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2813 Rockefeller Avenue Suite B Everett, WA 98201
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MEMORANDUM
To: Jonathan Chavez, PE, City of Renton
From: Brad Lincoln, PE
Project: 600 SW 10th Avenue Parking Expansion
LUA21-000273
Subject: Traffic Analysis
Date: November 19, 2021
GTC #: 21-375
This memorandum summarizes the traffic analysis for the parking lot expansion for the building
located at 600 SW 10th Street in the City of Renton. A site vicinity map in included in Figure 1.
Figure 1: Site Vicinity
Lind Ave SW SW 7th St Thomas Ave SW SITE Rainier Ave S RECEIVED
12/13/2021
AMorganroth
PLANNING DIVISION
DocuSign Envelope ID: 3CB3A7A8-E3D0-4C56-A6E9-3567A8E14069
600 SW 10th Street Parking Expansion Traffic Analysis
Gibson Traffic Consultants, Inc. November 2011
info@gibsontraffic.com 2 GTC #21-375
The SW 10th Street Parking Expansion is proposing to pave the existing gravel areas to facilitate better
storage of materials and parking of vehicles. The parking expansion is not proposed to change the use
of the building, the number of accesses, or the location of the accesses.
The trip generation of the building located at SW 10th Street has been calculated based on data
contained in the Institute of Transportation Engineers’ (ITE) Trip Generation Manual, 10th Edition
(2017) and information on the actual use of the site. The average trip generation rates for ITE Land
Use Code 140, Manufacturing, has been used for the trip generation calculations since the existing
use is primarily manufacturing, meaning raw materials and components are turned into some type of
product. The trip generation of the existing 114,531 SF building using ITE average trip generation
rates is summarized in Table 1.
Table 1: Trip Generation Summary – ITE Data
114,531 SF
Manufacturing
Average Daily Trips AM Peak-Hour Trips PM Peak-Hour Trips
Inbound Outbound Total Inbound Outbound Total Inbound Outbound Total
Generation Rate 3.93 trips per 1,000 SF 0.62 trips per 1,000 SF 0.67 trips per 1,000 SF
Splits 50% 50% 100% 77% 23% 100% 31% 69% 100%
Trips 225 225 450 55 16 71 24 53 77
The trip generation calculations have also been performed base on the existing use of the site,
including the number of employees, shift schedule, and schedules for deliveries to the site and from
the site. The existing use includes the following:
40 employees
2.5 shifts per day
25 deliveries per day (total of deliveries to the site and from the site)
5 rail deliveries per week, equal to 20 truck deliveries per week
These uses are approximate since some days there may be 20 total deliveries and other days may have
30 total deliveries. These numbers are meant to represent the average day. The trip generation of the
current use of the existing building is summarized in Table 2.
Table 2: Trip Generation Summary – Current Use
Generator Quantity
Trips
Assumptions Daily Peak-Hour
Employees
(40 employees with 2.5 shifts) 100 300 80 3 daily trips per employee
shift change during peak-hour
Deliveries
(to the site and from the site) 25 50 5 2 daily trips per employee
10% during peak-hour
Deliveries
(rail equivalent) 5 10 0 Rail deliveries become truck deliveries
TOTAL --- 360 85
DocuSign Envelope ID: 3CB3A7A8-E3D0-4C56-A6E9-3567A8E14069
600 SW 10th Street Parking Expansion Traffic Analysis
Gibson Traffic Consultants, Inc. November 2011
info@gibsontraffic.com 3 GTC #21-375
The trip generation based on the ITE data and the current use are very similar. It is important to note
that the peak-hour trip generation of the current use assumed there is a shift change during the peak-
hour. A shift change occurs outside the peak-hour would significantly reduce the peak-hour trip
generation of the current use.
The current use is not anticipated to change with the proposed parking lot expansion. The only change
would be that materials and trucks would be stored on a paved surface, as opposed to a gravel surface.
The traffic impacts of the building at 600 SW 10th Street are therefore not proposed to change with
the proposed paving. It is possible that a future use could utilize the site and change the trip generation.
However, the traffic impacts of any future potential use should be evaluated when an application,
such as a tenant improvement, is applied for. The proposed parking expansion should be approved
with regards to traffic impacts without further analysis and without the need for traffic mitigation
fees.
DocuSign Envelope ID: 3CB3A7A8-E3D0-4C56-A6E9-3567A8E14069