HomeMy WebLinkAboutTraffic Study - Trip Generation Memo -1011 E Main Ave Suite 453 | Puyallup, WA | 98372
(253) 770-1401| heathtraffic.com
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TRIP GENERATION ASSESSMENT
WEST AFRICAN COMMUNITY CENTER
Renton, Washington
October 25, 2024
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West African Community Center - Trip Generation Assessment
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WEST AFRICAN COMMUNITY CENTER
TRIP GENERATION ASSESSMENT
1. INTRODUCTION
Heath & Associates has been retained to provide the City of Renton with a trip
generation assessment for the proposed change in use of an existing building at 505
S 4th Street, Renton, Washington. Below summarizes the general project narrative
and estimated trip generation.
2. PROJECT DESCRIPTION
The West African Community Center (WACC) is a proposed remodel to an existing
building located at 505 S 4th Street, Renton. The site covers .34 acres on tax parcel:
7839800145. Previously, the building was occupied by Iris—a blinds/window covering
installer with associated retail and warehouse space.
The WACC currently has around 45-50 members and plans to remodel the ~15ksf
1existing building for various uses, including a small African retail store, a community
gathering room for Friday evening board meetings, office space, and other support
areas for community activities. Site ingress/egress is to remain via two existing
driveways on S 4th Street, one to the east of the building and one to the west.
Figure 1 on the following page displays the vicinity map with the subject parcel
highlighted in blue. Figure 2 illustrates the conceptual floor plan with the various
spaces.
1 Per King County’s GIS Assessor, the building’s gross square foot is listed as 14,998 sq. ft.
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Figure 1: Vicinity Map
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Subject Site
S 4th Street
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Figure 2: Conceptual Site Plan
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3. TRIP GENERATION
Project Trip Generation
Trip generation estimates were derived from the expected use of the site. Trip
generation for the previous use was also estimated and will be taken for credit
against the proposed uses. For the West African Community Center, some uses will
occur daily. The site is expected have a small (3,028 square foot) retail space, a
gathering area (marked Lobby/Open Space on the conceptual site plan), some office
space, and a library. There will also be a group tutorial room, where a variety of
tutoring services will take place. The gathering area will be used infrequently (e.g.,
the gathering area is for Friday evening board meetings twice per month).
Proposed Uses: Retail, Office, Group Tutoring, and Gathering Area
Retail Space: The retail space will be occupied by a specialty retail shop that sells
food products, clothing, and other items from West African cultures. Transaction data
from the existing West African retail store that is proposed to relocate to this site was
reviewed (Gambia International, 5903 Rainier Avenue S, Seattle). Data from 15
midweek, midsummer weekdays were reviewed. These data show an average of 39
transactions per day. Assuming 2.2 trips per transaction, this results in 86 daily trips1.
Since the transactions are not time-stamped, it is assumed that 5% of these trips are
made during the AM peak hour (4 trips), and 8% of these trips are made during the
PM peak hour (7 trips)2.
Group Tutorial: The site will host group tutoring during weekdays. Tutoring sessions
will begin at 1:30 and 3:30, and last one to two hours. About 10 people per session,
or 20 per day, may be tutored at the site, with two tutors assisting them. This use
would result in an estimated 28 daily trips. This assumes some carpooling for
students, as the tutoring session students are from the local West African community.
No AM peak hour trips are expected for the tutoring; all tutoring takes place in the
afternoon. With the second afternoon session beginning at 3:30, it is estimated that
there will be 12 student vehicle trips (2 entering, 10 exiting) during the pm peak hour,
as well as two tutor vehicle trips leaving the site.
1 This allows for shoppers, employee trips, and deliveries.
2 Information from the Institute of Transportation Engineers’ Trip Generation, Time of Day Vehicle Distribution for
Land Use Code 822 (Strip Retail Plaza) indicates 8% of the daily trips occur during the PM peak hour for this land
use.
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Office Space: The site will include about 2,725 square feet of office space and a
library. Some office space is for use by the Board president and one or two
employees/volunteers. There are other small office spaces for counseling. Trip
generation for office space was based on the Institute of Transportation Engineers
Trip Generation Manual, 11th Edition, under LUC 712 – Small Office. Per thousand
square feet was used for the variable, and average rates were applied. This results in
an estimate daily trip generation of 39 trips, with 9 AM peak hour trips and 6 PM peak
hour trips.
Gathering Area: The open space between the offices and the retail space on the first
floor would be used for bimonthly board meetings. Those meetings might host
between 50 and 60 people and would occur every other Friday evening. Therefore,
there is no expected, regular midweek trip generation associated with this use.
Part of the building will be used to store various items for the local West African
Community, for use in celebrations and for other activities. This space is not expected
to generate regular daily or peak hour trips.
Previous Use: Specialty Contractor – Blinds/Window Covering Store/Warehouse
The previous site user utilized the full building, at about 15 ksf. In review of the Trip
Generation Manual, LUC 180 – Specialty Trade Contractor was deemed most
comparable to the previous tenant—a blinds/window covering installer with
associated retail and warehouse space. Square footage and average rates were again
applied. The daily trip generation for the prior use is estimated at 147 daily trips, with
25 trips (18 entering, 7 exiting) expected during the AM peak hour and 29 trips (9
entering, 20 exiting) during the PM peak hour. These trips are taken as credits in the
trip generation table on the following page.
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Table 1: Project Trip Generation
Land Use Size AWDT AM Peak-Hour Trips PM Peak-Hour Trips
In Out Total In Out Total
Proposed Uses:
Retail 3.03 ksf 86 3 1 4 1 6 7
Group Tutorial 1.2 ksf 28 0 0 0 2 12 14
Small Office 2.73 ksf 39 4 1 5 2 4 6
Total Proposed Use Trips 153 7 2 9 4 22 27
Previous Use:
Specialty
Contractor
15 ksf -147 -18 -7 -25 -9 -20 -29
Net New Site Trips +6 -11 -4 -17 -4 +2 -2
Based on the change in use, and the operating characteristics of the WACC, a slight
reduction in PM peak hour trips is estimated.
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CONCLUSION
The trip generation assessment for the West African Community Center (WACC) at
505 S 4th Street indicates that the proposed uses, including a retail space, group
tutorial area, office spaces, and a gathering room, will collectively generate fewer
weekday PM peak hour trips than the previous use as a specialty contractor. As a
result, no further analysis is identified at this time, and no Traffic Impact Fees (TIF)
would be assessed.
Please feel free to contact me should you require further information.
Respectfully,
Aaron Van Aken, PE, PTOE
avanaken@heathtraffic.com
(253) 770-1401
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WEST AFRICAN COMMUNITY CENTER
TRIP GENERATION ASSESSMENT
APPENDIX
ITE Trip Generation Data – Specialty Contractor LUC 180
& Small Office LUC 712
11/22/21, 9:54 AM https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=AWDVTE&x=&edition=639&locationCode=General…
https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=AWDVTE&x=&edition=639&locationCode=General Urban/Suburban&co…1/1
Specialty Trade Contractor
(180)
Vehicle Trip Ends vs:1000 Sq. Ft. GFA
On a:Weekday
Setting/Location:General Urban/Suburban
Number of Studies:20
Avg. 1000 Sq. Ft. GFA:6
Directional Distribution:50% entering, 50% exiting
Vehicle Trip Generation per 1000 Sq. Ft. GFA
Average Rate Range of Rates Standard Deviation
9.82 3.00 - 43.33 8.56
Data Plot and Equation
T
=
T
ri
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X = 1000 Sq. Ft. GFA
Study Site Average Rate
Fitted Curve Equation: Not Given R²= ****
Trip Gen Manual,11th Edition Institute of Transportation Engineers
0 5 10 15 200
100
200
300
11/22/21, 9:55 AM https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=TASIDE&x=&edition=639&locationCode=General …
https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=TASIDE&x=&edition=639&locationCode=General Urban/Suburban&cou…1/1
Specialty Trade Contractor
(180)
Vehicle Trip Ends vs:1000 Sq. Ft. GFA
On a:Weekday,
Peak Hour of Adjacent Street Traffic,
One Hour Between 7 and 9 a.m.
Setting/Location:General Urban/Suburban
Number of Studies:20
Avg. 1000 Sq. Ft. GFA:6
Directional Distribution:74% entering, 26% exiting
Vehicle Trip Generation per 1000 Sq. Ft. GFA
Average Rate Range of Rates Standard Deviation
1.66 0.12 - 9.17 2.00
Data Plot and Equation
T
=
T
ri
p
E
n
d
s
X = 1000 Sq. Ft. GFA
Study Site Average Rate
Fitted Curve Equation: Not Given R²= ****
Trip Gen Manual,11th Edition Institute of Transportation Engineers
0 5 10 15 200
10
20
30
40
11/22/21, 9:55 AM https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=TPSIDE&x=&edition=639&locationCode=General …
https://itetripgen.org/PrintGraph.htm?code=180&ivlabel=QFQAF&timeperiod=TPSIDE&x=&edition=639&locationCode=General Urban/Suburban&cou…1/1
Specialty Trade Contractor
(180)
Vehicle Trip Ends vs:1000 Sq. Ft. GFA
On a:Weekday,
Peak Hour of Adjacent Street Traffic,
One Hour Between 4 and 6 p.m.
Setting/Location:General Urban/Suburban
Number of Studies:19
Avg. 1000 Sq. Ft. GFA:6
Directional Distribution:32% entering, 68% exiting
Vehicle Trip Generation per 1000 Sq. Ft. GFA
Average Rate Range of Rates Standard Deviation
1.93 0.38 - 10.83 1.98
Data Plot and Equation
T
=
T
ri
p
E
n
d
s
X = 1000 Sq. Ft. GFA
Study Site Average Rate
Fitted Curve Equation: Not Given R²= ****
Trip Gen Manual,11th Edition Institute of Transportation Engineers
0 5 10 15 200
10
20
30
40
50
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WEST AFRICAN COMMUNITY CENTER
TRIP GENERATION ASSESSMENT
APPENDIX
Full Site Plan
Scale
Project number
Date
Drawn by
Checked by
1" = 20'-0"
10
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2
4
9
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1
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P
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A100
EXISTING SITE PLAN
Project Number
PROPOSED
-
10/02/24
FB
FB
No. Description Date
1" = 20'-0"1 survey
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,
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UP
WC
WC
KITCHEN
OFFICE
MEZANNINE ABOVE
OPEN OFFICE
WC
WHAREHOUSE
WHAREHOUSE
STORAGE RM
ATTICATTIC
ROOM
MEZANINEOPEN TO BELOW
OPEN TO BELOW
FURNACE FURNACE
STORAGE
Scale
Project number
Date
Drawn by
Checked by
1/8" = 1'-0"
10
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2
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9
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P
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A101
BUILDING LAYOUT
Project Number
PROPOSED
-
10/02/24
fb
fb
No. Description Date
50
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Architect: Fatah Boualamallah
Address: 5333 150th PL SW Edmonds,
WA 98026
Phone: 425-268-3883
e-mail: fbarchitects@frontier.com
1/8" = 1'-0"1 EXISTING FIRST FLOOR
1/8" = 1'-0"2 EXISTING SECOND FLOOR
N N
DW
Range
Refrigerator
UP
148 SF
Stair
8
1167 SF
Group Tutorial
11
1039 SF
Retail Storage
14
3028 SF
Retail Store
15
Women
23
163 SF
Mechanical
13
WC
Men's
28
362 SF
Office 1
29
Break
Room/Kitchen
31
567 SF
Hallway
32
Utility
33
Mop
34
342 SF
Board Office
9
1042 SF
Community
Storage
20
1445 SF
Lobby/Open
Space
36
706 SF
Library
37
Open to Attic Open to Attic
Open to Attic
244 SF
CounselingOffice
35
266 SF
Counseling office
39
290 SF
Counseling Office
40
276 SF
Counseling offfice
41
Room
42
470 SF
Attic Storage
43
Men
44
Women
45
Bathroom
46
239 SF
Retail /Office
3
265 SF
Hallway
48
919 SF
Storage
5
Scale
Project number
Date
Drawn by
Checked by
1/8" = 1'-0"
10
/
2
/
2
0
2
4
9
:
0
1
:
2
0
P
M
A102
BUILDING
LAYOUT/PROGRAM
Project Number
PROPOSED
-
10/02/24
fb
fb
No. Description Date
Architect: Fatah Boualamallah
Address: 5333 150th PL SW Edmonds,
WA 98026
Phone: 425-268-3883
e-mail: fbarchitects@frontier.com
50
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1/8" = 1'-0"1 PROPOSED FIRST FLOOR
1/8" = 1'-0"2 PROPOSED SECOND FLOOR
N N
PRELIMINARY PLANS-NOT FOR CONSTRUCTION