HomeMy WebLinkAboutEx12_Transportation_Generation_Memorandum
12131 113th Avenue NE, Suite 203, Kirkland, WA 98034 | 425.821.3665 |
MEMORANDUM
Date: September 10, 2025 TG:1.25327.00
To: Steve Roos, HCMP
From: Dan McKinney, Jr. and Kassi Leingang, PE – Transpo Group
Subject: 601 S Grady Way – Change in Use Trip Generation Review
This memorandum summarizes the trip generation estimate completed for the proposed change of
use to a Fun Box from the existing Rite Aid located at 601 S Grady Way in the shopping center in
Renton. The project description and trip generation analysis are provided. The estimated trip
generation for the proposed development falls below the City’s traffic impact analysis 20 peak hour
trip threshold; therefore, no additional analysis is required.
Project Description
The proposed project is a change in use of the existing Rite Aid totaling 20,0001 square feet (sf)
located at 601 S Grady Way in the shopping center to the proposed Fun Box. Fun Box is an
inflatable space for kids to play and jump in as well as includes space for party rooms. The
operating hours begin at 9am, outside of the AM peak period (7-9am).
Trip Generation
Trip generation for the proposed project and existing uses to be removed were calculated based
on trip rates using the Institute of Transportation Engineers (ITE) Trip Generation Manual (12th
Edition, 2025). The trip generation estimates for the proposed use and existing uses as well as the
estimated net new trip generation for the proposed change in use are summarized below.
Note that given the operating hours being after the AM peak period, the proposed change in use
would result in a reduction in trip generation during the AM peak period and the trip generation
estimates below are focused on the PM peak period.
Proposed Use
The proposed use could be categorized as either Shopping Center or as a more specific use like
Trampoline Park. The more specific ITE use of Trampoline Park (LU 436) land use was assumed
for the proposed use given its similar attributes to the proposed use and it would be consistent
with how we evaluate the existing use in the next section. The Trampoline Park land use
description is below:
A trampoline park is a recreational facility that houses wall-to-wall trampolines and other
facilities, such as climbing walls, gymnastics tumble tracks, inflatable basketball, dodgeball
facilities, foam pits, and warrior courses. A trampoline park may also include a small on-site
cafe. It may also offer other entertainment opportunities or special events for individuals or
groups of children or adults.
Based on ITE, the project totaling 20,000 sf would be estimated to generate 30 weekday PM peak
hour trips.
1 Consistent with King County Parcel Viewer.
EXHIBIT 12
RECEIVED04/22/2026MKerrihard
PLANNING DIVISIONDocusign Envelope ID: 829F9951-CF2A-8CD2-813D-E44836C630DC
2
Existing Use
ITE land uses for the existing Rite Aid to be replaced was reviewed as either shopping center (LU
821) given its location within the larger shopping center as well as a Drug store without drive-
through (LU 880). Both land uses were estimated including reductions for pass-by which reflect
traffic already on streets in the vicinity of the project site that would visit the commercial
components of the project while driving by the site on the way to its final destination. Pass-by rates
were based on ITE Trip Generation Manual (12th Edition, 2025) for each land use.
The estimates showed that the existing use is estimated to generate 104 primary trips or 80
primary trips during the PM peak hour if assumed as a shopping center or drug store, respectively.
For purposes of estimating the net new trips associated with the change in use, the lower trip
generation for the existing use assuming a drug store was used for the analysis in order to provide
a conservative trip generation estimate. The detailed trip generation estimates of each land use for
the existing use are included in Attachment A.
Net New Trip Generation
The resulting net new trip generation for the project is summarized in Table 1 below. The detailed
trip generation calculations are included in Attachment A.
Table 1. Estimated Net New Weekday PM Peak Hour Vehicle Trip Generation
Size
PM Peak Hour
Land Use1 In Out Total
Proposed
Trampoline Park (LU 436) 20,000 sf 14 16 30
Existing
Drug Store without Drive-Through (LU 880) 20,000 sf 38 42 80
Net New Total - -24 -26 -50
Note: sf = square feet
1. Average trip rates from ITE Trip Generation Manual, 12th Edition (2025).
As shown in Table 1, the proposed change in use is estimated to result in a reduction in weekday
PM peak hour trips.
Note that the existing space as either a drug store or retail shopping center is estimated to
generate between 43 and 61 primary trips during the AM peak hour (see Attachment A for detailed
trip generation estimates). Given the proposed use is not operating during that time period, this
confirms the proposed project would result in a reduction in trip generation during the AM peak
hour, consistent with the PM peak hour.
Conclusions
The estimated weekday AM and PM peak hour trip generation for the addition per ITE falls below
the City’s 20 peak hour trip threshold identified in the Traffic Impact Analysis Policy Guidelines for
New Development and no additional traffic analysis is required for the proposed development.
Additionally, given the anticipated reduction in weekday PM peak hour trips, the traffic impact fee
for the project’s proposed change in use is $0.
Docusign Envelope ID: 829F9951-CF2A-8CD2-813D-E44836C630DC
Attachment A: Detailed Trip Generation
Docusign Envelope ID: 829F9951-CF2A-8CD2-813D-E44836C630DC
Land Use Setting Size Units Model Equation Rate Inbound % Inbound Outbound Subtotal % In Out Total Inbound Outbound Total
20,000 sf
PM Peak Hour Rate -1.50 48%14 16 30 ---14 16 30
Land Use Size Units Model Equation Rate Inbound % Inbound Outbound Subtotal % In Out Total Inbound Outbound Total
20,000 sf
Daily General Urban/Suburban Rate -90.08 50%901 901 1,802 53%478 478 956 423 423 846
AM Peak Hour General Urban/Suburban Equation (lin)T = 10.22(X) - 75.70 -65%84 45 129 53%34 34 68 50 11 61
PM Peak Hour General Urban/Suburban Rate -8.51 49%83 87 170 53%45 45 90 38 42 80
Daily -423 -423 -846
AM Peak Hour -50 -11 -61
PM Peak Hour -24 -26 -50
Primary Trips
Pharmacy/Drugstore without Drive-Through Window (880)
Gross Trips
Gross Trips
Pass-By Trips
Pass-By Trips
Fun Box - Renton
Proposed Use
Existing Use
Net New Trips
Primary Trips
Trampoline Park (436)
Notes:
1. Trip rates based on Institute of Transportation Engineers' (ITE) Trip Generation Manual (12th Edition) equation and average trip rates as shown above.
Docusign Envelope ID: 829F9951-CF2A-8CD2-813D-E44836C630DC
Land Use Size Units Model Equation Rate Units Inbound % Inbound Outbound Subtotal % In Out Total Inbound Outbound Total
20,000 sf
Daily General Urban/Suburban Rate - 90.08 per ksf 50% 901 901 1,802 53% 478 478 956 423 423 846
AM Peak Hour General Urban/Suburban Equation (lin) T = 10.22(X) - 75.70 - - 65% 84 45 129 53% 34 34 68 50 11 61
PM Peak Hour General Urban/Suburban Rate - 8.51 per ksf 49% 83 87 170 53% 45 45 90 38 42 80
20,000 sf
Daily General Urban/Suburban Rate - 101.43 50% 1,014 1,014 2,028 40% 406 406 812 608 608 1,216
AM Peak Hour General Urban/Suburban Rate - 3.54 per ksf 60% 43 28 71 40% 14 14 28 29 14 43
PM Peak Hour General Urban/Suburban Rate - 8.58 per ksf 49% 84 88 172 40% 34 34 68 50 54 104
Retail Shopping Center (821)
Pharmacy/Drugstore without Drive-Through Window (880)
Existing Use - Comparison
Gross Trips Pass-By Trips Primary Trips
Docusign Envelope ID: 829F9951-CF2A-8CD2-813D-E44836C630DC