22-104290-AG Updated Traffic Memo 8-1-23
12131 113th Avenue NE, Suite 203, Kirkland, WA 98034 | 425.821.3665 |
MEMORANDUM
Date: July 26, 2023 TG:1.22327.00
To: Keith Niven, Community Development Director, City of Federal Way
Rick Perez, City Traffic Engineer, City of Federal Way
From: Dan McKinney Jr. and Stefanie Herzstein, PE
cc: Ann Gygi, Hillis Clark Martin & Peterson P.S.
Subject: Enchanted Parks Concomitant Agreement Amendment – Response to Public
Works Traffic Comments
The following memo responds to technical review comments from the City of Federal Way Public
Works Traffic Division in a letter to Ann Gygi dated June 2, 2023. This specifically responds to
comments 3 and 4, which are as follows:
3) Need professional trip generation information that addresses having multiple uses on the
property at the same time, such as regional commercial recreation facility and warehousing.
4)Trip generation for any new proposal would be based on ITE trip generation manual 8th edition
(2002-2003).
In response to these comments, updated trip generation calculations are provided below using the
ITE trip generation manual 8th Edition. Trip generation was calculated for a few scenarios to
illustrate the volume of traffic that could be generated by other uses being proposed as part of the
updated Concomitant Development Agreement (CDA).
This section outlines trip generation associated with alternative land uses that are proposed as
part of the revised CDA. Calculations and comparison of trip generation associated with Hotel,
Warehousing, Resort Hotel, and mix of Hotel and Warehousing land uses are provided. It is not
anticipated that this facility would be able to exist with another land use; however, a scenario
assuming half of the facility remains, and half of another use is proposed is provided below.
Weekday Daily, AM and PM peak hour trip generation are estimated based on the land use size
and trip rates from the Institute of Transportation Engineers’ (ITE) Trip Generation Manual, 8th
Edition for Hotel (LU 310), Resort Hotel (LU 330) and for Warehousing (LU150).
All Hotel Land Use
The Hotel land use was assumed to include 450 rooms as summarized in the Table 1 below.
Table 1. Estimated Weekday Vehicle Trip Generation - Hotel (LU 310)
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Hotel
(LU 310) 450 rooms 8.17 trips per room 3,676 0.56 trips per room 252 0.59 trips per room 266
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, a 450-room hotel would generate 266 PM peak hour trips during a typical weekday.
This hotel trip generation is 147 PM peak hour trips less than the 413 average day PM peak hour
trips approved in the current CDA.
2
All Resort Hotel Land Use
The Resort Hotel land use was assumed to include 450 rooms as summarized in the Table 2.
Table 2. Estimated Weekday Vehicle Trip Generation - Resort Hotel (LU 330)
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Resort Hotel
(LU 330) 450 rooms 5.82 trips per room 2,620 0.31 trips per room 140 0.42 trips per room 189
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, a 450-room resort hotel would generate 189 PM peak hour trips during a typical
weekday. This resort hotel trip generation is 224 PM peak hour trips less than the 413 average
day PM peak hour trips approved in the current CDA.
All Warehouse Land Use
The Warehousing land use was assumed to include 1,000,000 square-feet (sf) as summarized in
the Table 3.
Table 3. Estimated Weekday Vehicle Trip Generation - Warehouse (LU 150)
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Warehousing
(LU 150) 1,000,000 sf 3.56 per 1,000 sf 3,560 0.30 per 1,000 sf 300 0.32 per 1,000 sf 320
Note: sf = square-feet
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, a 1,000,000 sf warehouse would generate 320 PM peak hour trips during a typical
weekday. This warehousing trip generation is 93 PM peak hour trips less than the 413 average
day PM peak hour approved in the current CDA.
Mixed Warehouse and Hotel Land Use
The Warehousing and Hotel land uses were assumed to include half of the full development level
with 500,000 sf of warehousing and 225 hotel rooms as summarized in the Table 4.
Table 4. Estimated Weekday Vehicle Trip Generation - Warehouse (LU 150) and Hotel (LU 310)
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Warehousing
(LU 150) 500,000 sf 3.56 per 1,000 sf 1,780 0.30 per 1,000 sf 150 0.32 per 1,000 sf 160
Hotel
(LU 310) 225 rooms 8.17 trips per room 1,838 0.56 trips per room 126 0.59 trips per room 133
Net Total
Vehicle Trips - - 3,618 - 276 - 293
Note: sf = square-feet
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, the mixed usage of hotel and warehouse would generate 293 PM peak hour trips
during a typical weekday. This mixed usage of hotel and warehouse vehicle trip generation is 120
PM peak hour trips less than the 413 average day PM peak hour approved in the current CDA.
3
Detailed trip generation tables for these four scenarios are provided as attachments.
The next three scenarios assume a mix of half the existing Regional Recreation Facility with either
Warehouse, Resort Hotel, or Hotel uses sharing this site. Without speaking to the feasibility of any
particular use combination, these scenarios illustrate that these combinations would also generate
less than the mitigated trip levels.
Mixed Regional Recreation Facility and Warehouse
A scenario assuming existing Regional Recreation Facility and Warehouse is provided in Table 5,
assuming half of the full development level of each.
Table 5. Estimated Weekday Vehicle Trip Generation - Warehouse (LU 150) and Regional Recreational
Facility
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Warehousing
(LU 150) 500,000 sf 3.56 per 1,000 sf 1,780 0.30 per 1,000 sf 150 0.32 per 1,000 sf 160
Regional
Recreation
Facility
Half Existing 2,294 207
Net Total
Vehicle Trips - - 4,074 - - - 367
Note: sf = square-feet
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, the mixed usage of regional recreation facility and warehouse would generate 367 PM
peak hour trips during a typical weekday, generating 46 vehicle trips less than the 413 average
day PM peak hour trips approved in the current CDA.
Mixed Regional Recreation Facility and Resort Hotel
A scenario assuming existing Regional Recreation Facility and Resort Hotel is provided in Table 6,
assuming half of the full development level of Regional Recreation Facility.
Table 6. Estimated Weekday Vehicle Trip Generation – Resort Hotel (LU 330) and Regional Recreational
Facility
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Resort Hotel
(LU 330) 450 rooms 5.82 trips per room 2,620 0.31 trips per room 140 0.42 trips per room 189
Regional
Recreation
Facility
Half Existing 2,294 207
Net Total
Vehicle Trips - - 4,914 - - - 396
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, the mixed usage of resort hotel and regional recreation facility would generate 396 PM
peak hour trips during a typical weekday, generating 17 vehicle trips less than the 413 average
day PM peak hour trips approved in the current CDA.
4
Mixed Regional Recreation Facility and Hotel
A scenario assuming existing regional recreation facility and hotel is provided in Table 7, assuming
half of the full development level of each.
Table 7. Estimated Weekday Vehicle Trip Generation - Hotel (LU 310) and Regional Recreational Facility
Land Use Size
Daily Trips AM Peak Hour Trips PM Peak Hour Trips
Trip Rate Total Trip Rate Total Trip Rate Total
Hotel
(LU 310) 225 rooms 8.17 trips per room 1,838 0.56 trips per room 126 0.59 trips per room 133
Regional
Recreation
Facility
Half Existing 2,294 207
Net Total
Vehicle Trips - - 4,132 - - - 340
1. Based on ITE Trip Generation (8th Edition, 2008)
As shown, the mixed usage of hotel and regional recreation facility would generate 340 PM peak
hour trips during a typical weekday, generating 73 vehicle trips less than the 413 average day PM
peak hour trips approved in the current CDA.
All of the scenarios above would generate less than the 413 average day PM peak hour approved
in the current CDA.
ATTACHMENT - TABLE 1 DETAIL
Land Use Setting Size Units Model Equation Rate Units Inbound % Inbound Outbound Subtotal Inbound Outbound Total
450 rooms Daily General Urban/Suburban Rate -8.17 per room 50%1,838 1,838 3,676 1,838 1,838 3,676
AM Peak Hour General Urban/Suburban Rate -0.56 per room 61%154 98 252 154 98 252
PM Peak Hour General Urban/Suburban Rate -0.59 per room 53%141 125 266 141 125 266
Subtotal
Daily 1,838 1,838 3,676 1,838 1,838 3,676
AM Peak Hour 154 98 252 154 98 252
PM Peak Hour 141 125 266 141 125 266
Daily 1838 1838 3676 AM Peak Hour 154 98 252 PM Peak Hour 141 125 266
Proposed Use
Net New Trips
Hotel (LU 310)
Gross Trips Total Net New
1. Trip rates based on Institute of Transportation Engineers' (ITE) Trip Generation 8th Edition equation and average trip rate as shown above.
Notes:
ATTACHMENT - TABLE 2 DETAIL
Land Use Setting Size Units Model Equation Rate Units Inbound % Inbound Outbound Subtotal Inbound Outbound Total
450 rooms
Daily General Urban/Suburban Rate -5.82 per room 50%1,310 1,310 2,620 1,310 1,310 2,620
AM Peak Hour General Urban/Suburban Rate -0.31 per room 72%101 39 140 101 39 140
PM Peak Hour General Urban/Suburban Rate -0.42 per room 43%81 108 189 81 108 189
Subtotal
Daily 1,310 1,310 2,620 1,310 1,310 2,620
AM Peak Hour 101 39 140 101 39 140 PM Peak Hour 81 108 189 81 108 189
Daily 1310 1310 2620 AM Peak Hour 101 39 140 PM Peak Hour 81 108 189
Gross Trips Total Net New
Proposed Use
Net New Trips
Resort Hotel (LU 330)
1. Trip rates based on Institute of Transportation Engineers' (ITE) Trip Generation 8th Edition equation and average trip rate as shown above.
Notes:
Land Use Setting Size Units Model Equation Rate Units Inbound % Inbound Outbound Subtotal Inbound Outbound Total
1,000,000 sf
Daily General Urban/Suburban Rate -3.56 per ksf 50%1,780 1,780 3,560 1,780 1,780 3,560 AM Peak Hour General Urban/Suburban Rate -0.30 per ksf 79%237 63 300 237 63 300 PM Peak Hour General Urban/Suburban Rate -0.32 per ksf 25%80 240 320 80 240 320
Subtotal
Daily 1,780 1,780 3,560 1,780 1,780 3,560
AM Peak Hour 237 63 300 237 63 300 PM Peak Hour 80 240 320 80 240 320
Daily 1780 1780 3560
AM Peak Hour 237 63 300 PM Peak Hour 80 240 320
Gross Trips Total Net New
Proposed Use
Net New Trips
Warehousing (LU 150)
ATTACHMENT - TABLE 3 DETAIL
1. Trip rates based on Institute of Transportation Engineers' (ITE) Trip Generation 8th Edition equation and average trip rate as shown above.
Notes:
ATTACHMENT - TABLE 4 DETAIL
Land Use Setting Size Units Model Equation Rate Units Inbound % Inbound Outbound Subtotal Inbound Outbound Total
500,000 sf Daily General Urban/Suburban Rate -3.56 per ksf 50%890 890 1,780 890 890 1,780
AM Peak Hour General Urban/Suburban Rate -0.30 per ksf 79%119 31 150 119 31 150
PM Peak Hour General Urban/Suburban Rate -0.32 per ksf 25%40 120 160 40 120 160
225 rooms
Daily General Urban/Suburban Rate -8.17 per room 50%919 919 1,838 919 919 1,838 AM Peak Hour General Urban/Suburban Rate -0.56 per room 61%77 49 126 77 49 126
PM Peak Hour General Urban/Suburban Rate -0.59 per room 53%70 63 133 70 63 133
Subtotal Daily 1,809 1,809 3,618 1,809 1,809 3,618
AM Peak Hour 196 80 276 196 80 276
PM Peak Hour 110 183 293 110 183 293
Daily 1809 1809 3618
AM Peak Hour 196 80 276 PM Peak Hour 110 183 293
Gross Trips Total Net New
Proposed Use
Net New Trips
Warehousing (LU 150)
Hotel (LU 310)
1. Trip rates based on Institute of Transportation Engineers' (ITE) Trip Generation 8th Edition equation and average trip rate as shown above.
Notes: