than
ever before. Even though portions of the 10 acres may
be used for other uses it is extremely likely that certain
areas would be left open or landscaped, thus enhancing
the aesthetics and environmental quality of the site.
I
( ,
1'"
"
I.,
( "
19
SECTION III: RECOMMENDATIONS
Based on the findings discussed in this report, the following
requirements are recommended for off-street parking and loading
spaces in Boynton Beach, Florida, for the proposed regional shopping
center development:
* The use of gross leasable area (GLA) in determining off-
street parking requirements.
* A parking ratio of 5.0 parking spaces per 1,000 square
feet of gross leasable area (GLA) should be utilized.
* Assuming 90-degree parking, a parking space requirement
of a 9-foot by 18-foot rectangle, with a 27-foot aisle
width for an overall module length of 63 feet.
20
CITY of
BOYNTON BEACH
~
P. O. BOX 310
120 N.E. 2ND AVENUE
BOYNTON BEACH, FLORIDA 3343!5
~=~~
August 20, 1981
~tr. Tom Marsicano
Greiner Engineering Sciences
P.O.Box 23646
Tampa, Florida 33623
00 [g@[gDWgW
AUG 24 1981
GREINER ENGINEERING SCIENCES INe.
TAMPA, FLORIDA '
Dear Mr. Marsicano:
consistent with our recent telephone
conversation, please find copies of the pertinent
pages of the Boynton Beach Code pertaining to off-
street parking and a parking stall dimension diagram.
These documents are submitted to you in connection
with your study of the proposed DeBartelo Mall parking
plan.
Please advise if you require any additional
information.
Yours very truly,
CITY OF BOYNTON BEACH
C ~~ 5'c~-:Y-'-ct,
Carmen S. Annunziato
City Planner
CSA:mpc
cc: City Manager
Central File
A-I
APPENDIX A-ZONING
See. 11
with the city swimming pool ordinance and shall be subject
to the approval of the building department. No swimming
pool shall be constructed closer than eight (8) feet from any
property line and no swimming pool shall be built in front
of the building line. On corner lots, property bordering both
streets shall be considered as front yards. Location of above
ground pools shall comply with building set-back require-
ments.
F. SCREEN ENCLOSURES. All screen enclosures (screen
walls and screen roof) shall comply with building side yard
setback. No screen enclosure shall be constructed closer
than eigM (8) feet from rear property line and no screen
enclosure shall be constructed in front of the building line.
On corner lots, property bordering both streets shall be
considered as front yards.
G. TOWN HOUSE. All town house developments shall
conform to the district zoning and shall meet the following
minimum requirements:
1. Each town house shall have its own lot area, each yard
private and reasonably secluded from view of streets
or neighboring property.
2. Each town house shall have a direct automotive ac-
cess from the off-street parking space to a public street.
3. All outdoor, rear yard areas used for drying of clothes
shall be screened from view from the street and from
adjoining yards and lots.
4. Parking space shall be provided for as by section
ll-H.
H. OFF-STREET PARKING.
1. For the purpose of this ordinance, the term "off-street
parking space" shall mean a parking space construct-
ed of a hard surface and shall consist of a minimum
net area of two hundred (200) square feet of
appropriate dimensions, and not less than ten (10) feet
in width. for parking an automobile, exclusive of
access drives or aisles thereto or any street or alley
right-of-way.
(
1945
A-2
See. 11
BOYNTON BEACH CODE
2. All required off-street parking facilities shall be
drained so as not to cause any nuisance to adjacent
private or public property.
3. A certificate of occupancy for the given structure or
premises shall not be issued until the required parking
area has been inspected and approved.
4. There shall be provided, at the time of the erection of
any main building or structure, or at the time any
building or structure is enlarged or increased in
capacity by adding dwelling units, guests rooms, floor
area or s~ts; minimum off-street automobile parking
space with adequate provisions for ingress and egress
by an automobile of standard size, in accordance with
the following minimum requirements:
a. Single-family dwelling structures: Two (2) spaces
for each dwelling unit.
b. Multiple-family dwelling structures: Two (2) spaces
for each dwelling unit.
c. Churches, temples, or other places of worship:- One
space for each four seats in the main auditorium.
d. Commercial manufacturing, and industrial concern
no catering to the retail trade: One space for each
two (2) employees on the largest working shift, but
not less than one space for each four hundred
(400) square feet of floor area, exclusive of that
area used for storage, plus one space for each
company vehicle operating from the premises.
e. Country, golf, gun club: One space for each five (5)
members.
f. General business, commercial or personal service
establishments, not including meat markets,
grocery stores, or shopping centers: One space for
each two hundred (200) square feet of non-storage
floor area.
g. Hotels: One space for each bedroom, plus one
additional space for each two (2) employees.
h. Hospitals, sanitariums, convalescent, and nursing
homes: One space for each three (3) beds, one
1946
A-3
APPENDIX A-ZONING
Sec. 11
space for each two (2) staff doctors and one space
for each two (2) employees on the largest shift.
i. Kennels and animal hospitals: One parking space
for each three hundred (300) square feet of floor
area.
j. Libraries, museums: One parking space for each
three hundred (300) square feet of the floor area
open to the public.
k. Medical or dental offices or clinics: Six (6) spaces
for each doctor or dentist.
I. Motels: One space for each bedroom, plus one space
for resident manager, or owner, plus one space for
" each two (2) employees.
m. Office and public buildings: One space for each
three hundred (300) square feet of floor area
within the building.
n. Private club or lodge: One space for each four (4)
seats.
o. Restaurants. One space for each three (3) seats
plus one space for each two (2) employees.
p. Rooming, boarding houses, dormitories: One space
for each sleeping unit.
q. Private schools: One space for each employee plus
one space for each three (3) students of driving
age, plus one space for each one thousand (1,000)
square feet of floor area of fraction thereof.
r. Shopping centers, including meat markets and
grocery stores: One space for each one hundred
fifty (150) square feet of retail floor area.
s. Theatres, auditoriums, places of assembly: One
space for each four (4) seats.
t. Bowling alleys: Four (4) spaces for each bowling
lane.
u. Marinas: One space for each boat slip plus
required spaces for any eating, motel or commer-
cial facility on premises.
v. Mixed uses: In the case of mixed uses, the total
requirements for off-street parking shall be the
sum of the requirements of the various uses
computed separately. Off-street parking space for
(
~.
1947
~.
A-4
See. 11
BOYNTON BEACH CODE
one use shall not be considered as providing the
required off-street parking for any other use.
w. All other uses: Parking requirements for uses not
listed in this section shall be determined by the
city council after review and recommendation by
the planning and zoning board.
I. LOCATION OF OFF-STREET PARKING SPACES.
1. Parking spaces for all dwellings shall be located on the
same lot with the main building to be served.
2. Parking spaces for other uses shall be owned and
provided ?In the same lot or not more than three
hundred (300) feet distant, as measured along the
nearest pedestrian walkway.
3. Parking requirements of two (2) or more uses of the
same or different types may be satisfied by the
allocation of the required number of spaces of each use
in a common parking facility.
J. OFF-STREET LOADING:
1. For the purpose of this ordinance, the term "off-street
loading or unloading space" shall mean a vehicular
loading space constructed of a hard surface and shall
consist of a space with dimensions not less than
twelve (12) feet in width, thirty-five (35) feet in length
and fourteen (14) feet in height, exclusive of access
aisles, maneuvering space or alley right-of-way.
2. The following spaces shall be provided for the uses
indicated:
a. Every hospital, institution, hotel, commercial or
industrial building, or similar use, requiring the
receipt or distribution by vehicle of materials or
merchandise, shall have sufficient permanently
maintained off-street loading space so as not to
hinder the free movement of vehicles and
pedestrians over a street or sidewalk.
b. All structures requiring the pickup of large
quantities of garbage or trash shall provide an
1948
A-5
(
APPENDIX A-ZONING
See. 11
easily accessible area for the pickup and delivery
of a dumpster or other trash receptacle; all such
areas shall be so designed that garbage and trash
pickup can be accomplished without excessive
maneuvering such as turning around and backing
up.
K. PERMANENT RESERVATION OF SPACES. Area
reserved for off-street parking or loading, in accordance
with the requirements of this section, shall not be reduced in
area or changed to any other use unless equivalent
off-street parking or loading is provided in accordance with
this section.
....
, L. SERVICE STATIONS WITH OR WITHOUT MAJOR
REPAIRS.
1. There shall be a minimum distance of one thousand
(1,000) feet between the nearest property line of the lot
or plot of land upon which the proposed service
station is to be constructed, and the nearest property
line of a lot or plot of land upon which any other
gasoline service station, church, public playground,
hospital, public school or other similar public or
semipublic place where large numbers of people
congregate, is located. Such distance shall be by direct
airline measurement.
2. The minimum size plot of land shall be seventeen
thousand five hundred (17,500) feet in area with a
minimum frontage of one hundred seventy-five (175)
feet, on all abutting streets.
3. At least ten percent (10%) of the gross plot area shall
consist of landscaping equipped with adequate sprin-
kler systems of which at least five percent (5 %) shall
be adjacent to the public right-of.way. All land-
scaping shall be maintained in a healthy growing
condition.
4. There shall be a minimum distance of fifteen (15) feet
between the location of a gas pump island and any
adjacent property line.
(
1949
A-6
"
..----... --_.....- --...-----------------
.-..---.
~ ":
". . j. ~ .
, '
" :': .
- ,. .~
- ,~
0
~
-
'" '1 ..
0
~
~ -
- 0
0 3=
-
0' ~
c:: 0 .. ~
:;: lL.
~
0
0-
-",
, ,
\ \
!,
"
"
"
-(0
11
:.1
lJ
't'
I
(/)
c
0
en ~, ~.~ "~
c u 'it co ~ 3, '
,'or \n -1l.
Q.) c .i
F ;. _m .= ;;, \'t 0 U
-m or' ,<" -<0 c-.) . ;I, 0
I:: ...; l.:; ~, ~.. '" n
"., m
-0 '" -=
- 0 ~
'" "" ;; or = ,m -" 0
-<( "'~ l'~' '" w. .. 'iT n "-
0' u
e > '"
D <( 0 0 0 0 0 s:
0 0 .c
+- 0 0 to 0 ,0 --:".'
(/) en 0
0> r0 '<l" <D n H
e ' u -"
-'" ;., -'" '0 ~~ .;\~ U. '"
~ u '::~ ..~ "' E
01 0 I':;' <, 0 m
a.. ~ c
C u :;;
-- - I ~- <;
~ m ~ ", C> -lh ~- ..~' '" "-
w "". ~L..r
",: '. .
>- W
0 I-
0
0- <( - m -;n z
'". rl. .~:
~, ,'" ,., ",
....
,-.:
'.
.' ~ '.-.'
'., ~.
,n
" )
,.
-
-
0 .:
~
- .1 '.
"
>- :{
0
;<; ....:
'" ".1'
e "
0
~ .:;::
.
0 :
lL. "
,~ ..
." :. CD
I; I
,,' ..'
"
1
.;..
, A-7
\ t
..
" t> 1 " 'f
.f +.
I
I
1
"0
. '
..
....
'"
"
v,
C
~
~
o
"
.
~" ,~
,..
c5
...= Ie
O-la
'" '0
0_
ci
on
e
V'
j
,
<tJ
,
o
'"
0> _
e 0
W-O
~-
.
:~.~.
-
,
.a
-.
"'
f
en <r.
, I;;
'" Ii
'"
.,;
~
0
DC
-0'
>-
0
LL
-
..c:
()
D
Q.)
ro
c
0
cl
>,>'
0:
ro
'I-
0
>'
..-
10
, : .
..-
j~
, I
I
..,.
,.
i
;::"
,
(f)
C
o
.-
(f)
C
ill
E
u
o
+-
(f)
O'l
C
~
'-
o
II
,'::'
./ ~~.:
., .
"
. -."
','
.....
"
,....... :....
....;cP-"Il~;.
.~ ,; ...,_.
~~~
I . ~:I~~Y. . I
~[I" I
-
A-8
'.
'-;-;:...:;',
'.'r
,.",
"'>h:-
"."1"
...., ......_~
". '. l~
'.'
-,
',~
'"0
<D
o
o
Q)
....
'.:.:....,
:14
....
,,-
m
"
m
M
.1lf1=:i~l
;,.:....;.,
.'
~,
_4..-....
,
,
I
,- .
-..--
'.
"
'.
.
.....
';".:..
"
o
'0
o
o
r<J
o
l{)
<j-
",
ci
- c
a. ..0
'"
0 0
"
a. ,
U)
c
d:5 c
'"
0> -
C 0..
W -0
,
,
,
Ol
,
'"
"' .
'0
o
o
u
.....
o
lL
..c
()
o
ill
m
c
o
+-
c:
~
o
m
'<-
o
~
+-
<-)
From:
The Dimensions of Parking, by Urban Land Institute
and National Parking Association, 1979.
Demand
Jean M. Keneipp
The estimation of parking demand is a critical step in
the evolution of a development that will attract auto
driver trips, Unfortunately, parking demand estima-
tion is complex, misunderstood, and often ap-
proached incorrectly, Done properly, demand estima-
tion can be time-consuming and expensive, so there
can be the temptation to employ shortcuts which yield
results with high percentages of error.
A common shortcut involves the use of factors ob-
tained from a table or listing of questionable. inap-
propriate. unknown. or obsolete origin. Once a factor
is selected from such a source, however, there is the
tendency to forget its limitations. The resulting esti-
mates might not be questioned until the proposed de-
velopment is open for business and discovery is made
that actual parking generation is at variance with the
estimates,
No simple set of factors can be developed to accurately
support an estimate of parking demand, No system
could be accurately used to estimate parking demand
for a retail establishment that might be located in a
suburban area of California, a small community in the
Midwest, or in the heart of an older la"!le city in the
East. Even if a magic factor with a high degree of accu-
racy could be derived for current conditions. it would
become 'obsolete i~ a few years as inevitable changes
occur in transportation characteristics. policies. and
environmental constraints.
~~
One instance in which a parking factor changed is re-
ported in the May. 1977 issue of Urban Land (See Ap-
pendix B), The article, "Parking Demand at the Re-
gionals," deals with the parking factor used to deter-
mine space requirements for regional shopping cen-
ters with gross leasable areas in excess of 800,000
square feet. ln~Q2"..th~$h9Pping center i!ldustry
standard became 5.5.par,lgng spa.'es-p<<~l..Q.OO squ~e
feet of GLA due, 10 the.findings QJ il.1265 J.,lg st!l.gy,
Parking Requirements fOT Shopping Centers, Technical
Bulletin 53, On the basis of extensive research re-
ported in the more recent article however. "5,0 park-
ing spaces per 1.000 sq!,1~eJeel oJ.gJ;9~ssJeilsilQle..jjJ'ea
would be, ingen~r~l,~a valid.nati,QnaLll}ll~imu"La,,_a
basis for current plannin!'; for ne~~.onsting" MIs! ~ex-
panding regional shopping centers...whichhave,~ Dr
will have, a GLA gre~teLthll!l~1L09,9Q.O_ s_~'!aI'!'Jeet. In
~fact, a reduction to 4,0 spaces per 1,000 square feet of
GLA is recommended in cases where employee-
owned vehicles can be directed by prior agreement to
off-site parking facilities during peak shopping
periods, such as the, Thanksgiving-to-Christmas
period, pre-Easter, and other peak sales days,"
~ . , '10.~
The 1977 study concluded that various factors affect
the reduction in the parking ratio--a higher propor'
tion of multiple purpose trips since shopping centers
provide new services, fuel shortages and higher fuel
prices. changes in daily shopping patterns, and in-
creased use of public transit,
B-1
17
"
i
4-1 Since 1965 the provision of 5.5 car parking spaces per 1,000 square feet of gross leasable area has been
considered adequate as a standard. to meet the demand for parking space at shopping centers. There is some
question now as to whether this standard is still valid.
Rather than list a myriad of magic factors for estimat-
ing parking demand, the following discussion
suggests a rational approach to demand estimation. A
range of factors is provided to assist the planner in
developing estimates in selected, typical situations,
Through experience. most planners can amass a data
bank of parking generation factors for future use, F ac-
tors should only be used if their source, applicability.
and limitations are adequately understood,
Terminology
The term "'parking demand"' is equivalent to the term
"'parking generation,"' Both of these terms, however,
have an entirely different meaning from "'parking
need"' or the "required capacity" of a given parking
facility, B~sic ,parking de!".~.<! ()r,,g~!,eratio." repre-
sents the number of patrons that would beattracted to
a. given generator-a single l'.urp<:>se building, a
multi-purPose building. or a group of buildings that
attr"ct ,!ut()~()~l<:.<irivl!rs. i'Parklng~ need'" represents
the number of patronstl1at need to be accommodated
in a given parking facilitY after, ifi'e-use'ofaltemative
parking facilities is considered,
'0
Parking demand cannot be defined without introduc-
ing the concept of a time frame, Person-trips are nor-
mally estimated in terms of a 24-hour day; the result-
ing parking demand similarly reflects an entire day,
:>f However, the number 9f parking spaces required to
meet):>arking demands should reflect the peak hour
requirement during the day, Additionally, the park-
ing demand of many generators fluct,:,~tes in a
periodic or non-periodic pattern, Periodic cycles can
reflect day of the week, month of the year, or season of
the year, Thus, the time frame concept leads to peak,
or maximurn.aemand during the peak season, From a
fundamental viewpoint, the peak hour demand dur-
ing the peak season is part of the parking demand or
generation description for a given land use or space
use, The "design factor" concept does not apply to
basic parking generation or demand-design factor
only applies to an estimation of parking needs,
In some instances, a planner is concerned with es-
timating parking demand for a single specific
generator, However, the more usual task involves es-
timation of demand for a group of generators, such as
a multi-use building, center, or area, The 1?19p,erJ!p-
proach for determining parking requirements of mul-
, tiple generators is to estimate the parking demand for
each, Once this estimate is completed, the synergistic
effects must be evaluated,
B-2
Demand Parameters
There are three lundamental sets 01 parameters that
control the parking demand 01 a given land use, Some
aspects relate to the general area in which the de-
velopment is to be located-trade area characteristics;
other aspects relate specifically to the site on which it
will be situated-site characteristics,
. Basic Demand-The first set 01 parameters
provide the basis lor estimating the number of
person-trips attracted to the proposed develop-
ment, including:
-Land and/or building use (size, purpose, spe-
cial conditions)
-Socio-economic characteristics 01 the persons
expected to visit the development)
-Alternative modes (availability, attractiveness,
use. and policy impacts),
. Constrainin~ Factors--'-Assessment 01 the follow-
ing points pernnts the planner to determine the
manner in which the basic person-trip demand
would be diminished:
-Multiple use trips (proportion)
-Traffic accessibility to the site
-Parking facility efficiency and attracti veness
-Parking space availability
-Cost of parking " 1
-Local policy and codeS, \",
I
. Time Frame Factors-This step in the analysis
would translate daily auto driver trip demand
into appropriate formats needed to size parking
facility requirements:
-Peak to daily relationships
-Periodic factors (daily, monthly. seasonal)
-Non-periodic factors (long-term changes,
abrupt changes),
An indication of how the parameters would be used in
estimating demand is illustrated in Figure 4-2. This
illustration also indicates the difference between
"demand" and "needs," The proposed development.
the generator, is defined or quantified in the back-
ground phase, Its size-measured in terms of
employees, square footage. seats, or other param-
eters-must be established in order to estimate the
number of person-trips that would be attracted to it.
- Bock(l>OUnd - ~'~
-...,--=- ~~-.--....~':'"<'_..~..,..~.
'>' L3t:}J~~ .. :~-:-,~,,:"'.:'~-" ,'-:::'
... ',..:-.,.
..~.,. - ~~-..':';:',-".'
:~."~';.--'--:,,"
OeT...~F
.j:>"-.~-.::;'.~'
, .....'1""... ,Oh ~
. :";'""1~.-.:;:::~~~".:
Def.. trip maker.
. . 'cbarac:b:ristics
-
-....-,..".
r.' ,,~~...,-:-,
. Define trade area.
fransportation and
cond"8ining - .
ch8racteristics
c
--
...........-...,
Definr time- fnI.,.
,;
4-2 Parking Demand Estimation Process
B-3
19
From:
The Dimensions of Parking, by Urban Land Institute
and National Parking Association, 1979.
Appendix B
'Parking Demond at the Regionals"
Jlntil 1965. the amount of on.site shopping center parking nuded to
.ommodate retail customers and others had betn debatable. In that
.:aT. hOWt:.JCT, ULI published T.B. 53 which ucommended that "where
there is virt:.ally no wa!k-Irl trade nor public transit usage, the provision
of 5.3 car parking spaces per thousand square fut of gross leasable area
IlJ~q-I.HJte as d standard to mut the demand. . . . "Ruently, Barlon.
5chman Associates conducted a study of parking demand al centers in
excess of SOO.OOO square feet. T},~ indicate that the standard may 1'10
f(l'/'lger be i.'alia. The fol/owing is taken from tire May 1977, Urban Land.
I the Fast. available land for development was plentiful and rela.
tively inexpensive. energy was thought of as a virtually unlimited
reso~rce. the population was steadily increasing to open up new
Larkets and expand established ones. and the environment was
'(,lUsht of as trees, flowers, rustic fences, and the lik~more of an
amenity than anything else. Today the emphasis has changed dra~
maticaUy. All forms of development, including shopping centers,
'e entering a new era for which the ethic will be conservation.
_ n that basis, therefore. i~ is incumbent upon all of us, when for~
mulating new plans, to maximize the efficiency with which our
esent resources are utilized and where possible, replaced. For
.ample, local governments throughout the United States should
It'"examine their zoning ordinances and shopping center parking
requirements with an eye toward achieving the goals of conserving
nd, energy, and human resources. In order to be effective, how~
er, any recommendations that are advanced must be im.
pll~mented by conventional zoning and subdivision tools, and by
securing public recognition and support.
lis research study indicates one way in which the conservation
lic can be achieved within the shopping center industry. The
~'~rpose cf tne study was to investigate peak parking accumulations
~gional shoppir.,g centers in excess of 800,000 square fc:et of oc.
c':Jpied gross leasable area (GLA). These parking characteristics
were evaluated during pre~Christmas peaks in an attempt to update
the parking requirements for both new centers, and existing ones
for which upgrading, expansion, or modernization is con~
templated.
Background
Because of the sheer magnitude of regional centers, their proposals
have nearly always undergone some type of transportation impact
analysis: transportation impact is explored in terms of the potential
impact not only adjacent to the shopping center site, but also upon
the entire transportation system serving the community Or region.
Also, because of their size, regional shopping cente:s historically
have been subjected to the scrutiny of environmentalists, mu~
nicipal and state officials, and concerned neIghbors. The two trans~
portation aspects of regional shopping centers most often discussed
invuive automobile trip generation and parking concentration-
p~rhaps more precisely, the potential noise and airpoliution gener~
ated by heavy concentrations of automobile traffic.
For example, recent studies by Barton~Aschman and others for a
number of locations have shown that proposed commercial centers
can lead to a net reduction of average shopping trip length, when
placed within market areas presently under-served by retail
facilities, and hence can offer a net reduction in total vehicle miles of
travel (VMT) on a regional basis. In addition. in an effort to investj.
gate and reduce further the effects oi automobile trip generation,
many developers of new centers, and owners of centers about to be
upgraded Or modernized, are attempting to integrate public transit
facilities-bus stops and platforms or transit centers-within the
shopping center.
Aithough many centers-new .3nd E'l".lsang- are providing parkmb:
areas with better landscaring i'lnc ~etter cIrculatIOn ratte:-ns ~han In
the past, the fact remains th.lt very l~rge portions of the sites still
C-1
115
FIGURE 1
OAI L Y RETAIL SALES
I
~i
!
~~
I
'IT'''G,ot,,o..'"~''''''_.''.O.IC".'IN'''
i
, _ ~!.!'..!!.'~U'~~ :...'<!!.'.Q.' ~".1.~G!. _ _ _ _ _ _
'] - - - - - - - --'~'..~;;'''''....;;...,..i...i...-- - - - - - --
I
"
~
~
~ ~ c
.....0' c..
~
c
~
'00
must continue to be devoted to customer and employee parking.
For the past 12 years the shopping center industry has used a stan-
dard of 5.5 parking spaces per 1.000 square feet of GLA, which
means that a shopping center having 1.000,000 square feet of GLA
would require 5.500 parking spaces. Surface parking facilities of
this magnitude typically acc:upy between 50 and 60 acres. This
standard was based. on a 1965 UU study. Parking Requimnents for
Shopping Centers, Technical Bulletin 53. T.B. 53, which dealt with
centers ranging in size from ]0.000 square feet of GLA to over
1,000.000 square feet of GLA, covered 270 separate centers, only 12
of which had more than 800,000 square feet of GLA.
Since the literal adoption of this standard, a number of significant
changes have taken place in the evolution ofregionalshoppingcen-
tets. Many more regional centers have been built, some in the pre-
viously exclusive trade areas of existing centers. New land uses
within centers-banks, auto service centers, theaters. health dubs.
and other service uses-have been developed which exhibit either
low parking demands per unit of floor area, or peak parking periods
which do not conflict with the peak parking demands afretaij activ-
ity Moreover, daily shopping pattems have changed because of the
increased level of accessibility afforded by the automobile. For
example, the early afternoon trip made for a variety of purposes,
induding shopping, is now commonplace.
Even more changes are occurring daily that are likely to affect the
form, function, and diversification of regional shopping centers.
Fuel shortages and higher fuel prices may alter retail travel patterns,
and a decrease in per capita spending power may change the family
shopping habits. all factors which could increase activity at some
centers and decre3se it at others. Environmental Protection Agency
regulations could also dramatically affect shapp-lOg center planning
and operation; hence. the implications of such regulation must be
carefully considered.
Over a period encompassing nearly three decades-virtuaUy the
entire history of the shopping center as a definable, generic. built
entity-Barton.Aschman has observed changes in shoppmg-
center-generated travel pattems which indicate that shopping cen-
ler customers are learning to use shopping, access, circulation. and
parking facilities mOre efficiently. Barton-Aschman has been able
to study existlOg centers in sufficient detail to reliably predict the
volume of vehicle trips mace to and from proposed new centers on a
daily and hourly basis. 1n \.ie...... of the development of the shopping
center industry up to this point, and with an eye on conser.,;Jhon
116
FIGURE 2
OAIL Y TRAFFIC VOLUMES
..'0:'.....10..",..'0'0"....,......_"(.,,,,..C
'..0.........'0..0. ......O,.,.'u.DA.".O.,~.........
J.o_non"c(>OIc..Tu.on.l'04tle.....'.....
...........u.O.., ,.,.f\,l.on...T1.'.....,u,,~,v_
.......CO>oInO"........U.C.".H~.C>>Aln......
~
,~
,00J
J
I
......_..U10n.
1oI"<.000."I"'e,oa"
"
~
.
~ . .
.....~ Of c....,
~
~
.
'00
changes to come, it appeared appropriate for Barton-Aschman to
review the industry standard for determining the quantity of park-
ing to be provided at regional centers.
Procedure
Since the purpose of this parking study was to determine current
peak parking demand, it was first necessary to determine ........hen
peak parking demands occurred. Although recent parking accumu-
lation data indicated that peak parking demand at larger regional
centers was less than 5.5 vehicles per 1,000 square feet of gross leas-
able retail space, there was no indication that shoppers had
changed their seasonal or daily purchasing habits. In other words,
the pre-Christmas shopping days were still observed to be the
highest traffic activity days. and the highest parking accumulations
apparently were still occurring at some time between LOa p.m. and
4:00 p.m. on weekdays. Saturdays. and Sundays. where Sunday
opening is penmtted. In order to confirm these observations, three
kinds of data were further researched and analyzed: dailv retail
sales volumes for a l~year period; daily inboun.d shoppe; traffic
volumes at several regional shopping centers; and hourly and daily
peak parking accumulations at several reglonal shopping centers.
Figure 1 illustrates the results of daily retail sales surveys. The retail
sales curve was determined from daily sales data obtained from a
major department store in each of four reglonal shopping centers.
The inbound shopper traffic volume curve (Figure 2) was deter-
mined from daily inbound shopper traffjc volume counts taken
throughout a full year andor the months including Thanksgi\'ing
and Christmas at three regional shopping centers. The results indi-
cate that the Friday following Thanksgiving and the Saturdays be-
tween Thanksgiving and Christmas continue to represent the peak
shopping and traffic activity days at regional shopping centers.
As was the case during the early 19605. shoppers still tend to con.
centrate their shopping tnps on Fndays and the weekends (see Fig-
ure 3). even though many more regional centers are now open eve-
nings on several. if not all. weekdays. As sho\,.n ir: Figure .;, the
peak parking accumu].wons are still occurrins durmg the mid-
Jitemoon bet\....een 1:00 p,m. and .t:OO p.rn This cur....e was estab-
lished. from an analySiS at" ;,our:y pilrking accumul.Jtions surveyeJ
at two regior,al ~'norpins centers Ju:-ine: the dJYs between
ThJni-.sgi\.ing and Chri~!ma5, At one of the rt'swn,ll centers. houri\"
parklOS accumulatiol1s v.ere J\"ddJble for::(1 .::ontinuous dJ~.5 in-
C-2
FIGURE 3
OAll Y PEAK PARKING DEMANDS
..
..
..
"
"
'.
'UllOU ...""'uo.-~ ......so.o.. _.'On lo."u.l)ao S\;fIoOn _0'"
ll'" I) ':'.iIJ l1'~"J ,~,:"n 11111') 11'l:lJ71 "11"'1)
eluding the two Saturdays preceding Christmas, which allowed a
daily peak parking 3crumulation comparison.
As a result of the aforementioned research. it was determined that
peak parking demands would most likely occur from 1:00 p.m. to
4:00 p.m. on the days between Thanksgiving and Christmas, par~
ticularly on the Friday following Thanksgiving and on the Satur.
days between the two holidays. Based upon these findings:- it was
decided that additional peak parking accumulation data would be
secured by taktng aerial photographs of regional shopping centers
during this mid-afternoon time segment on the days between
Thanksgiving and Christmas. The decision to use aerial photogra.
phy was based primarily on the desired accuracy of the counts. Past
experience had revealed that counts by personnel surveying the lots
on the ground, either by counting all parked vehicles or by counting
empty spaces and deducting them from a total available inventory,
resulted in considerable error and were very time.consuming. In a
few minutes several aerial photos can be taken which will provide a
permanent record of parked vehicles that can be counted and re-
counted for accuracy.
Weather and other circumstances permitting, the aerial photo-
graphs were taken on the Friday following Thanksgiving, and on
one (and in certain cases, two or three) of the Saturdays between
Thanksgiving and Christmas in 1973. 1974, and 1975. Whenever
possible. the peak parking accumulation data secured for the pre-
Christmas period from the aerial photographs were augmented by
manual or automatic recording of traffic movements to and from the
regional centers for comparison with past traffic volume charac-
teristics. The occupied GLA of the regional shopping centers in-
cluded in the survey was obtained from the center managers or de-
velopers. It was also confirmed with representatives of various
shopping centers that the aerial photos included all employee park-
ing areas related to the particular centers surveyed.
Results
During 1973, 1974. and 1975, the various offices of Barton-Aschman
Associates obtained peak parking accumulation data on one or
more of 21 different days at 32 regional shopping centers (each hav-
ing a gross leasabie area of at least BOO,OOO square feet), in five met-
ropolitan areas-Washington. D.C.; Chicago. Illinois; Min.
neapolis!St. Paul. Minnesota; and San FranclSCOtOakland and Los
Angeles. California. These data represented 141 total parking ac-
cumulation counts of centers having 800.000 square feet of occupied
GLA,
FIGURE 4
HOURLY PARKING DEMANDS
"
00
..
..
"
"
'.
"
"
..oU_O''''fau
On Table 1, the observed parking demand ratIOS (parked vehicles
counted per 1,000 square feet of occupied GLAl are listed by geo-
graphical area, occupied GLA, and the date and the day surveyed.
Figure 5, more graphically illustrates the sU1"\'ey results. In addi-
tion, aerial photos of peak parking accumulations at regional cen-
ters during the 19i6 Thanksgiving to Christmas peak retail sales
period were also taken. A parking count of 13 selected centers, four
in the Washington, 0 C. area, four near Chicago, two in the
Minneapolis-St. Paul area. and three in the San Francisco-Oakland
area was completed for 1976 as well. These counts are also marked
on Figure 5, and they are listed by geographlCal area in Table 2.
In January 1965, there were only 73 shopping centers in the United
States with a gross leasable area exceeding 800,000 squ<lre feet
(Chain Store Age, May 1966), Recent estimates published by Shop-
ping Center World indicate that by the end of 1974, there were 24.9
shopping centers with a gross leasable area exceeding 800,000
square feet in the United States and Canada. Thus, this research
study, in which 32 such centers were suno-eyed, is based upon a
sample size of about 13 percent. As shown by the results of the data
analysis, less than 8 percent of the parking accumulation counts
exceeded or equaled the current standard of 5.5. Thirty-nine per-
cent of the parking demand ratios determined fell between 4.0 and
5.0. and nearly 32 percent were less than 4.0.
The average parking demand ratio of all 141 parkmg accumulation
counts was 4.4. This is quite significant considering that study days
covered not only the highest sales and traffic days of the year, but
also covered all the Saturdays before Chnstmas which were in the 7
highest sales days of the year. Only the Saturday after Thanksgiving
(which was the 15th highest sales day and the 6th highest traffic
day) did not fall in the 10 highest sales days. Of the 4, peak parking
accumulations observed on the Friday following Thank5giving in
1973, 1974, and 1975 in particular, only nine resulted in parking
demand ratios equal to or exceeding 5.0 parked vehicles per 1.000
square feet of occupied pass. leasable area.
Following the compj~t10n of the study, a concern \,\:a$ expresc;ed
that the fuel shortage which uccurred m eJrly 1974 and fuel rrlces
VI.'hich ha\'e continued to rise mi!:;ht have had J. sisnifil.Jnt effect on
the parkins de:r.ands durin!:; ~he 197"'; pre-ChriqmJ.s Fcn0d It ,1p-
pears that this effect WJ.S negligible for two reasons. The first reason
is the result of an analYSIS of the monthly saj~s of motor fuel in the
l'mted StJtes. Although fuel sales were below 1973 ievels tor Jlmost
all of the hrst 10 months (If 1 Ct7..L by ~o\"em1::h>r J~;4 fuel SJJt:'S had
C-3
11~
Table 1
SUMMARY OF PARKING DEMAND SURVEY
OCCUPI ED OCCUPI ED OCCuPiED
GlA GlA GlA
(1,000', SURVEY DEMAND 0.000', SURVEY DEMAND .(1.000'~ SURVEY DEMAND
SQ. Ft.l DATE DAY RATtO 1 Sa. Ft.l DATE DAY RATIO 1 Sq. Ft.) DATE DAY RATIO 1
eal Co.rt: 11-24-73 S~t. 2.9 1,159 12-13.15 So" 1.185 11-23.73 FrL 3,B
B59 4,4
B59 12.15-73 Sol, 4,4 T,123 12.8.73 SolI. 4~6 1,185 "-24.73 S..t. 3,5
859 ".29.74 Fri. 3~5 \,123 12.22.73 Sol~ 4,0 1,1a5 12.15.73 Sat. 4,6
B59 12.2'-'4 $,t. 4,' 1,123 12.21.74 Sol, 3~5 1,213 11.)!).74 S.t. '~4
859 11.28.75 Fri. 3,9 12-13.75 Sol,
859 11.29.7S Sat. 3,' 1,122 3,9 1,214 11.28.15 FrI. ,~,
859 12.20-75 Sat. 4,4 1,111 12.22-73 Sol, 5,' 1,214 12.13.75 S.,. 33
1.111 11.29.74 Fri. 3,' 1.214 12-20.75 Sat. 3.4
1,165 11.24.73 Sol~ 4,3
1,165 12.15-73 Sol, 50 1,111 12.21.74 Sat. 4,3 1,334 11.23.73 Fri. 5,5
1,165 11.29.'4 Fri. 4,3 1.111 1'.28.75 Fri. 3~9 1.334 11.24-73 S.t. 3,'
1,165 12.21.74 Sat. 4,5 1,111 12.13.75 So.. 3,' 1,334 12.15-73 So.. 4,1
1,165 11.28-75 Frs. 4,4 1,208 12.8-73 So, 54 1,346 11.30.74 Sil. 4,0
1,165 11.29-75 5.at. 4,6 1,208 12.15-73 s",~ 4,5 1,366 11.28.75 Fri. 43
1,165 12.2{).75 Sol, 48 1,208 12.22.73 S.at. 5,' 1,366 12.13.75 Sit. 38
900 11.24.73 So.. 5,' 1.208 11.29.74 Fri. 5,3 1,366 12.2Q.75 Sit. 4~1
900 12.15-73 s"" 5,' 1,208 12.21.74 Sol, 4,9 800 11.29.74 FT.. 3~'
900 11.29-74 Fri. 5,9 1,208 11.28-75 Fri 4,8 4,3
800 12.14.74 Sit.
900 12.21.74 S~,. 5,5 1,208 12.13.75 Sit. 4,' 900 ".28.75 Fri. 3,'
1.100 11.28-75 Fn. 5~0 1,159 12.8-73 5.[. 2.7 800 12.20.75 Sit. 5.4
\,100 11.29.75 SoIt. 4,8 1,159 12.22.]3 So.. 3,' 816 11.28.75 Fr.. ',1
1,100 11.24.73 Soil. 4~8 1,198 11.29.74 Fri. '.0 818 12.20.75 Sat. 3,1
1.100 12.'5:73 Sat. 4.4 1,198 12.21.74 s",~ ,,' 5,4
827 12.'4.74 So..
1,100 11.29-74 Fri. 4,' 1,236 11.28.75 Fri. '~7 827 11.28.75 Fri. 4,6
1.100 12.21-74 Sit. 4,9 1,236 12.13.75 S.at. 2.7 627 12.20.75 s".. 60
1.250 ".28.75 Fri. 4,5 1,000 IZ.21.74 So.. 53 836 ".29.74 Fri. ,,'
12'" 11.29-75 So, 4~' 1,250 12.13.75 Sot~ 4,3 836 12.t..74 So, 3~5
869 Midwest 11.23.73 Fri. 5.3 945 12.13.75 S.lI. 49 836 \1.28.75 Fri. 3~5
669 12.15.73 Sat. 5,1 1,280 12.8.73 So.. 5,6 836 1220.75 s"" 4,1
671 11.29-74 Fri. 5~' 1,280 12.22.73 Sit. 5~3 953 11.29.74 ;:,1. U
871 12.21.74 Sit. 4~8 1,280 11.29-74 Fri. 46 953 12.14-74 Sat. 4,5
1,ZM 12.21.74 Sit. 5,3 953 12.21.74 Sol, 4,'
890 12.8.73 Sat. 4~1 1.2SO. ".28.75 FfI. 953 11.28.75 Fri. 40
5~1
890 12.21.74 Sat. 3,1 953 12,2().75 Sit. 4~8
1,280 12.13.75 S.at. 45
9'" 12.13.75 Sit. 3~' 1,035 12.14.74 s"" 3,4
1.610 12.8.73 Sol, 5,3
1,003 12.22.73 Sat. 4,4 1.610 12.22.73 Sat. 5~3 1,035 11.28-75 Frl. 5~'
1003 11-29-74 Fri. 4,8 1.035 12.20.75 S.. 5,6
1003 12.21.74 Su, 5,3 1.734 11.29.74 Frl, 5~3
12.13.75 So.. 55 1,734 12.21.74 So, 3,8 1.067 12.20.75 SolI. 55
1,003
11.23.73 FfI, 4,8 1.858 12.13.75 Sit, 5.' 1,132 11.2875 Fri. 3~0
1.108 1.132 12.20.75 Sen. 3,9
1 108 12.15.73 Sit. 4,6 948 Wen Cout, 1.23.73 Fr<. 4,4
1 108 11.29-74 Fri. 4~' 948 11.24.73 Sit. 3~8 1.175 11.29-74 Fn. 5,6
1,108 12.21.74 Sit. 4,' 948 12.15-73 So.. 3,9 1,175 11.28.75 Fri. 5~3
1,096 12.8-73 S.at. 4,' 948 11.30.74 So, 3,0 1,175 12.20.75 So, 5~'
1,096 12.22.73 Sit. 4,5 948 11,28.75 FrI, 3,6 1,194 11.29.74 ;:11 3,'
1.096 11.29.74 Fri. 3-' 948 12.2Q.75 Sat. 3~5 1.194 12.14.74 Sit. 3,6
952 11.23.73 Fri, 4~3 1.194 11.28.75 Fri. 43
852 11.24.73 SIt_ 4,3 1,194 12.20.75 So, 5~'
1 Demand Ratio. Number of pirlf.ed vehicles per 852 11.3(}74 Sit. 48 1,34\ 11.29.74 Fri. 4,'
1.000 sQuare feet af occupied gross Iusible aru. 852 11-28.75 Ff1. 4.4 1,341 12.14.74 Sa!. 4~6
852 12.20.75 Sat. 5,' 1,341 ".28.75 Fn 5,3
1,341 12.20.75 So.. 5,3
again begun to exceed those recorded in the same month of the
preceding year, The second reason is exemplified by a comparison
of the average parking demand ratios of the 3 survey years which
""ere .;'5, 4.3, and 4.3. respectively for 1973, 1974, and 1975. The
median or mean parking demand ratio for the peak parking ac.
cumulations observed during all 3 years was 4.4 parked vehicles per
1.000 square feet of occupied gross leasable area. The mean ratio far
the observations was 4,5 in 1973, ..1.5 in 1974, and 4"; in 1975.
Conclusions
This research study has revealed that more than 75 pt!rcent of the
parking accumuli\tians observed dunng the highest sales and tra;.
tic ,1(ti....\ ty days of 3 recent years (1973, 1974. 1975) resulted in a dJ.lly
reak parking demand ratio ai 5.0 or less cars parked per 1,OUO
]]8
square feet of GLA. Advance tabulations, as p!"eviously shown in
Table 2, of even more current data from the 19i6 pre-Christmas
peak shopping period are further confirmation of these results.
Analysis of hourly p,lfking .Kcumulations dunng peak retail sales
and peak traffic days dearly Indicates that even on those days when
the peak parking demand ~Jtio at a fe\\' cente!"5 e'l(ceeded 5.0, the 5.0
ratia W;)S exceeded ior F'fl1bJbl.... nl' more than 3 h(I'..:rs during the
day, or :ess than O. j pt.'!"ccnt of the arpro'im.1tely 3.(-00 ho\.:!"~ of
aperat:o:1 of the resi0n.J.l c~'r'ttC'r:- dunng .1 yo.;o,~r 6,I!'ed on J rrll1rt:
detailed J.nJI\'~i:. in i1"~..:!i\'!"::l..ial n1CI:"l'F'l11i:::n Jrt..'.1S tht> p.3rkjns ~.1tJl'
c0uid prob..ll'i\' Qt' t'''''_'l"I Ii.Jr:\1l'~ ft;>duCl'l1
A sismih:anl CC'.;L~<..::--'-Jtlc,n ," i""d (l1Ulj :"l..' ,1(\~l.:\.t..'d. l'\"en h' reo
duclng the par;"ln~ fc:,,-' rrl1;n::' :- rLl ;.0 ThiS ~"r,.j S;.\"lnP ,1;' J. ~esult
C-4
of matching surface parking area to demand could be behol.'een 4
acres for a centeraf SOO,OOOsquare feet of GLA to as much as 10 acres
for some of the larger centers which have or approach 2,000.000
square feet of GLA. The land and construction cost savings by not
having to provide excess and little or unused surface parking is sig-
nificant. The cost savings by eliminating excessive parking be-
comes even more significant if surface parking land is not available
and a parking deck must be considered. The adoption of a lower
parking ratio would be especially beneficial in the case of existing
centers, and in particular. those centers which are to be expanded or
modified to include ancillary urban center facilities such as librar-
ies, museums. hotels, general purpose offices, and governmental
offices.
At existing centers, lower parking ratios would pennit not only the
development of additional retail sales space or other compatible
uses, but also the replacement of bleak. dirt-collecting, costly-to-
maintain sections oC the parking area with expanded landscaping Or
other amenities. Similar advantages would be possible for pro-
posed new developments.
Examples of compatible or ancillary development which could be
provided on the sites of proposed new centers. or which could oc-
. cupy surplus parking a,rea at existing centers, include public and
private offices, movie theaters, hotels or motels. freestanding bev-
erage or specialty Cood stores, and drive.in banks. The relatively
large expanses of paving normally provided within shopping cen-
ter parking lots would be particularly well suited to providing the
commodious vehicle queuing capacity which is a nonnal require-
ment of a drive-in bank. However, consideration would have to be
given to the integration of such a queuing area with the other ac-
cess, circulation, and parking requisites of the site; cons~uently,
overall site design standards must be carefully formulated,
"tested," and adhered to.
Grants of narrow strips ofJand along site boundaries could be made
to public authorities forthe purpose of widening roads and improv-
ing the landscaped interface between the center and the rest of the
community. In many cases, this would not only contribute to an
improved relationship between the center and the community but
aiso result in the improved visual impact 0(, and more efficient ac-
cess to, the center itself.
FIGURE 5
PEAK PARKING RATIOS
< "'t-;c-_
_ 50 xx_
:
~.
~ 40
:0:"'-
X.'__..
X.-'"
,;
,
)Q
10
Table 2
SUMMARY OF 1976 PARKING DEMAND SURVEY
(Advance Tabulations)
OCCUPIED
GLA
(1000's
Sq, Ft)
859 11-26,76 Fri, 3,1
900 11-26-76 Fri, 5,9
900 11-26-76 Fri, 5,9
1,100 11-26-76 Fri, 5,2
1,165 11.26-76 Fri, 4,0
871 11-26-76 Fri, 4,5
945 12-11-76 Sat. 4,6
1,003 12-11-76 Sat. 5,0
1,108 11-26-76 Fri. 4,0
1,159 12-11-76 Sat. 3,6
1,178 12-11-76 Sat. 5,0
852 11-26- 76 Fri, 4.7
1,214 11-26-76 Fri, 4,7
1,367 11-26-76 Fri. 3.2
, Demand Ratio=Number of parked vehicles per 1,000
square feet of occupied gross leasable area~
GEOGRAPHIC
AREA
SURVEY
DATE DAY
DEMAND
RATIO'
East Coast
Midwest
West Coast
In sele.cted cases, commuter "park-and-ride" parking facilities can
be developed to serve mass transit stations, either adjacent to or
integrated within the center. In this case, however, care would have
to be exercised in formulating the plan to ensure that users of one
category of parking space do not usurp the other. For example. it
could be economically disastrous for the center tenants if prime cus-
tomer parking areas were regularly occupied by commuters. Hence,
the commuter parking area would have to be dearly segregated
from prime customer parking areas. Fortunately, because the bul:-'
of commuters would arrive in the morning long before most shop-
pers, it may even be possible to close certain shopper parking access
points until. say, 9:00 a.m.
OaV11..'~tVltd ,oC!"Qlt
~"aavl !<)nQW'''~ Tn~""'9'.'''9 D~y
,no 5111"':!....l l)otlwtt., T"I"~;9"""Q
.,.,u C""~l m<I~ ," 1 9 7:3. 1 974 i "<I ~ S 75
X. I'<t\",,~ 01 ""o.~"u TIU"ii"O">
01 1976 S.., .~V\
xx.x......_
;0:........
,..
:\....
;>0
00
'. .,1< :::' (,:t,S.E:<:'1\.':" T 'u~,
'0
C-5
~,']
. ~.' C
JIG
On peak days, with employee parking moved outside of a shopping
center's contiguous parking areas, the peak parking demand gener-
ated at the center could be reduced by another 1.0 to 1.S spaces per
1,OOOsquare feet ofGtA. This single modification would reduce the
peak parking ratio for customers only to between 3.5 and 4.0 spaces
per 1.000 square feet of GtA.
Some of the current and emerging directions in land use develop-
ment and public and private planning philosophy which could
make the parking ratio reductions just discussed a near future pas.
sibihty include:
. The continuing development of new and expanded "conven-
tional" public transit services.
. The potential of remote-parking~and-shuttle arrangements.
Admittedly. the most successful of these to date are in-city sys-
tems, such as the unique M &: 0 subway in Fort Worth, Texas.
. Low-pollution products of innovative technology, e.g.,
monorail and PRT, which could link retail. commerciaL institu-
tional. and other components of new and expanded diversified
urban centers.
Recommendations
Based on the fmding-s of this research study, the following recom-
mendations are made:
. Existing centers which have had a peak parking demand less
than their present parking supply should be allowed, and in
fact encouraged, to develop additional retail space andJorother
compatible land uses or amenities within the confines of the
shopping center proper in order to use the currently under-
utilized parking areas.
. 5.0 parking spaces per 1,000 square feet of gross leasable area
would be, in general, a valid national maximum as a basis for
current planning for new, existing, and expanding regional
shopping centers .....hich have, or.....ill have, a GLA greater than
800,000 square feet. In fact, a reduction to 4.0 spaces per 1.000
square feet of GLA is recommended in cases where employee-
owned vehicles can be directed by prior agreement to off-site
parking facilities during peak shopping periods such as the
Thanksgiving-to-Christmas period, pre-Easter. Mother's Day.
and other peak sales days.
. With additional documentation to support the above recom-
mendations, a further number of centers may be able to realize
a greater reduction in the recommended 5.0 standard. Such
findings or data support may be a result of changes in the com.
petitive market area and relocation of employees to other park-
ing areas during peak shopping days.
. That continuing research be undertaken with the objective of
establishing well-documented parking ratios for shopping
centers of various sizes and functions--major regional centers.
800,000 square feet ofGLA and over; large community centers,
400,000 to 800,000 square feet of GLA; convenimce centers of
smaller sizes; fashion centers; theme centers; centers with and
without large food markets; and for existing and proposed cen-
ters of various sizes and functions located in various geo-
graphic and major metropolitan areas in r-.:orth America.
~
C-6
120
. That both governmental agencies and private developer
groups review the results of this research and the results of the
continued research recommended above. Following debate,
governmental agencies should make the indicated changes in
zoning ordinances to permit a more efficient use of land re-
sources in the vicinity of major concentrations of retail and
commercial development.
Acceptance of the above recommendations would
. result in significant reductions in development and mainte-
nance costs; allow for the dlversification of on-site commercial
and institutional facilities;
. permit the provision of improved amenities (landscaping ex-
tensive enough to be used as a park or protected walkway sys.
tem); and, by virtue of the latitude afforded by the increased
space made available. make it possible to improve the effi-
ciency and safety of the access. circulation, and parking sys~
tern; and
. continue to maintain the economic viability of the center not
only for the developenowner but for the muniopality as well
(Measuring the Fiscllllmpaet of a Shopping Center on Its Commu-
nity, Michael S. Levin, Barton-Aschman Associates. Inc.).
Clearly, one magic ratio cannot be applicable to all shopping centers
throughout North America, regardless of geographic location; met-
ropolitan area population; the GtA of centers; the constitution of
centers (such as number of anchor stores, national anchors versus
locaJ anchors, or presence or absence of a full-line food market);
uniqueness of centers (is it the only one of its size and diversity
senring an entire urban area and its hinterland, oris it but one ofa
well-distributed series of centers serving a large metropolitan area);
availability and type of public transit service; age an&or density of
residential district .....ithin a center's market area; and the range of
family income levels represented within a center's market area.
During the research study significant differences were noted in the
peak parking demane ratios for shopping centers of similar size.
function, and composition, but in different geographic and demo-
graphic areas of the United States. Barton-Aschman Assodates has
not been able either to make a sufficient number of surveys of in.
dividual centers or to analyze the available data in sufficient depth
to fonn definitive conclusions regarding these geographic dif.
ferences. Hence. firm parking recommendations relatmg to dif.
ferent geographic or metropolitan areas cannot be mad~ at this
juncture. However, the data we have managed to distill during the
analytical process exhibited differences that are significant enough
to warrant continued data gathering and analysis.
This artIcle is baud Lm research t.<ndl'r/aker. Jointly by the officcs of
Barton-Asd:man AssoClatcs. [ne.. IClcatrd In El.'ar.ston, lllinois; ~,\'ash-
ington, D c.; ,\1innrapoIis.St. Paul, Mmnesota; Los Angelrs arId San
Jos~. California. Richard C. Can. srllior vice president of the firm. U'QS
prOleet coordinator
i:
I,
, ,
,~ i
Special Report 125
-
1
J
] Parking
']
Principles
'1
'l
T
.!
"
1 I
f
'I t I
I II
, I'
,
j [
I
I
" ~
,
r
l
I
t
f
I I
II Highway Research Beard
[ I National Research Council
, : National Academy of Sciences
1 National Ac::demy of Engineering
,
D-1
i
I
A,
"
J
1
1
1
]
,
]
]
J
J
:J
:1
,)
1
:]
1
_;s
1
~
A,
,
,'t
Hi,hway RtscJ.rch Board Special Report No. 1:'.5
PARKING PRINCIPLES
(~~ I bY,~thd)";lliOnaj ....cademy of Sciences, ....11 rights "served
" Libr:uy of C"ngms Catalog Card So, 72-17J639
---.-
ISBS 0.J09-01913,J
Price S I 0.00 dothbound
S 8,00 pa~rbound
A vailablc (rom
HiShw3Y Research Board
Nallonal Academy of s.:iences
:'101 Con~tiru{ion ......enue 'S.\V.
W3shjn~ton. D.C. 20418
PriMcd in the L'nilcd Slates of America
D-2
97
. ; -" ..~-~._--- ---.
r:
lOCATION AND DESIGN
_- '.-. ",,"----r-'
I
J
'.
. -. ~~.
~.:. .
r ,.,..,
(.
~. .......
.:.\ ,". ."
'~"'.9"
, .
'.
. -
J
.' .
.' .
.' .......:.-7
/ /'~..
~ . ..... :
-
J
.-
.
I
~
.. .
, '.
~., .~
,/
1
I
...
, "
"
.' ,
..,,:.
, , /
J
J
t : ~. ,
l
, ...
.~:../-
/"
....... .
... ~ .
'..,,"" .
.
'/
/,
^/.'
,I.
-:
(/,......
,/
,/
....'"
, -
'.'
'.
.j
.
'"
..,,~. .,/',
"/ /,.."
. ."'",.-", , ." "
...". ......_ ./ _ ~. JIl:....-.:
.~--~
'.
....'
.'
,
<
...
...
-..,.
:.....
'"
/...::r
'..
.J", .~
.'"
~.. : . '. :;.-: :...... -....
, ~ / / '''~'' l", ....4 .
-.:.. ..'....,., "
-.
...;....:
...-:"
'_ I: ~.
':d
/, )
.:" ~
'1
j
1
. ~,.
'.
.... ~....
':'..-
. .:
. /' '::
.. ". .
.{:
..!
, -
'. .
:...._"...
/'-.
."''''"-
... '
""lIi,.
,
,
'-
, -
-,;/
>.'
,
j
.
". ':' i
,~-..,."'-
~ ~)
, .
.
,
"
- ;:.....
.' ~:~..:..:: ~:-:
....... :.,.-'-
,. .
~
~/
,
./
,/,
,/'
., /
.,/. ~
;. '/
.......: ;
'1
......,
, .'
- ,
"~:--
.,
.~
.'~
.'
,
./ '
,
/,
1
I,
,
'-
'. ,
,~
.~..~..~.
''-
This small city had a parking shorra<;e. and iu CaD had hisloricaily dt:ve{op~d on borh s:.::'t;
of 11r~ ,il.'~", A tuatm~"l jar ooth problems ......as sllppiit!d by :his (larking "bricse".
..
ings. Frequently IJrge portions of the
ground floor are devoted to retail estab.
lishments, and parking is loc::lted above or
below ground level. Other floors r:l::lY con.
t:lin offices. clinics. hotels, or apartments,
In such developments. :he land cost
chargeablc to parking is greJtly rduced,
A severe penJlty may be inrroducd, how-
ever, in the l:lyout Jnu operJting ~mciency
of the g~rJgc. Pr::ctic:ll column spJcings
for parking may not be economi>:Jlly ac.
c.:ptllble for other building us~s Jbovc or
below the parkin~ levels,
Such prockms can be minimized by
orefu! con$iJer~licn of stn.:c:ur:..l[ r.eeds.
A Howard 10hn,on ~lotor Hotel In Chi.
c.:Jgo W.JS d.:si~n.:d for 396 un:!s to be
located on top of a 1 O.sr'1rY r:Irkin~
~Jr;I;;~ h~~vlng 3~U sr:1(.:':s (..;). F urih.:r~
!
,!
.
~
..
.
.
D-3
more, the self.service gar:Jge W:JS cesig~::J
fer clear.span (coluf!'n.iree parking anJ
aisle area) construction,
SURFACE PARKI~G DESrG~
.\losl of the ,basic principl>:s of pJrkin~
layout c:m be illustr::ltt:d by .J re...ie'.\' or
sur:Jc:: loc cesign, s.t:Ja lGsi ,-:}iSlr;__~i~~::-..
sions and ;lrrJng:'::";1e~:s. :,cnzon:Jl clr::;.
lJ.ticn patterns, [~$~rvoir ~e:.::is, :}.:-:d ~:'::r:'.
exit revenu~ con:rois .:t:~ simil.:tr fer :.::,
:J.nd g;J.r::lg~s. Thl.: $p~~:~r elcm~:-::5 If'l:rc-
duccd by g:1:~~~s (colu:iins. r:J.~?s. \"c::";.
CJl circubrluo pJ::crns, daytime ;'~~:I"~,
::JnJ vl.;n:il:ltion) :lie co\::r:li s':p:J.r:J.~..:i:. ::1
,Ill.: P:lr~JI1~ Struc:ur..: :-....::t:l)n In (;-:"
<..:!I~lp'~r.
93
PARKll'OG PR1NC1PLES
~.
I
j
Relationship Between Design and
Operation
The opcr~tion of ~ parking f~cility is
greatly influenced by its design. The de-
sign elements ~nd their assoei~ted opcr~-
tional fe~tures m~y be identified in succes-
sive steps as follows:
1. Vehicul~r ~ccess from the street sys-
tem (entry driveway);
2. Search for a parking staU (circula-
tion and/or access aisles);
3, Maneuver space to enter the stall
(access aisle);
4. Sufficient stall size to accommodate
the vehicle's length and width plus space
to open car doors wide enough to enter
aod leave vehicle;
5. Pedestrian access to and from the
faciliry boundary (usually via the aisles);
6, :-'hneuvcr space to e~it from the
parking stall (access aisles);
7, Routing to leave the focility (access
and circubtion aisles); and
8. Vehicular egress to the street sys-
tem (e~it driveway),
The simplest form of off-street parking
is the single stall at a 'home, Assuming a
straight driveway. steps 1 and S use the
same lane and curb cut opening, Steps 2
and 7 are rudimentary. Step 6 usually
involves backing out into the public s:reet
or alley. as part of 7 and 8. Herein lies
the essential difference bCl'o,een low-vol-
ume parking and ,...hat generally should be
practiced in facilities designed to handle
more th;Jn t\....o or three c:us. _E:t~~?t along
alleys, the larger lotsshould have_all park-
in!! and ~_~..L~lJg_.J!!~~_euvers con~~ined
off-street. Frequent backing of cars across
sidewalks and into public s;rcets increases
con;cstion and creJ,tes b~Jrcs.
1
J
1
J
]
I
']
1
...
A
]
J
'1
.J
Stall and Aisle Dimensions
-
In developing the design of a parking
f~cdity. it is CUSlIJmJry to '.\"{.'rk with s:;::!ls.
aisks, and comb,n:Jtions calkd "modules,"
1"
~~
D-4
A complete module is one access aisle
servicing a row of parking on c:lcn side
of the aisle, In some cases partial modules
Jrc us~j where the :lisle only ser,'cs a
sinde one-side row of parking, This ar-
ran-:;ement is ineiiicient and should be
avoitJcd where possible.
The minimum practical stall width
varies principally with turnover (frequency
of stall use) and the e,'pcrience of the
parker, Commercial parking attendants
can park stanlbrd American cars in stalls
:IS narrow as 8,0 ft. but 8,3 to 8,5 ft is a
more common width. With self-parkin~. a
width of 8.5 (for indl.<;.tr;:11 nr C"MrG ~ffi~
pl~y~es) to 9,0 ft (for other public 5;> #-
res,den.tlaL_,::~.~s)_.~~nee:!cd, If P~CK_~~~_S
:~~ecr~~or~tSI\(~~n\~;2~~~'~f\~,~rt6Hf6~~ '~
ft are dcsir~ble. ~
The lon!Z.tcrm tre~d in Ameri~J.n Jut
mobile design hJ.s been tov,:Jrd i:1c::=:lscd
width, Thicker doors ~nd ;ncre~sed num-
b~n of 2-door CJiS hJ.'.'c been in '/O;lJC: ~or
m"n" """rs T'n e ~rV'I'c"1 1........,;t5 ..................,-.1
.... .' ....... w ..J.... ~ ...... ".... ~_...
d " I ~ l'
for oor oot:nmr: SiJJC:: 0'::(\\ e~:i CJ:-S. ::1U
dnver or OJ.sse:1!!-:r ':"":::$5 to the ';::~I::L:S.
CCil'18lnC ro Dr0CL:~:: In OD~tiTI~;:1 s:;:~l
wldth of Joe!;! Y.O [t for ::10'5~ J.~pil::.::l~ICr.S.
It is import<lnt to note that stall ':.;;0:n5
3.r~ men.sured crosS'tY'ise to the vehic!e. If
the mIlis placed,at an ;;ngle of less thon
9D d~~. the widthp~r:.U.c_! to tr:.e _~i~le
must b-e incrc~scd t'roPQ~ion:ltety.
~1;:J.nv en~ine::s arc oi the o~inion tn2.t
r:1Jrkin; of ~ubsrJnd:rd st:.ll widtr.s r~pre-
se:1ts f;!se economy. For eX:l:npk. In
SO-Ft row wiiI typic~!Iy p2.rk about 9 C::lrs
at 90 de~ to the aisle, If the row is :n~rked
for 10 s;JHs of only S-(t width, ov.:r:H.Lr::;
tends cO:1sist~:1tly to !:~e on~ or t',\Q st;jj]s
out of service, Although there is ~,o i~,-
c:=as~ in c:l;J::lci~y by ~h~ s;,,:ost;::-:~;:rd
markin~. there is c::pcrtl.:~it:: for l~r,:!.1:;.
canfusi;n. irritation: ::lnd fC:1dc;~b':;1f.~;ng.
Th~ !e:'l~th (')f :::t:dl s!~ould b: ~;::-'~ri"'lrH\~
y
;JL: [t) :::: l". t.':";:~: ~~,~q'~1 uJ ::!:::I" ~ .., '~:.~...
C.\:1~::~u to u:::,c U:..: :::';'.:c;;. .:.. ,....:~_..: ...;:
t J.,....;u.. (
1
J
I
1
I
~
I
I
I ;
I
I
I
I
I
I
1
I
1
l
LOCATION ....NO DESIGN
I
..
I
\
O-t-E~
lNTERlOCK
I
I c !
!:"LL TO
I
x . SiAll..
INTERLOC~I"C
o
MOOULE
~~OT ACCESSIBLE JNC;:RTAI~ lAYOUTS
F
MOOULE
99
I
T
T
.
-1.
" '
~ I
:'<
I I
I,
,-....( I
,~ ,-
1
I
"
P"R~INC LAYOUT OiMENSIQ.'.S hn I~tl :,]R 9,;:7 51"":'LLS
AT VARIOUS ).:lGEi..E.5
On
OimenSlon OiaC;nm 45' ~i'j. 4)' 90'
Sull w;dth. parallel to aisle .. 12.1 10.4 9~3 9,0
Salll",qth of line 9 :5,0 :2.0 ,0,0 la.5
S~lI d."t" to wall C 1),5 19~0 19.5 18.5
Ais,hl ....id~h betw~ S'ullltnl!$ 0 1~.:J 16,0 2~.O :5,0
SuI! ~e;)ttl. lnterlcclc. E 15.3 17,5 18.6 18.5
Modt.Ile. waU to InterlOCIc. ;: "'~a 52.5 61.3 030
Mod\.:!e. int!r!Oc).Ir'q G 42.5 []]J 51.0 163,0 I
MOCI\lie. ,nCerlOCll. 10 c..uo tac. H 4,,8 50.2 sa,s eo.s
SumQ<< O'VefNng (rvQIClll I ,,0 2,3 2~5 2.5
Oft$el J 5,3 2.1 0,5 0,0
Sotbod< K 11,0 a,3 5,0 0,0
Ct'O'Ual1lt.one......ay L ,,~O 14~0 140 !J..C
Cross a.s.!e. rwO-wav 24,0 24,0 24,0 240
Fillurt 6.2. Slalllayollt tltmtnls.
.
D-5
t1
.
.
t1
..
,
r)
,
"
.
:1
~
f
~ '
.
r
f ,
:
i
I
l
a
.
~
It
it
.
..,
L1.
100'
PARKING PRINCIPLES
(/ I 8,0 ft hJS served this our-pose in post
4 Yl.:.HS. but :J \':!luc ot 18.,) tt IS rt.:..:om-
( mcnot.'tl o\' som..: en\!lne:rs on the OJSIS or
,incn:ascd automoblk SIZ:::S.
These lengths rder to the iongitudinal
dimension oi the sttll!. \Vhen rototed to
angles of less thtln 90 de;. the sttlll dcpth
perpcndicultlr to the aisle increascs to tl
maximum of netlrly 20 ft tlnd then
decreases.
Most ptlrking aisles serve ior both cir-
~culation tlnd tlceess to stalls. Exceptions
concern crosswise or "end-loop" aisles.
The access oisle width required to oIlow
single-poss ptlrking ond unporking r:1oneu-
vers vories principolly with the tlngle oi
parking and secondtlrily with the stoll
width. It is obviously also reltlted to the
stall length, \Vhen dcaling with brge
ftlcHities, most ptlrking designers work
directly, with the combintltions oi stall
depth plus aisle width, or modules.
For 90-deg parking, the tlisle width can
also be reltlted to the proclice oi pull-in
venus back-in porking, Typically, 0 driver
backing into a stoll requires about 4 it less
aisle width, Furthermore, the maneuver
is easier to perform. Unfortunately, the
majority of drivers (bNh male and fe-
male) are reluctant to btlck into porking
stalls. For this reason, pull-in design is the
norm ior practictllly ail facilities.
The total dimensions required for a
parking module ore preduced by adding
together the aisle width plus the sttlil
depths (perpendicubr to the aisle) on
both sides, However. the effective stoll
depth depends on the boundory conditions
of the module, If cor bumpers contoct 0
woll or fence on one or both sides. the
maximum tOltll module requirement is de-
veloped, If there is no boundory bonier
of bumper height. but tires oi parked
cars conlact whed stops or curbing, the
vehicle overhong must be considered. The
curb must be set bock. For 90-dcg pull-in
pJ.cking. th~ s~th;J.ck [0 the inner IJCC
(wheel side) of the curb should be obout
,
i
D-6
2,5 ft. For bock-in opertltion. a 4,0- to
4,5-it setbock of curbing is needed be-
eause of the grcoter retlr overhtlng oi typi-
cal automobiles.
These setbJck dimensions ore not ode-
quate to furnish complete protcction to
any' fences or eeeorative wolls located on
the perimeter. Unusuol overhangs may be
found (such os "Continental" rear enes),
and it is olso possible ior tires to ride up 00
or over the blocks or curbing, When posi-
tive lirnit.:1tion is n:quircd, a bumper ;:on-
t:let b:J.rnt.:r such as a structur:d w~il or
highway guordroil should be used ot the
end oi the stall.
For p:lrking at angles oi less than 90
deg. front bump~r o....erh:ln!;s are r..::du:ed
in proportion to the angle and, for ex-
ample. reach ~ ft at :1 45.dcg ang!e.
Another type oi module. the interlock,
is possible ot the Hatter ongles, There :lre
two types oi interlocks. The more co:r:-
man and more prcf~rable is the ou;;;per.
to-bump..:: .lIT:lngemcnt shown in Fig:lr~
6.2. The other is ::,~ "nested" Interlock: it
can be used <It ~5 deg :md is produced 01'
adj:Jcent aisles h:lving one:.way movements
in the sam: dircc:ion. This arrar.g~::1e~t
requires the bumper of one cJ.r to f2.c: the
fender oi another C:lr, Wheel stops are
necessary for each stall. and. even with
their use, the probobility of vehicular dam-
oge is much greater than ior other park-
ing arrange:nents.
TobIe 6,1 lists desirable desi::'\ dimen.
sions for typlc:li p2.r~In:;' Jng~cs. s~~Il
wlc:hs. :loa mouul~S. In pracu..:::. J. mer;:
f2.0ld plJ.rl\ln~ G?t..:ra::lOn will be :1ch:cvcd It
th~ dim;:nSlons :Ire increJs~d. SiL.:t1t r~~
ductlons In th(: ;,j,lmL:nS;cr.s J.rc :lIs; f~:.si~
ble for low-tur"over ?"rking s~c~ as ::y
emt'loyccs. .:It>J.''u;:cr:t c......c!!~rs. and hO:TIe
owners. In g,JrJ~~s. the r:loduks arc of:::::1
reduced by 2 or 3 ft to :r:inimlz'~ ccn-
struction costs.
Norro"'ed st"l! width for porkin~ on~ks
of ks, than 90 de,: is not deslrae!e 15),
There is J t'l.:!Jtlon between st:Jil \.. it.i~h JiiJ
LOC,\TIO:"f AND DESIG:"I
Table 6,l-Typical parkin? dimensiortS
S1311 St,l1 S"l1
Width Depth Depth
Parking Par,lIel to to Aisle
Angle to Aisle W.II Interlock. Width'
(degrees) (ft) (/1) (/t) (/t)
~
4~
&.J./t ...11 12,0 17,~ 1~,3 13,0
9.0-ft ...11 IV 17,~ 1$,) 12,0
9,~.tt stall 13.4 17,J 1~.3 11.0
.2Q.
<.t ,,11 93 19 I) 17,5 180
9~0.it stall 10..1 190 17.5 16,0
9,5-n st. I. l~, I 15,0
75
S,J.lt ,I,ll g,S 19,) IS,S 1),0
9,O.tt ..,11 9,3 19,) IS.3 23.0
9,~-11 scalI 9,3 19,~ lS,3 22.0
90'
S.)./t litall 3,) 13~) 1&.J 1S,0
IJ,o.ft st:dl 9,0 IS,5 IS,) :6,0
9,5'/1 st.ll 9,5 lU 18,J 1J,O
,
1
,
1
1
..
101
Modules"
W,ll Interlock.
to to
W.II Interlock
I/t) (/t)
4S,O 44,0
47,0 43.0
46,0 42.0
50,0 ~J .r)
5~.O SI,G
5,,0 ;0.1)
64,0 63,0
62.0 61.0
61.0 60,0
65,0 6),0
63,0 I 630 I
62,0 62.0
1
....
,
"1
'\'l
'.
NOT!: T1"Ie~e dime!'\~ior" ~re (or 1;2. !.(t !O:'l2 s[:.11. rn::.:sured pJr:Jl1:i '0 ',e!"1icl:. ~:'ld .:lr: b3sed un re~uits
ot J 5pe:l;.l1 ~tudy 10 e..alU.lle tne ~:ie'~ls .::.~ \..Ltle:.l .Jl~.e: ..Lnd ~;;.J.a '.H..::n iO~ ;;-;: ...:;::.:::::-:: ;:::.:l:.:~; .;l::;;::-:.
shown. The study ""JS conducted In December 1970 by the F::der3.1 H1Sh.....3y AcmlnlSu:1tlon Jnil
Paul C. Box 3nd Associ:l.tes.
...
. Me.1sured bet....een ends of s{:111 lind.
It Rounded to nC.lrcs[ {oot..
.. For b:1cx..in p:uIc.Jna:. J,iSle width mJ,Y be reduc:etJ 4.Q ft..
~
~_1'
aisle width, as shown in Table 6. t. but
the stall width needs are basicallv de.
termined by door.opening clearances.
Only at very nar angles of less than 35
deg wil! doors open ahcad or bdund the
car:s in adjacent staHs, and even then there
can be little reduction in basic st;lll wid;h,
Special dimensions for smail-car ?ark-
ing have occasional ap?lication in the
United States, The percentage or such car:s
varies each year and also somewhat by
geographical locatIon,
The mas; suitable. stall Ien,t.1 for
foreign cars is 15 ft Tahle 6,: gives sev-
eral design dimcnsions for thiS k:I~;h of
vehicle, which may be compared \\lth the
recommcrllht:0ns for stJnoJrJ C:1r5. Ie
shoulJ be n,HeJ Ih:1t onl, \ ('r\' short
American c~rs (1970 :'-.1.1\C"ck ,nJ
J
,..
,
D-7
Hornet) wil! fit into such stalls. So-<:alled
compact cars such as the 1970 Vaiiant.
Falcon, ),!ustang, and ~o\'a require 16-fl
stalls, whereas the 1970 Dart needs a
16,5-fl sta:!.
\\"hen used in U.S. f::cilities. subst:J.r!-
dJrd stJ1l5 fo(' comp~ct C:lrs shot.:ld :;-::-:.
t:rally be grouped. be cony~nic:ne to use,
and have some cc:r.pt:~ling Jt:r:.c:ion ~o
sma!l.c:lr drivers (such :1S r.:cuced. fc~s Jt
comrr.::n:i:lI f:J.ciEties). Th~ ?crce:1t:l;~ <~:
s:n:til st:1l1s shouic ~~ kss ::-::1:1 ~he ?~;-
c~nt:g.c of compJc: c:rs :::\;;~ct::J b...:c:'Js~
U:1c..:r most conJitior',s (h~ Jri','c.:rs \,I,';!i ....:s-.:
some of the full-size stails,
B~c:luSC of th\,.' ?rObl~ms in :H~er:;;:::ln~
to predict ptJ[t;n:i:1.! rn:mb'.:rs cr ..:c:r.;:.:..::
C:HS ~lnJ to cl,mtrt,l :lll.::r pJ.r~ir:~. It i$
usu~\!ly coosiu..:r..:t.i :;00J pel.:t:c..: to l1..:~l::n
')
~
'1
,1
~
1
.
.;/
"
j
:w
i ~ .
!
! .
1
f
(
f
I
S
,;
l
.
'\i
l.
1
,
~
IO~
PARK.i:-';Ci PRINC:PlES
Tahlt. 6.2-Parking JlHlenslanJ for for~ig'r.sl:t' ~'~hidrs (/5.{1 f(ngrh)
Depth
Ais.lc: of Stalls
Leng'h at RiGht
Parking S'all per Angle to Aisle Wall'lo-Wall
Angle Wi~'h Stall Aisle Width ~lodul.
(degr.es) (ft) (fl) Ifi> (ft) ff,)
45 7,5 10,5 16,0 11.0 4),0
60 7,5 8.7 16.7 14,0 47.4
7S 7,5 7,& 16,) liA 50,0
90 7,5 7,5 IS,O ~O,O 50,0
Sot,;ICE: AdJ.pted (rom "Desien o( P:Hl.;,ini G.olr:11:es for Europc:l.n Sco:d,S" (5).
Non: Tn,se me:1SurcmcrlC5 :(e inad~qflau for ,Jver~;e AmC'ric::':1 ccm":1~:S. E.:J::h s:.lJl do:pth should :':
increas.eJ about 1 ft (: ft tot;!.1 for lhe moduic) to .1ccommo..blc the usl.i~1 rJn;:= of Amenc:ln .:am-
p~ct sizn.
every stJll and aisle to handle full-size
cars.
Layout and Circulation
Ideally, parking lots should be lectJngu-
lar with CJrs parked on both sides of Jccess
aisles. For two-way traffic. 90-deg parking
is generJlly used, Thjs tends co be the
most efficient layout if the lot size and
shape are JppropriJte, Furthermore. the
wide aisles Jre more inviting thJn the
narrower ones used for space economy in
flatter angle layouts.
By 1970, the number of licensed women
drivers reached appro~jm:J.te parity with
men, :>lueh concern has been expressed
over difficulties ehJt women have hod in
maneuvering into 90-cteg parking stalls,
However. over 85 percent of the cars pro-
duced in the United Staees during the 1969
model year were delivered with power
steering, Unquestionably, parking at any
angle is made eJsi~r '.vith this pow~r :lssist.
Much of the alleged difficulty With 90-
deg parking has stemmed from inadequate
aisle dimensions, Where proper meJsure.
ments Jre used, a smooth and efficient op-
eration can be achieved, As Wdch h~s
strcs~-::J. thcr~ Jrc Jt kJst cit:ht Jlh Jnla~...:s
in 90.,J.:g I:>yout for slll'pping center
D-8
pJrking (6), H~lf of ehese advontog~s
deal with the greater conve~icnce to the
parker, and the others relate to SJfelY
and opc:r:lting e5cier:cy. For e:r:41mplc) ~r
parking angles of less than 90 Jeg, the
aisles Jre normally one..way. Sometimes
this is desirable, but "regiment:>tlon" of
tiJmC flow within J. porking fJciiity shou:d
be minimized. Funhermore. the nJrrower
on,:.wJY flisies do not pro....id~ iCO:n to pJSS
::1 stJnding or \Voicing vehicle. The one-w:JY
aisks require drivers to cir;:u~.:lte Jt leJ.st
once next to the principJl buildings during
the pattern of enery and e,it. This in-
creases conflict with ped~striJns in the !et
and C:luses unnecessary coo;-estion. It :150
requires driving fre:lter distJnces within
the aisles past other parked vehicles and
increases :he Jccldent poteotiaL Suc::
problems arc reduced with 90-cteg park-
ing. Other advantages. as comp:lred '." i::-:
lesser p~Hking angles. indud~ bc~t~r si;:-::
distance at aisle in(ers:ctlons, iC'J.;~r Jisks
(h~nc: e~s;cr 10C:1:::1; or .:1 p:or~':e': \"e-
hide), and b:::tt';i Jp;JroJc~ VlstJS of .....
shopping c::ntcr buiidings bcc:luse of t~~
wider aisles,
The relaeive etT:eienc;es of various pad,-
ing J:"!gks m:1Y bt: compared by tl:': :1'J:T..
ber of s~uarc kee rc~ui,ed per c"r Spc""
(inc1udin~ tho.: :\..:c~ss :lisle: on :l iull ~1;J":.
Parking ~~Downsb~ed Cars
By Richard I. Strickland
The first phase of car downsizing
, is considered to have been
completed with the 1980 model
cars. It was a little confusing in terms
of intermediate (111" to 120"
wheelbase) and compact (1 01"-11 0"
wheelbase) classifications. For
example, in 1977 Chevrolet had an
intermediate Chevelle and a compact
Nova, In 1978, the Chevelle became
the Malibu and became shorter than
the Nova, In 1980, the Nova is a
Citation and is once again shorter
than the Malibu, At the same time, the
standard Chevrolet in its downsizing
fell into the intermediate class,
To clarify for parking design what
has and is still happening, the table
following compares 1973 car
dimensions with estimated 1983
dimensions, representing completion
of downsizing, The intermediate class
has been deleted as being included in
standard and compact sizes, For
reference the 1980 Citation has a
length of 14,7 feet and a width of 68,3
inches.
'6 lTE Joumal/Novemb.... 1980
Vehicle Size
Standard
Compact
Sub-compact
Length Width
1973 1983 1973 1983
19' 17' 80" 74"
16.5' 1S' 72" 69"
14' 13,5' 69" 65"
CAR SALES AND CAR POPULATION
U,S, car sales in 1979 were
reported by Automotive News to be as
follows:
Luxury
Standard
Intermediate
Compact
Sub-compact
Imported
Total Domestic
5% 6%
15 19
24 31
21 27
13 17
22
100% 100%
Imported cars except for a few
luxury models, are sub-compact size,
In summary of 1979 car sales in the
U,S" 80 percent are now "small"
cars, smaller than standard sized
cars, and 35 percent are sub-
E-1
I
~
'Iii till
rrmT
6:.
L
-
-,
compacts, Further, today's standard
size cars now fall in the intermediate
size wheel base specification.
Car population today, the present
mix of car sizes. is extremely variable
both by geographic area and by type
of parker, For example, counts in the
New York City parking areas have
found sub-compacts to be 20 to 30
percent, compacts/intermediates
around 25 percent and standard size
from 40 to 55 percent of parked
vehicles,
PARKING DESIGN IMPACT
The foregoing review of car
downsizing shows the effect of the
Federal Government's fuel efficiency
standards, Since these standards
were formulated the oil crisis has
continued to worsen so relaxation of
the standards appear unlikely, Even
as oil substitutes are successfully
developed for car propulsion, energy
conservation will dictate smaller cars
for transportation efficiency, Thus,
operators and designers of parking
faCilities should consider what
I
\
,
\
r
I
changes they might make to improve
space use and parking economies.
The following should be
considered:
. Increasing use of small cars will
permit reduced dimensions of parking
units and resultant increases in the
capacity of parking areas.
. Pre-downsizing large cars must
be accommodated for 12 to 15 years
into the mid-1990's,
. New parking facilities, especially
garages. should be designed so that
parking layouts can be revised to take
advantage of reduced needs per car
space,
. Prior to general reduction in the
size of parking units, more capacity
would be POssible if it is feasible to
segregate smail cars,
. An alternate interim strategy
would be to reduce the width of
spaces assuming that users would
park next to vehicles that would allow
usual inter-car clearance.
PARKING LAYOUT VERSUS CAR
SIZE
To aid in parking deSign
considerations. the data below
compares parking dimensions for
various size cars. For this comparison,
a present parking standard for 90.
parking of 8' .6" wide spaces and a
60' unit bay was used. This 8'.6" wide
space provides a 22" clearance
between large cars, The alternate
deSigns provide this 22" minimum
clearance and the unit depthS are
based on reference and fieid studies,
This table permits determination of
parking efficiency with alternate
layouts as compared to a present
standard. For example:
. When it is possible in the 1990's
10 change to the Future Standard that
will adequately accommodate
downsized cars, a 1 .1'6 space index
results. or a 16 percent increase in
capacity over the Present Standard,
. Where it is possible to provide a
Pkg, Car
Parking Unit Unit Lgth.
Present Standard-90o 60' 191
Future Standard--90o 55' 17'
Compact-go. 55' 16.5'
Sub-comp8cl_90. 48' 14'
lnt&tirn--650 55' 1 9'
Interim--90. 60' 19'
separate sUb-compact area, a 42
percent increase Over standard size
parking replaced is POssible.
. When it is desired to build a
facility today with good effiCiency for
downsized cars of the 1990's, angle
parking can initially be used in a
shortened unit bay and then
converted to right angle in the 1 S90's.
Parking efficiency Would be about the
same today and a 16 percent increase
in capacity would ultimately be
Possible. One caution is noted, a 15'
aisle in the angle layout would not
permit by-pass in the aisle as is
Possible in the right angle 22' aisles,
. When small cars are found !o be
about 50 percent of the cars in a
parking facility, simply reducing the
width of the spaces from 8,5' to 8'
would allow a 6 percent increase in
spaces, This design would not allow
22" between side-by-side 80" wide
cars.
SEGREGATED SMALL CAR
PARKING AREA CONTROL
If separate sections for small cars
are established in parking lots, a
critical factor to obtain increased
capacity is full utilization of the small
car sections, Two approaches to the
establishment of a small car parking
section are possible:
1, The small car section wouid be
phYSically separate from the general
lot with a lower parking fee to attract
use.
2, The small car section would be
remarked in the general lot and its use
would depend on voluntary use by
small car drivers.
Several considerations appear to
discourage the first approach--that
lower parking rates be used to
segregate small car parkers:
. A more complex set of parking
rates would be necessary and the
increments between the rates would
be small,
. Fragmented parking areas would
Stan
Width
8.5'
8,0'
8,0'
7,5',
8.5'
8.0'
Aisle
(Car
to
Car)
22'
22'
22'
20'
15'
22'
Space Index
Stalls Per
255tt.'
1.00
1,16
1.16
1,42
0,99
,1.06
Area
PM Car
Stan +
Yz Aisle
255 sq,ft,
220
220
180
258
240
E-2
foster operating problems of revenue
security and of diversion from filled lot
sections.
. Loss in parking revenue appears
probable as lower rates needed to
attract small c,!r parkers would likely
cancel the revenue gain from more
spaces, For example, a $2 daily rate
in a lot for a small car would result in
less revenue from 4 spaces than a $3
rate would provide on 3 regular
spaces replaced.
The second approach, of remarked
sections within general lots and no
financial advantage to small car
parkers, would require three key
features:
. The small car section must have
convenience of car and pedestrian
access to attract small car users. It is
assumed that today's need to save
energy makes it publicly acceptable to
pOSition small car areas to provide this
convenience as long as acceptable
service is provided to all parkers,
. The proper use of the small car
section should be self-enforcing to
avoid added operating costs and
misuse that lessen capacity gains or
patron service. The small car parking
section should be markedly different
in parking dimension from standard
spaces to discourage other parkers.
While clear and distinctive signing
should be provided to identify small
car sections, the large car user must
find the small car section
unacceptable for his use,
. The small car section must be
sized so that it always fills before the
entire lot. Otherwise, large cars will be
forced to misuse the small car ataa.
II is concluded that the small car
section should be designed for sub-
compact size cars for the following
reasons:
. Sub--compact size cars are now
present in significant quantity, up to
30 percent, and represent a stabilized
minimum car size for continuing fuel
economy forced by the Federal
Government. Remarking of about 30
percent of a lot's capacity to sub-
compact size units will add about 10
percent to the entire lot's capacity,
This Change can be made immediately
with further conversion as demand
permits. In contrast, about 70 percent
of a lot would have to be converted to
compact size units for the same
increase in capacity.
. The markedly smaller sub-
".
compact size units (a full 1 0' shorter
in length of 2 stalls and aisle, and one
foot narrower in stall width) would be
self-enforcing to a maximum degree.
Inspection of lots of this design found
negiigible misuse by larger cars.
. The sub-compact car sections. if
found successful, can be retained in
future revision of parking dimensions
in the remaining area of the lots, It is
Iikeiy that atter 1995, few cars will be
made larger than teday's larger
compact cars, Thus, the installation of
sub-compact areas could be followed
by gradual expansion of these areas
based on demand. and then in the
1990's, a reduction in the size of the
remaining parking units can be made
when compact car size units will
satisfactorily serve all cars.
SUMMARY
Energy crisis car downsizing is
proceeding on schedule with the
Federai Government's fuel efficiency
improvement standards, U,S. car
sales in 1979 including imports. were
Qver 75 percent small cars, Big cars'
have become intermediates as that
class is joining the compacts, arid
over 33 percent of U,S, sales are now
s~pacts"--' ,- -...,,_.,
'T~gra<!ual downsizing of CAr~ and
d~m:e of today's big cars will
not permit a general reduction in
parking unit dimensions for clo~e to
15 years, At that time, an increase in
Capacity of about 16 percent would
result trom use of a 55' rather than an
existing 60' parking unit. In today's
new facilities, especially garages,
consideration should be given to
parking designs that will permit
efficient parking layouts for the
downsized cars of the 1990' s.
Interim parking benefits trom the
increasing number of small cars is
possible by segregating small cars.
Alternately, reduction in space widths
affords some increase.
A segregated sUb-compact area
prOVid'es an increase of about 40
percent over standard car spaces
replaced, It does not appear desirable
to us~ parking rate differences a,nd
accesS controls to establish a small
car area, Thus, it appears the best
means to increase parking capacity
immediately is to remark sections for
sUb-compact cars within an existing
lot and reiy on the location and design
of the small car parking units to attract
small cars while automatically turning
away larger cars.
Revision of parking areas requires
~
individual analysis of each parking
area. The mix of vehicle sizes must be
known and a complete layout must
confirm the gain in spaces and that
satisfactory operation is possible.
As an example of the ultimate
capaCity increase that may be
possible by parking revision, a gain of
25 percent over today's capacity
would be realized by remarking a
1,000 car lotto provide 610 sub-
compacts. and 660 regular spaces, a
total of 1,270 spaces, This would
assume that sub-compacts would
reach about 50 percent of parking
demand and that downsizing of larger
than compact size cars had been
completed,
~~
. ":' 1 ~
Strickland (F) is
engineer of traffic
planning and de-
sign tor the Traffic
Engineering Divi-
sion of the Port Au-
thority of New York
and New Jersey.
His previOUS experi-
ence includes acci-
dent analysis and reconstruction for at-
torneys. He received his B.S. in
transportation engineering from the Unjver.
sUy of Michigan and has a certificate from
the Yale Bureau of Highway Traffic. He is a
registered prOfessional engineer in New
Jersey.
~
I-~
~o' ~~"'~
-'
~..~
- I Be Part of the Transportation Revolution.
Come to Boston for ITE's 51st Annual Meeting.
,~J
,
1
1
Sheraton-Boston
Boston, Massachusells
:\uguSt 16.20, ]981
InSlirure of Transponalion Engineers
E-3
- i
.
".1
'zj
~
':::2
'! .
,
Now is Not the Time
~educp P;lrldr,g Dim.ens.ions
By James M. Hunnicutt
-
;,..,
~_'U\
<If:."'=t
_.
, 4...,_-', ~~ ..~
-~-... ,. -. 7~
- ..;,;;, ~~-';;". ,,--~> ~-' ,
.,.. . -~ .'. -;."-1''''::;':'. . _. .
:!n ~.. . ~ - -,' '''.. :~.~ :=:; ~ ~ _. 4"",.:.... _ _ _ _ - ,
""::l'I, -'~.".,.,~" ._ ""' , _
-,~ . - .:.-!;
, -<'-~'" JII~"""""""" _" _ ~ _, _<. , ,_ '.'
--'~~ -:~~;'~'1>'.4
~ .'.- . -,' . - . , '- -'- -':::::-11JeJ,JL. I ~....
- '.. ~- "':..,~",~'$;':' ~~~~'-"::,, r ~ ~= ~.di'" ,.i ~~.~~~",..:;
. ~, -- . '.' ~ e;.,;o. .-
';iiF> :)0_ ;'~~-"," "'-~'l'", ~. _' . ~~~.d.-~OS'~' , ~
~ ~.~ - ,.....,,-,.
. - --- -.... ~. -. __-- ,<it#":
.L -..' . "-- --.;,.z.... ""-~...Iiiii::t!! . , ,....- .
." --;~... . ;'-- - ~~---_...._. . .~~ .
~x._':;"'J '_;.. :e,"'_.o:~'.~"'-<.,=, ,,~~~,~
Mr. Strickland's article
primarily has to do with
parking design for smaller
cars, This type of design concept has
been around for a number ot years
and I cannot argue with the desire to
save parking area to increase
capacity, There is no doubt that cars
are getting smaller but not really
enough to justify any major redesign
of parking facilities such as re-Iaying
out of lots.
I have been against trying to set
aside certain areas for small cars, This
type of an approach may have
credence if the parkers can be well
controlled, An example of this would
be assigned spaces in an office
building garage, apartment houses or
possibly commuter parking, Some
central city locations where most
parkers stay all day can have some
dimensions reduced but a 5 percent to
7 percent reduction would be
substantial. However, I disagree with
the philosophy of laying it out for the
general public for areas such as
downtown commercial lots and
garages. Shopping center lots and
similar areas where sporadic public
parkers cannot be controlled. The
reasons I disagree with the conclusion
of the paper are as follows:
1, Lack of control. Commercial lots
and garages have experimented for
years to set aside spaces for "small
car parking", It has been found that
regardless of how hard they try, large
cars park in these spaces and as a
result block the aisles and take up two
parallel spaces, The management is
forced to regulate it by finding the
driver and sCoiding him for parking in
the wrong area, This can lose
customers and create ill will. The
customer often claims that he did not
E-4
see the signs, he was in a hurry or the
whole thing seemed silly in the first
place,
Another problem of commercial lots
and garages is to give a price
reduction for smaller cars. There is no
way for automatic parking equipment
now being used to discriminate
between small and large cars. Loop
and treadle detectors, ticket issue
machines and gates treat all cars
equally and it wouid be impOSSible to
detennine different parking charges
based on vehicle size,
2. Small car ownerShip. The
percentage of small cars in the United
States is growing but we have found
major differences around the country,
Recently we did a stUdy of cars
entering a major airport parking
garage and found that less than five
percent of them would be classified as
small cars. Yet, we know that in some
ITE Journal/Noyember 1980 , 9
"
~reas of California as high as forty
percent of the cars are classified as
,small cars, In certain parts of the
country, small cars are more popular
than in others. In upstate New York in
the Buffalo area and in Birmingham.
Alabama, we have found that large
cars make up almost ninety percent of
the average parkers in surveyed
garages, At the San Antonio Airport,
twenty percent of cars in the short
,erm lot are classified as small while
twenty-four percent of those in the
long-term lot are small cars. A
problem of a different kind is that in
Denver and Seattle as high as five
percent of the vehicles parked are
campers. They are much larger and
cause far more problems than large
cars.
3, Lack of pUblic acceptance. It is
doubtful that one person in five
hundred could tell you the wheel base
or the overall length of his automobile,
The words subcompact. compact,
mid-size, small car, 1980's size mepn
different things to different people and
to assign an area for small cars leads
to indecision by drivers who want to
do the right thing but are confused by
terminology, Automobile advertising
terminology only makes matters worse
and it would be necessary to give
each parker a list of overall length of
automobiles so he could determine
whether he has a small car, Some stall
markings paint a line across the back
of the stall to indicate if a car is too
long. However, this requires the
average driver to get out and look to
see if he overhangs the line,
4, Energy shortage. While there is
no doubt there is an energy shortage
and it is going to get worse, polls of
the American publiC indicate that the
vast majority of the American people
do not believe there is an energy
shortage, One of the major criticisms
of the President is that he has been
unable to sell the American publiC on
the energy program, For this reason.
energy consumption in the way of
gasoline is doubtful. Some economists
believe that once Americans become
accustomed to higher prices and big
cars become more fuel efficient that
cars will grow larger, This happened
during the 1974 fuel shortage when
small cars became the rage only to go
back to iarger ones a year or so later.
5, Gasoline costs. With $1,50 a
gallon gasoline now a reality, there is
no doubt that the American publiC will
20 ITC Journal/November 1980
.
Table 1. Parking Standards--Europe (Metric Dimensions)
Stall Width
Stall Length
4.75-5.0
5.0
Bay Width
Aisle Width
General
Belgium
2.4-2,5
2.4-2.5
5,5-6,0
15,5-16,0
16,0 (90 deg,)
15.0 (60 deg.)
90 deg.
45 deg.
30 deg.
15,5-16,0
15,5
2,4 5,0
2.3 5.0
2.2 5,0
2.4-2.5 4,75-5,0
2,4 5.0
2.2' 4,0'
Barcelona 2,4 4,75
Germany 2.3-2.14 5,0-5,5
. 25% of spaces, for Spanish subcompacts, may be this size,
Source: (1) Provision. location and Design of Parking Facilities in Europe; John
Glanville; International Road Federation; 1 970,
(2) The Construction of Parking Facilities; Otto Sill; 1968,
Paris
UK
Madrid
15.5
Table 2. Parking Standards--Europe (U,S. Dimensions)
Stall Width
Aisle Width
Bay Width
Stall Length
General
Belgium
15/-7"~16'e5"
16'-5"
18'-19'-6"
50'-10"-52'-611
52'-6" (90 deg)
50'-10" (60 deg)
90 deg,
45 deg,
30 deg.
50'-10"-52'-6"
50'-'0"
7'-'0"-8'-2"
7'-10"-8'-2"
7'-10" 16'-5"
7'-6" 16'-5"
7'-3" 16'-5"
7'.' 0"-8'-2" 15'-7"-16'-5"
7'-10" 16'-5"
7'-3". 13'-1".
Barcelona 7'-10" 15'.7"
Germany 7'...6"-7'-10" 16'...5"...18'-1"
. 25% spaces, for Spanish subcompacts, may be this size,
Source: (1) Provision, Location and Design of Parking Facilities in Europe; John
Glanville; International Road Federation; 1970,
(2) The Construction of Parking Facilities; Otto Sill; 1968,
Paris
UK
Madrid
50'-10"
increasingly opt for smaller cars. But,
they are more interested in gas
economy than smaller size, Auto sales
at this time indicate a 40 percent
increase in smaller cars or those
getting better gas mileage, But, it is
going to be ten to fiffeen years at this
rate before the fleet mix will permit a
smaller designed parking area and
particularly garages where the overall
parking dimensions can be changed
once it is set in concrete.
For a number of years, parking
people have tried to get more space
out of lots and garages by trying to
layout for small cars but with little
success, Headaches caused by
operation and management problems
have overshadowed any benefits that
might have been received by a few
extra spaces. This does not preclude
small spaces set aside where parking
can be controlled such as assigned
spaces. At this point, I would not
recommend to any of my clients to
build small size garages or to build
special areas for small cars.
Hunnicutt (F) is
president of James
Madison Hunnicutt
& Associates. He
has been worked in
parking and trans-.
portalion consulting
for the past 27
years and his firm
has undertaken
projects in more than 30 different states
and foreign countries. He is a graduate in
civil engineering from AUburn University
and a graduate of the Yale University BU'"
reau of Highway Traffic. He is the author of
the parking chapter of the Transportation
and Traffic Engineers Handbook and is
currently re-writing the information for the
revised handbook now in preparation. In
1976. the Institutional and Municipal Park-
ing Congress voted Mr. Hunnicutt Man of
the Year in the parking industry.
i
i
I~
E-5