DMCBP CMP Traffic Study

8/2/2019 DMCBP CMP Traffic Study

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Appendix DTraffic Analysis Report

Des Moines Creek Business ParkConceptual Master Plan


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Contents

Page

Executive Summary........................................................................................................................D-1

D1 Introduction........................................................................................................................D-7D1.1 Alternatives Evaluated .........................................................................................D-7D1.2 Purpose and Scope ................................................................................................D-8

D2 Existing Conditions...........................................................................................................D-9D2.1 Site Conditions and Adjacent Land Uses ........................................................... D-9D2.2 Transportation Facilities ....................................................................................... D-9D2.3 Existing Volumes and Traffic Operations ........................................................ D-10

D2.3.1 Existing Traffic Volumes ......................................................................D-10D2.3.2 Existing Traffic Operations .................................................................. D-10D2.3.3 Operational Analysis Methods ............................................................D-11D2.3.4 Mobility Standards ................................................................................D-12D2.3.5 Traffic Operations.................................................................................. D-12


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APPENDIX D TRAFFIC ANALYSIS STUDY

Tables

D-1 Trip Generation Results for Preliminary Alternatives

D-2 Des Moines Creek Business Park Intersection Analysis Summary

D-3 Existing Transportation Facility CharacteristicsDes Moines Creek Business ParkStudy Area

D-4 Mobility Standards for Des Moines Creek Business Park Traffic Study

D-5 Existing p.m. Peak-Hour Intersection Levels of Service (2005)

D-6 Preliminary Alternative 1 Estimated Trip Generation

D-7 Preliminary Alternative 2 (Alternative A) Estimated Trip Generation

D-8 Preliminary Alternative 3 (Alternative B) Estimated Trip Generation

D-9 2008 p.m. Peak-Hour Intersection Analysis

D-10 2015 p.m. Peak-Hour Intersection Analysis

D-11 2008 p.m. Peak-Hour Improved Intersection Analysis

D-12 2015 p.m. Peak-Hour Improved Intersection Analysis

Figures

D-1 Vicinity Map


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Executive Summary

The Des Moines Creek Business Park (DMCBP) is a proposed mixed-use business parklocated in the City of Des Moines, Washington, south of Seattle-Tacoma (Sea-Tac)International Airport. The northern boundary of the site is adjacent to the City of SeaTacalong South 208th Street. The 89-acre site lies north of South 216th Street and west of 24thAvenue South. It is approximately 0.45 mile west of International Boulevard and 0.7 milewest of Interstate 5. The site is directly east of Des Moines Creek Park. Figure D-1 shows the

site vicinity. The site is currently owned by the Port of Seattle (the Port), except for someunused rights-of-way owned by the City of Des Moines. The existing land use is vacant.

The site will be accessed from two locations. Access from the south will occur on South216th Street, directly across from 20th Avenue South, aligning with the driveway of theCitys existing post office. Access from the east will occur via 24th Avenue South near South208th Street or South 210th Street. These two points will serve as accesses for both vehiclesand trucks.

The land is zoned Business Park (B-P) by the City of Des Moines. According to the DesMoines Municipal Code, the primary purpose of the B-P zone is to provide suitable areas ofthe city for development of compatible business, professional office, light industrial,research and development, service uses, wholesale trade, and retail uses serving the needsof business park tenants. Development of the DMCBP site is consistent with City of DesM i h i l i d t Th it i l ifi d B i P k


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APPENDIX D TRAFFIC ANALYSIS REPORT

office/research and development land uses. The three alternatives were predicted togenerate between 745 and 945 p.m. peak-hour trips at full buildout. Table D-1 provides a

summary of the trip generation for the three preliminary alternatives. (Note that tripgeneration for the site is within the parameters of future development assumed by the PugetSound Regional Council [PSRC] and therefore has already been accounted for in regionaltraffic modeling for purposes of air quality conformity.)

Because Alternative 1 represented an intermediate development condition between theother two alternatives, it was subsequently determined that only Alternatives 2 and 3(renamed A and B, respectively) would be evaluated in detail for surface transportation.These two alternatives reflect what is considered to be a reasonable range of trafficconditions for DMCBP, given Port and City objectives for the project, foreseeable marketconditions, and the physical setting of the property. Each of the development alternativesincludes approximately 1,000,000 square feet of building area at full buildout.

TABLE D-1

Trip Generation Results for Preliminary Alternatives

p.m. Peak-Hour Trip Generation

AlternativeSquareFootage

Approximate Land UseComposition

(Manufacturing/Logistics/Office)Initial Land UseDevelopment Buildout

Alternative 1 1,000,000 50% / 25% / 25% 860 860

Alternative 2 (Alt. A) 1,000,000 30% / 50% / 20% 745 745

Alternative 3 (Alt. B) 1,000,000 25% / 25% / 50% 860a

955b

a


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would result in additional delay at these intersections as compared to No Build conditions.The analysis resulted in the following findings and conclusions:

Buildout of both alternatives is expected to meet agency LOS thresholds in both 2008and 2015. However, if desired, signal optimization and International Boulevard/PacificHighway corridor progression could be used to restore intersection operations to NoBuild LOS thresholds for Alternative A and to improve operations for Alternative B.(Signal optimization is assumed in the Alternative A Improved and Alternative BImproved columns of Table D-2.) Impacts on International Boulevard in the City ofSeaTac are minimized, because northbound trips on International Boulevard occurprimarily in the p.m. peak hour. Because this is the nonpeak direction at this time, thereis available capacity to accommodate these trips without the addition of new capacity.

Buildout of Alternative B would generate greater traffic impacts than Alternative Abecause of the higher number of trips associated with the increased office space. Signaloptimization alone would not be sufficient to bring Alternative B back to No Build levelsof delay without the development of new capacity through SR 509 or a project of similarscope. To restore operations to No Build conditions, the land use mixture would need tobe altered to reduce the number of p.m. peak-hour trips to approximately 830. This

would be possible if some of the office development were replaced with manufacturingand/or logistics uses. The Alternative B Improved column in Table 2 assumesadjustment of land uses on the site to maintain a maximum of 830 p.m. peak trips.

Installation of a traffic signal is recommended at South 216th Street and 20th AvenueSouth. This signal would be interconnected with the already programmed traffic signal


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TABLE D-2

Des Moines Creek Business Park Intersection Analysis Summary

2005 2008 2015

Existing No Build Alt. A Alt. AImproved

aAlt. B Alt. B

Improveda

No Build Alt. A Alt. AImproved

aAlt. BIntersection

LOS Delay LOS Delay LOSDelay LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay

International Boulevard/S. 188th St. E 72.8 E 77.5 E 79.7 E 59.1 F 81.3 E 59.5 F 87.9 F 94.8 E 70.5 F 97.2

International Boulevard/S. 200th St. E 60.9 E 66.4 E 76.5 E 66.7 F 80.4 E 66.9 E 78.4 F 93.3 E 76.4 F 97.7

International Boulevard/S. 208th St. B 15.9 B 18.9 D 44.4 C 29.7 E 55.9 C 31.8 C 21.4 E 59.8 D 36.9 E 77.7

International Boulevard/S. 216th St. D 47.6 E 67.7 F 85.5 E 59.2 F 93.3 E 58.7 F 92.6 F 106.1 E 73.7 F 110.0

Pacific Highway South/SR 516 F 100.4 F 94.5 F 106.4 F 93.6 F 111.9 F 94.7 F 123.3 F 138.4 F 113.5 F 143.2

S. 188th Street/28th Avenue S. C 25.0 C 25.1 C 27.6 B 19.7 C 28.3 B 19.9 C 26.1 D 38.1 C 20.6 D 41.5

S. 200th Street/26th Avenue S. A 9.3 A 9.3 A 9.6 A 9.6 A 9.6 A 9.6 A 9.5 A 9.8 A 9.8 A 9.8

S. 208th Street/24th Avenue S. B 10.8 B 11.1 B 14.4 B 14.4 C 15.6 B 14.8 B 11.3 B 14.5 B 14.5 C 15.8

S. 216th Street/24th Avenue S. F >150 A 8.0 B 17.4 C 21.2 C 26.0 C 24.3 A 8.4 B 18.5 C 20.9 C 27.7

S. 188th Street/Des MoinesMemorial Dr.

D 37.0 D 44.5 D 46.6 D 46.6 D 46.8 D 46.5 E 64.9 E 67.1 D 48.3 E 67.3

S. 216th Street/Military Road S. C 33.3 C 34.3 D 37.7 D 37.7 D 38.7 D 38.1 D 37.7 D 46.5 D 46.5 D 48.1

aImprovements for Alternative A include signal timing optimization and coordination. Improvements for Alternative B include either revising the land use mixture or a redu

100,000 square feet of office space to reduce the number of vehicles on the roadway system with signal timing optimization and coordination.

Notes:

Intersection conditions highlighted in bold and shaded text indicate unacceptable LOS based on the Cities of SeaTac and Des Moines standards. Refer to Table D-4 for thTable D-4 for applicable LOS standards.Underlined results indicate an unsignalized intersection.


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S. 208th St.

S. 188th St.

esMem

orial

Driv

e

.

I n t e

r n a

t i o n a

l B o

u l e

v a r d

S. 200th St.

28th/24th

Ave.

S.

Angle Lake

Future Detention Pond

Christian Faith Center

Alaska Airlines

Sea-Tac International Airport

DesMoinesCr

eek

P

U

G

E

T

S

O

U

N

D


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CHAPTER D1

Introduction

The proposed DMCBP site is located in the City of Des Moines, Washington, south ofSea-Tac Airport. The northern boundary of the site is adjacent to the City of SeaTac. The 89-acre site lies north of South 216th Street and west of 24th Avenue South. Currently, the siteis vacant. The Des Moines Comprehensive Plan identifies future business park development

at this location, consistent with the intent of the proposed DMCBP. Figure D-1 shows theproject vicinity.

The site will be accessed from two locations. Access from the south will occur on South216th Street, directly across from 20th Avenue South, aligning with the driveway of theCitys existing post office. Access from the east will occur via 24th Avenue South near South208th Street or South 210th Street. These points will serve as accesses for both vehicles andtrucks.

D1.1 Alternatives Evaluated

Three alternatives were initially proposed for evaluation, each representing a different mixof land uses that would generate differing levels of traffic. These alternatives were:

Alternative 1 Includes a 50%/25%/25% allocation of manufacturing/logistics/office


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CHAPTER D2

Existing Conditions

This chapter discusses the site conditions, transportation facilities, traffic volumes, and p.m.peak-hour operations as they currently exist. This establishes a basis for comparisonbetween existing traffic conditions, future No Build traffic conditions, and the proposedtraffic conditions for the two development alternatives.

D2.1 Site Conditions and Adjacent Land Uses

The site is located in northern Des Moines, Washington, south of Seattle-TacomaInternational Airport. The site is currently vacant and identified on the Greater Des MoinesComprehensive Plan Preferred Land Use Map as Business Park. The site is located lessthan a mile from both Pacific Highway South and Interstate 5. Land adjacent and to the westis designated as Park and Public Facility. Land adjacent and to the south is designated asBusiness Park. Land adjacent and to the east is designated as Business Park andCommercial. Land to the north is located within the city of SeaTac, and includes the TyeeValley Golf Course.

D2.2 Transportation Facilities

The primary roadways providing access to the proposed site are South 216th Street and 24th


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South 208th Street South 208th Street is a 2-lane local collector arterial locatedimmediately northeast of the development site. It connects to SR 99 to the east; its

western end is at the northern edge of the development site.

24th Avenue South 24th Avenue South is a 2-lane north/south local minor arterialroadway located immediately east of the development site. It connects to South 208thStreet to the north, and SR 516 to the south.

SR 99 SR 99 travels north-south, and is one of the primary regional routes located nearthe DMCBP site. It is located less than a half-mile east of the site. SR 99 connects south tothe cities of Kent, Federal Way, and Tacoma and connects north to Sea-Tac Airport and

the cities of SeaTac, Tukwila, and Seattle. Within the city of SeaTac, SR 99 is also knownas International Boulevard, while within the city of Des Moines, it is known as PacificHighway South. In Des Moines, SR 99 has a 7-lane cross-section (including southboundand northbound high-occupancy vehicle [HOV] lanes), with a center raised median thatbecomes a left-turn storage lane at intersections. In SeaTac, SR 99 has 6 lanes (including asouthbound HOV lane).

D2.3 Existing Volumes and Traffic OperationsExisting traffic volumes and traffic operations are indications of how the roadway networkin the study area is performing today. A review of the a.m. and p.m. peak hour traffic dataindicated that the p.m. peak hour is the peak travel period. To provide an analysis thatanalyze the most congested period, the p.m. peak hour is reported.


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condition. The weekday p.m. peak hour for the study area intersections was found to occurgenerally between 5:00 p.m. and 6:00 p.m.

The following study intersections were examined:

Signalized:

International Boulevard (SR 99)/South 188th Street




Pacific Highway South (SR 99)/SR 516 South 188th Street/28th Avenue South

South 188th Street/Des Moines Memorial Drive

South 200th Street/26th Avenue South

South 216th Street/Military Road South

Unsignalized:

South 208th Street/24th Avenue South South 216th Street/24th Avenue South

D2.3.3 Operational Analysis Methods

Operational analysis of both existing and future conditions for the study area intersectionswas performed using Synchro analysis software, version 6. Report results are based on


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The intersection peak hour factor (PHF) under future conditions was adjusted to be either0.85 (to account for existing low approach PHFs) or 0.90 for 2008 and 0.95 in 2015 to account

for the higher level of traffic congestion along major arterials. This had a relatively minimaleffect on traffic operations, because most intersections currently operate near or at these twoPHFs. To provide an accurate comparison, signal timings were not initially optimized inmodeling the future conditions. As part of any improvement package, the signalcoordination and optimization would be reviewed to ensure that the most effective timingplan is implemented.

D2.3.4 Mobility Standards

LOS mobility standards are set by the local agencies as a method to establish reasonable andconsistent standards for traffic flow. Mobility standards consider the classification andlocation (e.g., rural or urban) of roadways. The mobility standards that apply to the DMCBPstudy area are shown in Table D-4.

TABLE D-4

Applicable Mobility Standards for Des Moines Creek Business Park Traffic Study

Roadway Classification LOS Standard

International Boulevard (within City of SeaTac) LOS E

International Boulevard at South 188th Street and South 200thStreet

LOS Fa

Pacific Highway South (within City of Des Moines) LOS E

b


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operate at LOS E, while the intersection of Pacific Highway South and SR 516 operates atLOS F. LOS calculation sheets are provided in the operational analysis results available from

the Port. Table D-5 provides a summary of the existing intersection LOS analysis. Existingp.m. peak hour volumes, LOS, and channelization for study area intersections aresummarized in Figure D-2.

TABLE D-5

Existing p.m. Peak-Hour Intersection Levels of Service (2005)

Intersection p.m. Peak Hour

Existing

LOS

Delay

(sec./veh.) Jurisdiction

LOS

Standard

International Boulevard (SR 99)/South 188th Street E 72.8 State F

International Boulevard (SR 99)/South 200th Street E 60.9 State F

International Boulevard (SR 99)/South 208th Street B 15.9 State E

International Boulevard (SR 99)/South 216th Street D 47.6 State F

Pacific Highway South (SR 99)/SR 516 F 100.4 State F

South 188th Street/28th Avenue South C 25.0 SeaTac ESouth 188th Street/Des Moines Memorial Drive D 37.0 SeaTac E

South 216th Street/Military Road South C 33.3 SeaTac E

South 200th Street/26th Avenue South A 9.3 SeaTac E

South 208th Street/24th Avenue Southa B 10.8 SeaTac E


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1 South 188th Street & DM Memorial Drive 2 28th Avenue South & South 188th Street 3 SR 99 & South 188th Street 4 26th Avenue South & South 200

LOS LOS LOS

2005 Existing D 2005 Existing C 2005 Existing E 2005 Existing

5 35 225 1215 425 45 330

5 5 10 750 35 20 60 810 HOV 515 55 10 155

70 170 265

5 40 225 15

1030 570 5 115 1215 80 15 130 765 25 270 590 220 600 5

1270 180 395 5

5 SR 99 & South 200th Street 6 24th Avenue South & South 208th Street 7 SR 99 & South 208th Street 8 24th Avenue South & South 216

LOS LOS LOS

2005 Existing E 2005 Existing B 2005 Existing B 2005 Existing

75 1170 340 20 105 5 105 2060 160 60 95

HOV 240 5 5 HOV 20 75 40 10

210 95 60

65 40 10

490 15 95 520 115 5 30 15 30 25 1035 85 285 2

275 15 60

9 SR 99 & South 216th Street 10 Military Road South & South 216th Street 11 SR 99 & SR 516

LOS LOS

2005 Existing D 2005 Existing C 2005 Existing

200 1545 155 50 70 20 105 1575 650 60

Turning Movement Direction HOV 385 190 285 20 245

165 260

SIGNAL Signalized intersection

AWSC All-way stop-controlled intersection 130 140 90

TWSC Two-way stop-controlled intersection 225 25 120 725 105 75 110 185 30 490

LOS Level of service of intersection, 140 200 125 25 11

based on approach delay in seconds

Peak-Hour Turning Volumes

2005 Existing LOS 2005 Existing

LOS A - E*

LOS F

* 2005 Existing

HOV

2005 Existing Conditions Intersection Volumes/LOS/Cha

Intersection Number

Control Delay (sec) Control Delay

SIGNAL 100SIGNAL 33.3

Con tr ol Del ay (s ec )

SIGNAL 47.6

TWSC 38SIGNAL 15.9

Control Delay (sec) Control Delay (sec) Control Delay

Con tr ol Del ay

SIGNAL 9


SIGNAL 25.0


SIGNAL 72.8


SIGNAL 37.0

LEGEND


TWSC 10.8

LOS D is the threshold at Des Moines intersections fornon-SR 99 and LOS F at SR 99/216th St and SR99/SR 516 in the City's 2001 Comprehensive Plan.Likewise, within the city of Seatac the allowable LOSthreshold is F at International Blvd (IB) @ 188th andIB @ 200th.

SIGNAL 60.9

2005

Existing

2005

ExistingN

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth

InternationalBoulevard

28th/24th

AvenueSouth

DesMoinesMemorialDrive


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CHAPTER D3

Future Conditions

This chapter presents information on future development plans and development phasing,as well as future traffic impacts expected related to the development of DMCBP. Futuretraffic impacts with the development are compared to expected future operations withoutthe development to show its relative effects.

D3.1 No Build Traffic Forecasts

In order to assess the impact of the DMCBP development on the surrounding transportationnetwork, it is first important to establish No Build traffic forecasts for the years of analysis(2008 and 2015). These forecasts represent the level of future traffic anticipated in the studyarea without development of the DMCBP site. The future traffic levels anticipated with theproposed development of the site are then compared against the No Build future condition

to assess the projects effect on traffic operations within the study area.

The No Build forecasts also reflect the completion of transportation projects that are plannedby agencies in the project area for future years. The same planned transportation projectsare assumed in the forecasts that include anticipated traffic from the DMCBP development.This allows the analysis to draw a clear comparison between forecasts with and without the


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South 200th Street, South 216th Street, SR 516, Marine View Drive, and 16th Avenue South.The 2 percent per year growth rate was applied to the existing traffic volumes to create two

No Build forecasts: one for 2008 and one for 2015.

D3.2 Traffic Forecasts for Build Alternatives

The traffic impact generated by the proposed development during the p.m. peak hour wasanalyzed as follows:

The total number of project-related peak-hour trips was estimated based on the

proposed developments land use characteristics. Estimated site-generated traffic was added to the future forecasted background volumes

to determine future traffic volume levels at key intersections within the study area.

Traffic operations at key intersections for the full site buildout were analyzed using theexpected future background traffic volumes and the site-generated traffic.

The remainder of this section describes the results of the 2008 and 2015 analyses for the

build alternatives and the No Build alternative.

D3.2.1 Development Site Trip Generation and Distribution

Prior to analyzing operations for the proposed DMCBP development, trip generation anddistribution assumptions for the development were developed. Trip generation estimatesfor the business park during the p.m. peak hour were based on average trip rates for similar


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the lowest traffic levels, while manufacturing-type businesses generate trip levels that areintermediate between the two other land use types. Attachment D-3 provides more

information on trip generation calculations for all three alternatives.

TABLE D-6

Preliminary Alternative 1 Estimated Trip Generation

Total Weekday p.m.Peak Hour Trips

Weekday p.m. PeakHour Truck Trips

Land UseAmount(sq. ft.)

TotalWeekday

Daily Trips

TotalWeekday

Daily TruckTrips In Out Total In Out Total

Manufacturing 500,000 2,480 215 96 334 430 8 27 35

Logistics 250,000 1,140 100 29 88 117 2 7 9

Office/R&D 250,000 2,270 45 48 265 313 1 5 6

Total 1,000,000 5,890 360 173 687 860 11 39 50

Note: Trips generated are calculated using ITE trip generation average rates.

TABLE D-7Preliminary Alternative 2 (Alternative A) Estimated Trip Generation

Total Weekday p.m.Peak Hour Trips

Weekday p.m. PeakHour Truck Trips

Land UseAmount(sq. ft.)

TotalWeekday

Daily Trips

TotalWeekday

Daily TruckTrips In Out Total In Out Total


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Because Alternative 1 represented an intermediate condition between the other twoalternatives, it was subsequently determined that only Alternatives 2 and 3 (which were

renamed A and B) would be evaluated in detail. These two alternatives reflect what isconsidered to be a reasonable range of traffic conditions for the DMCBP, given Port and Cityobjectives for the project, foreseeable market conditions, and the physical setting of theproperty. Each of the development alternatives includes approximately 1,000,000 square feetof building area at full buildout.

Trip distribution of site-generated traffic onto the roadway system was estimated based onthe location of the site, existing traffic counts, and the travel patterns likely to occur duringthe p.m. peak hour. The trip distribution assumptions were consistent between

Alternatives A and B. Most project-related trips are expected to travel either north or south,with approximately 50 percent of vehicles traveling to and from the north and 40 percenttraveling to and from the south. Of the remaining 10 percent, 7 percent of vehicles would betraveling to and from the east and 3 percent would be traveling to and from the west.

A majority of the trips traveling to and from the north on the arterial system are airport-related. Trips to the north that access either the airport or SR 509 are assumed to be splitbetween 28th Avenue South and International Boulevard. Trips heading north through the

City of SeaTac or to northbound I-5 are assumed to use International Boulevard. A majorityof southbound traffic would use Pacific Highway South, with only a small percentageassumed to use 24th Avenue South. Trip distribution percentages for Alternatives A and Bare presented in Figure D-3. Trip assignments for Alternative A and Alternative B arepresented in Figures D-4 and D-5, respectively.

Truck traffic generated by the development is expected to access the regional arterials and


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S.216th St.

S.208th St.

S.188th St.

DesM

oine

sMem

orial

Drive

P a c

i f i c

H i g h

w a y

S .

I n t e

r n a

t i o n a

l B

o u

l e v

a r d

S.200th St.

28th/24th

Ave.

S.

AngleLake

DesMoine

sCre

ek

20%

10%

20%


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0 5 0

0 0 0 120 0 0 0 60 0 30 0 0 0 0 0 15

0 0 15

0 0 0 0

30 0 0 0 15 60 5 0 0 0 65 110 40 0

0 15 0 0


0 0 0

0 60 0 0 0 0 0 45 45 0 0 0 10 25 105

15 45 0

0 155 0

0 0 65 215 30 0 155 0 0 0 155 0 260

15 0 25

9 SR 99 & South 216th Street 10 Military Road South & South 216th St reet 11 SR 99 & SR 516

0 0

Turning Movement Direction 45 0 0 0 15 5 0 0 5 0 45 80

0 0

155 60 0

85 0 35 0 0 10 5 0 0 40 0

125 15 10

Alt. A Buildout

Trip Assignment

LEGEND

Intersection Number

Alt.ABuildoutTrip

Assignment

Alt.ABuildoutTrip

Assignment

Alt. A Buildout TripAssignment

Development Alternative A Trip

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24thAvenueSouth



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0 0 0 0 0 0 0 0 5 5 0 30 0 0 0 0 0 0 15

0 0 0 155 130 0 0 0 75 65 0 35 0 0 0 0 0 0 20

0 0 0 0 15 15

0 0 0 0 0 0 0 0

30 35 0 0 0 15 15 75 5 0 15 15 0 80 150 55 0 0

0 0 0 0 0 15 20 65 5 0 0 0 0 70 130 45 0 0


0 60 0 0 0 0 0 0 0 0 45 45 0 0 0 0 10 30 120

0 70 0 0 0 0 0 0 55 55 0 0 0 0 10 35 140

20 15 55 45 0 0

0 0 180 205 0 0

0 0 0 80 285 45 0 205 0 0 0 0 205 0 300 345

15 20 0 70 245 40 0 180 0 0 0 0 175 0 30 35


45 0 0 0 0 0 5 0 0 0 0 0 50 90

Turning Movement Direction 55 0 0 0 15 15 5 0 0 5 5 0 60 100

0 0 0 0

175 205 70 80 0 0

100 120 0 35 0 0 10 15 5 0 0 45 55 0

140 160 0 35 0 0 20 25 5 0 0 15 15 0

Alt B BuildoutTrip Assignment

Alt B Trip Assignment

(with L.U. revisions)

LEGEND

Intersection Number

Alt B Trip Assignment(with L.U. revisions)

AltBTripAssignment

(withL.U.revisions)

AltBTripAssignment

(withL.U.revisions)

Alt B Buildout Trip

Assignment

AltBBuildoutTrip

Assignment

AltBBuildoutTrip

Assignment

Development Alternative B Trip

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth

I

nternationalBoulevard

28th/24th

AvenueSouth

DesMo

inesMemorialDrive


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1 South 188th Street & DM Memorial Drive 2 28th Avenue South & South 188th Street 3 SR 99 & South 188th Street 4 26th Avenue South & South 200th Stre

LOS LOS LOS

2008 No Build D 2008 No Build C 2008 No Build E 2008 No Build

2008 Alt A D 2008 Alt A B 2008 Alt A E 2008 Alt A

5 5 10 5 5 40 25 65 40 45 240 1 320 4 50 50 350 350 60 10 180

5 5 15 795 915 40 25 65 860 920 240 1 290 455 50 550 545 60 10 165 3

75 75 180 180 285 295

5 5 45 45 240 240 15 20

1125 1095 605 5 125 1305 1290 85 20 140 810 815 30 290 625 235 640 640 5

1350 1350 605 5 125 205 195 145 20 140 435 420 30 350 740 275 5 5 5

5 SR 99 & South 200th Street 6 24th Avenue South & South 208th Street 7 SR 99 & South 208th Street 8 24th Avenue South & South 216th Stre

LOS LOS LOS

2008 No Build E 2008 No Build B 2008 No Build B 2008 No Build

2008 Alt A E 2008 Alt A B 2008 Alt A C 2008 Alt A

80 1300 360 25 115 115 5 5 5 5 160 2230 170 65 105 100 90 70 120 4

80 1240 360 25 255 255 5 5 115 2185 170 65 25 25 80 45 15 5

225 240 105 150 65 65 2

70 70 200 45 15 15

520 520 20 105 555 125 5 35 15 20 35 30 1 100 90 565 305 25 4

310 295 20 165 765 155 5 185 15 20 35 30 1255 90 90 65 30 5


LOS LOS

2008 No Build E 2008 No Build C 2008 No Build

2008 Alt A E 2008 Alt A D 2008 Alt A

Turning Movement Direction 260 1640 165 55 75 75 210 305 25 25 25 115 1 715 7 70 65 4

215 1640 165 55 410 425 205 305 25 260 265 115 1670 690 65 5

175 175 280 275 6


AWSC All-way-stop controlled intersection

TWSC Two-way-stop controlled intersection 295 140 210 150 95 95

LOS Level of service of intersection, 330 240 30 130 770 115 90 80 120 200 35 560 520 30 120 5

based on approach delay in seconds 275 150 30 160 770 115 230 215 120 200 35 145 135 30 120 6


2008 N o B ui ld 2008 A lt A

LOS A - E*

LOS F

*

TWSC 11.1

TWSC 14.4

C on tr ol D el ay (s ec )

93.6

LEGEND

2008AltA

2008

No

Build

2008 Alt A

2008 No Build

SIGNAL

Control Delay (sec) Control Delay (sec)

SIGNAL 94.5SIGNAL 34.3

59.2 SIGNAL SIGNAL37.7


SIGNAL 67.7

SIGNAL 8.0

SIGNAL 21.2

SIGNAL 18.9

SIGNAL 29.7

SIGNAL 9.6

Control Delay (sec) Control Delay (sec) Control Delay (sec)

SIGNAL 19.7

C on tr ol D el ay (s ec

SIGNAL 9.3

SIGNAL 59.1


SIGNAL 25.1

C on tr ol D el ay ( sec)

SIGNAL 77.4


SIGNAL

SIGNAL

44.5

46.6

Intersection Number

SIGNAL 66.4

SIGNAL 66.7

*NOTE: Alternative A results include signaloptimization and coordination.

LOS D is the threshold at Des Moines intersections fornon-SR 99 and LOS F at SR 99/216th St and SR 99/SR516 in the City's 2001 Comprehensive Plan. Likewise,within the city of Seatac the a llowable LOS threshold isF at International Blvd (IB) @ 188th and IB @ 200th.

2008 Alt A

2008AltA

2008

No

Build

2008 No Build

Fi

2008 No Build and Build Alt. A Intersection Volumes

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24thA

venueSouth

DesMoin

esMemorialDrive


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LOS LOS LOS

2008 No Build D 2008 No Build C 2008 No Build E 2008 No Build

2008 Alt B D 2008 Alt B B 2008 Alt B E 2008 Alt B

5 5 10 5 5 40 25 65 40 45 240 1320 450 50 350 350 60 10 180

5 5 15 795 930 40 25 65 860 925 240 1 290 455 50 550 545 60 10 1 65 3

75 75 180 180 285 295

5 5 45 45 240 240 15 20

1125 1095 605 5 125 1305 1290 85 20 140 810 815 30 290 625 235 640 640 5

1350 1350 605 5 125 205 195 155 20 140 435 420 30 360 755 280 5 5 5


LOS LOS LOS

2008 No Build E 2008 No Build B 2008 No Build B 2008 No Build

2008 Alt B E 2008 Alt B B 2008 Alt B C 2008 Alt B

80 1300 360 25 115 115 5 5 5 5 160 2230 170 65 105 100 90 75 135 4

80 1240 360 25 255 255 5 5 115 2185 170 65 25 25 80 4 5 15 5

225 240 105 150 65 65 2

70 70 220 45 15 15

520 520 20 105 555 125 5 35 15 20 35 30 1100 90 605 305 25 4

310 295 20 175 800 160 5 210 15 20 35 30 1 275 90 95 65 30 5


LOS LOS

2008 No Build E 2008 No Build C 2008 No Build

2008 Alt BE

2008 Alt BD

2008 Alt B


215 1640 165 55 410 425 205 305 25 260 265 115 1670 690 65 5

175 175 280 275 6




LOS Level of service of intersection, 340 240 30 130 770 115 95 80 120 200 3 5 565 520 30 120 5



2008 N o B ui ld 2008 A lt B

LOS A - E*

LOS F

*

2008 Alt B

2008AltB

2008

No

Build

2008 No Build

Fi

38.158.7Intersection Number

SIGNAL 66.4

SIGNAL 66.9


SIGNAL

SIGNAL

44.5

46.5 SIGNAL 59.5


SIGNAL 25.1


SIGNAL 77.4

C on tr ol D el ay (s ec

SIGNAL 9.3

SIGNAL 9.6

Control Delay (sec) Control Delay (sec) Control Delay (sec)

SIGNAL 19.9

24.3

SIGNAL 18.9

SIGNAL 31.8

SIGNAL


SIGNAL 67.7

94.7

Control Delay (sec) Control Delay (sec)


SIGNAL

LEGEND

2008AltB

2008

No

Build

2008 Alt B

2008 No Build

SIGNAL

SIGNAL 8.0

SIGNAL

TWSC 11.1

TWSC 14.8


2008 No Build and Build Alt. B Intersection Volume

LOS D is the threshold at Des Moines intersections fornon-SR 99 and LOS F at SR 99/216th St and SR99/SR 516 in the City's 2001 Comprehensive Plan.Likewise, within the city of Seatac the allowable LOSthreshold is F at International Blvd (IB) @ 188th and IB@ 200th.

*NOTE: Alternative B results include revising theland use percentages and signal optimizationand coordination.

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24thA

venueSouth

DesMoin

esMemorialDrive


27/64


Based on the City of Des Moines LOS standards, this LOS is acceptable. In addition,International Boulevard at South 188th Street and International Boulevard at South 200thStreet are expected to operate at LOS F in Alternative B. No other intersections under theCity of SeaTac jurisdiction are expected to operate at LOS F. The intersection LOS results areshown in Table D-9.

TABLE D-9

2008 p.m. Peak-Hour Intersection Analysis

2008 No Build 2008 Alt. A 2008 Alt. B

Intersection LOS Delay LOS Delay LOS Delay

International Boulevard/S. 188th St. E 77.5 E 79.7 F 81.3

International Boulevard/S. 200th St. E 66.4 E 76.5 F 80.4

International Boulevard/S. 208th St. B 18.9 D 44.4 E 55.9

International Boulevard/S. 216th St. E 67.7 F 85.5 F 93.3

Pacific Highway South/SR 516 F 94.5 F 106.4 F 111.9

S. 188th Street/28th Avenue S. C 25.1 C 27.6 C 28.3

S. 200th Street/26th Avenue S. A 9.3 A 9.6 A 9.6

S. 208th Street/24th Avenue S. B 11.1 B 14.4 C 15.6

S. 216th Street/24th Avenue S. A 8.0 B 17.4 C 26.0

S. 188th Street/Des Moines Mem. Dr. D 44.5 D 46.6 D 46.8

S. 216th Street/Military Road S. C 34.3 D 37.7 D 38.7

Notes:


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TABLE D-10

2015 p.m. Peak-Hour Intersection Analysis

2015 No Build 2015 Alt. A 2015 Alt. B

Intersection LOS Delay LOS Delay LOS Delay

International Boulevard/S. 188th St. F 87.9 F 94.8 F 97.2

International Boulevard/S. 200th St. E 78.4 F 93.3 F 97.7

International Boulevard/S. 208th St. C 21.4 E 59.8 E 77.7

International Boulevard/S. 216th St. F 92.6 F 106.1 F 110.0

Pacific Highway South/SR 516 F 123.3 F 138.4 F 143.2

S. 188th Street/28th Avenue S. C 26.1 D 38.1 D 41.5

S. 200th Street/26th Avenue S. A 9.5 A 9.8 A 9.8

S. 208th Street/24th Avenue S. B 11.3 B 14.5 C 15.8

S. 216th Street/24th Avenue S. A 8.4 B 18.5 C 27.7

S. 188th Street/Des Moines Mem. Dr. E 64.9 E 67.1 E 67.3

S. 216th Street/Military Road S. D 37.7 D 46.5 D 48.1

Notes:

Refer to Table D-4 for the applicable LOS standards.Underlined results indicate an unsignalized intersection.


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1 South 188th Street & DM Memorial Drive 2 28th Avenue South & South 188th Street 3 SR 99 & South 188th Street 4 26th Avenue South & South 200th St

LOS LOS LOS

2015 No Build E 2015 No Build C 2015 No Build F 2015 No Build

2015 Alt A D 2015 Alt A C 2015 Alt A E 2015 Alt A

10 10 15 10 10 45 25 75 45 50 270 1490 510 50 400 400 70 15 205

10 10 15 900 1020 45 25 70 975 1030 270 1460 510 50 620 620 70 15 190

85 85 205 205 320 335

10 10 50 50 270 270 20 20

1270 1240 685 10 140 1475 1460 100 20 160 920 920 30 325 710 265 720 720 10

1525 1525 685 10 140 235 220 155 25 160 490 475 30 390 820 305 10 10 10

5 SR 99 & South 200th Street 6 24th Avenue South & South 208th Street 7 SR 99 & South 208th Street 8 24th Avenue South & South 216th St

LOS LOS LOS

2015 No Build E 2015 No Build B 2015 No Build C 2015 No Build

2015 Alt A E 2015 Alt A B 2015 Alt A D 2015 Alt A

90 1465 410 25 130 130 10 10 10 10 175 2 520 195 65 115 115 100 75 120

90 1405 410 25 290 290 10 10 130 2475 195 65 25 25 90 5 0 15

255 270 115 160 75 75

80 80 205 50 15 15

590 590 20 115 625 140 10 40 20 20 35 30 1245 105 605 345 25

350 330 20 180 840 175 10 90 20 20 35 30 1400 1 05 100 75 30


LOS LOS

2015 No Build F 2015 No Build D 2015 No Build

2015 Alt A E 2015 Alt A D 2015 Alt A


240 1855 190 55 465 480 230 345 25 295 300 130 1890 780 65

200 200 315 315




LOS Level of service of intersection, 360 270 30 145 870 130 105 90 135 225 40 630 590 30 135



2015 N o B ui ld 2015 A lt A

LOS A - E*

LOS F

*

2015 Alt A

2015AltA

2015

No

Build

2015 No Build

F

46.573.7Intersection Number

SIGNAL 78.4

SIGNAL 76.4


SIGNAL

SIGNAL

64.9

48.3 SIGNAL 70.5


SIGNAL 26.1


SIGNAL 87.9

C on tr ol D el ay (s e

SIGNAL 9.5

SIGNAL 9.8

Control Delay (sec) Control Delay (sec) Control Delay (se

SIGNAL 20.6

20.9

SIGNAL 21.4

SIGNAL 36.9

SIGNAL


SIGNAL 92.6

113.5

Control Delay (sec) Control Delay (se


SIGNAL

LEGEND

2015AltA

2015

No

Build

2015 Alt A

2015 No Build

SIGNAL

SIGNAL 8.4

SIGNAL

TWSC 11.3

TWSC 14.5


2015 No Build and Build Alt A. Intersection Volum

LOS D is the threshold at Des Moines intersections fornon-SR 99 and LOS F at SR 99/21 6th St and SR 99/SR516 in the City's 2001 Comprehensive Plan. Likewise,within the city of Seatac the allowable LOS threshold isF at International Blvd (IB) @ 188th and IB @ 200th.

*NOTE: Alternative A results include signaloptimization and coordination.

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24th

AvenueSouth



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1 South 188th Street & DM Memorial Drive 2 28th Avenue South & South 188th Street 3 SR 99 & South 188th Street 4 26th Avenue South & South 200th S

LOS LOS LOS

2015 No Build E 2015 No Build C 2015 No Build F 2015 No Build

2015 Alt B D 2015 Alt B C 2015 Alt B E 2015 Alt B

10 10 15 10 10 45 2 5 75 45 50 270 1 490 5 10 50 400 400 70 15 205

10 10 15 900 1035 45 2 5 70 975 1040 270 1 460 510 50 620 620 70 15 190

85 85 205 205 320 335

10 10 50 50 270 270 20 20

1270 1240 685 10 140 1475 1460 100 20 160 920 920 30 325 710 265 720 720 10

1525 1525 685 10 140 235 220 165 2 5 160 490 475 30 395 840 310 10 10 10

5 SR 99 & South 200th Street 6 24th Avenue South & South 208th Street 7 SR 99 & South 208th Street 8 24th Avenue South & South 216th S

LOS LOS LOS

2015 No Build E 2015 No Build B 2015 No Build C 2015 No Build

2015 Alt B E 2015 Alt B C 2015 Alt B D 2015 Alt B

90 1465 410 25 130 130 10 10 10 10 175 2520 195 65 115 115 100 80 135

90 1405 410 25 290 290 10 10 130 2475 195 65 25 25 90 5 0 15

255 270 115 160 75 75

80 80 230 50 15 15

590 590 20 115 625 140 10 40 20 20 35 30 1245 105 645 345 25

350 330 20 185 870 180 10 215 20 20 35 30 1420 1 05 105 75 30


LOS LOS

2015 No Build F 2015 No Build D 2015 No Build

2015 Alt B E 2015 Alt B D 2015 Alt B

Turning Movement Direction 290 1855 190 55 85 85 235 345 25 25 25 130 1 945 870 65

240 1855 190 55 465 480 230 345 25 295 300 130 1890 780 65

200 200 315 315




LOS Level of service of intersection, 375 270 30 145 870 130 105 90 135 225 4 0 635 590 30 135

based on approach delay in seconds 310 170 30 180 870 130 260 240 140 225 40 165 150 30 135


2015 N o B ui ld 2015 A lt B

LOS A - E*

LOS F

*

TWSC 11.3

TWSC 15.0


115.1

LEGEND

2015AltB

2015

No

Build

2015 Alt B

2015 No Build

SIGNAL

Control Delay (sec) Control Delay (s


76.6 SIGNAL SIGNAL47.0


SIGNAL 92.6

SIGNAL 8.4

SIGNAL 24.3

SIGNAL 21.4

SIGNAL 40.0

SIGNAL 9.8

Control Delay (sec) Control Delay (sec) Control Delay (s

SIGNAL 20.6

C on tr ol D el ay (s

SIGNAL 9.5

SIGNAL 71.4


SIGNAL 26.1


SIGNAL 87.9


SIGNAL

SIGNAL

64.9

48.2

Intersection Number

SIGNAL 78.4

SIGNAL 79.1

*NOTE: Alternative B results include revising theland use percentages and signal optimization andcoordination.

LOS D is the threshold at Des Moines intersections fornon-SR 99 and LOS F at SR 99/216th St and SR 99/SR516 in the City's 2001 Comprehensive Plan. Likewise,within the city of Seatac the allowable LOS threshold isF at International Blvd (IB) @ 188th and IB @ 200th.

2015 Alt B

2015AltB

2015

No

Build

2015 No Build

2015 No Build and Build Alt B. Intersection Volum

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24th

AvenueSouth

DesMoi

nesMemorialDrive


31/64



HOV HOV

HOV HOV


HOV

HOV

Turning Movement Direction


AWSC All-way stop-controlled intersection

TWSC Two-way stop-controlled intersection

LOS Level of service of intersection,

based on approach delay in seconds

No Build Lane Channelization

2008/2015 No Build

2008/2015 Alt A and Alt B

HOV

HOV

Future Alt Lane Channelization

Stop-controlled Intersection / Approach

Signalized Intersection

HOV

Future No Build, Alt A. and Alt. B Intersection ChannIntersection is Signalized (as part of No

Build)

LEGEND

HOV

Intersection Number

Fig

N

South 188th Street

South 200th Street

South 216th Street

PacificHighwaySouth


28th/24th

AvenueSouth



32/64

CHAPTER D4

Recommended Mitigation Measures

Based on the modeling results described above, all project intersections would operate atlevels of service consistent with the standards of local jurisdictions under Alternatives Aand B in both 2008 and 2015. This is because the Cities of SeaTac and Des Moines haveadopted LOS standards of F at four key intersections of International Boulevard/PacificHighway South (South 188th Street, South 200th Street, South 216th Street, and SR 516).

However, as shown in Tables D-9 and D-10, the project would result in additional delay atthese intersections as compared to No Build conditions. Accordingly, the Port evaluatedstrategies to improve operations along International Boulevard/Pacific Highway South forboth 2008 and 2015 conditions. Although not required, these strategies could be used tobring the intersections back to levels of delay consistent with No Build conditions, therebymitigating project-related impacts.

Because the DMCBP development is expected to alter traffic patterns, signal timing

optimization and coordination were assumed as the initial improvement strategy. Modelingof these improvements resulted in improved intersection operations for both developmentalternatives to LOS E or better in 2008, except at Pacific Highway South and SR 516. Thisintersection is expected to continue to operate at LOS F, but with overall delay similar to NoBuild. Refer to Table D-11 for the intersection LOS summary with and without signal timingimprovements


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Similarly, signal improvements were modeled for both development alternatives for 2015.For Alternative A, which generates fewer trips overall, this strategy is expected to improvethe intersection operations to be LOS E or better, except at Pacific Highway South and

SR 516. This intersection is expected to continue to operate at LOS F, but with a reduction inoverall delay.

In Alternative B, even with signal improvements, some Pacific Highway/InternationalBoulevard intersections would continue to operate at LOS F in 2015, with greater levels ofdelay than under No Build conditions. Bringing this alternative back to No Build conditionswould require either the addition of new roadway capacity (e.g., completion of SR 509) or areduction in the number of trips generated by the project. Because SR 509 is not planned for

construction by 2015, adjustment of the land use mixture for this alternative was analyzedas a next step. Altering the land use percentages so that the development would create nomore than 830 p.m. peak hour trips, and optimizing the signal phasing, would improve theintersection operations to be LOS E or better, except at Pacific Highway South and SR 516.This intersection is expected to continue to operate at LOS F, but with a reduction in overalldelay as compared to No Build. Refer to Table D-12 for the intersection LOS summary withthe proposed improvements.

TABLE D-122015 p.m. Peak-Hour Improved Intersection Analysis

2015 No Build 2015 Alt. A2015 Alt. AImproved 2015 Alt. B

2015 Alt. BImproved

Intersection LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay

International Boulevard/S 188th St F 87 9 F 94 8 E 70 5 F 97 2 E 71 4


34/64

CHAPTER D5

Conclusions and Recommendations

Based on the results of the traffic impact analysis described in this report, it appears thatmost or all of the proposed development can be built out while maintaining an acceptableLOS and safe conditions at the site driveways. The analysis resulted in the followingconclusions and recommendations:

Buildout of both alternatives is expected to meet agency LOS thresholds in both 2008and 2015. However, if desired, signal optimization and International Boulevard/PacificHighway corridor progression could be used to restore intersection operations to NoBuild LOS thresholds for Alternative A and to improve operations for Alternative B.(Signal optimization is assumed in the Alternative A Improved and Alternative BImproved columns of Table D-2.) Impacts to International Boulevard in the City ofSeaTac are minimized, as northbound trips on International Boulevard occur primarilyin the PM peak hour. Because this is the non-peak direction at this time, there is

available capacity to accommodate these trips without the addition of new capacity.

Buildout of Alternative B would generate greater traffic impacts than Alternative Abecause of the higher number of trips associated with the increased office space. Signaloptimization alone would not be sufficient to bring Alternative B back to No Build levelsof delay without the development of new capacity through SR 509 or a project of similar


35/64


Although not considered as part of this study, the SR 509 and 28th/24th Avenue Southextension projects would be expected to significantly improve traffic operations in thearea. The majority of traffic from DMCBP would likely use these two corridors to access

the airport and Interstate 5. This would further improve traffic operations alongInternational Boulevard/Pacific Highway South. Traffic analysis for the DMCBPprojects environmental documentation (see Chapter 5 of the Conceptual Master Plan)will model post-2015 traffic operations in the project area with SR 509 and the28th/24th Avenue South extension.


36/64

Attachment D-1

Traffic Count Data


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43/64


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Peak Hour Summary

5:00 PM to 6:00 PM

Wednesday, July 06, 2005

214 17

55 7 152

5

0 381 325 335 0

5

0 0

26th Ave S & 200th

26thA

veS

200th 0Peds

Mark Skaggs

(206) 251-0300


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Total Vehicle Summary

26th Ave S & 200th

4:00 PM to 6:00 PM

15-Minute Interval Summary

4:00 PM to 6:00 PMInterval Northbound Southbound Eastbound Westbound Pedestrians

Start 26th Ave S 26th Ave S 200th 200th Interval Crosswalk

Time L T R HV L T R HV L T R HV L T R HV Total North South East West

04:00 PM 1 0 10 0 33 0 7 1 5 107 2 1 1 67 2 3 235 0 0 0 0

04:15 PM 0 0 1 0 29 0 6 1 1 115 2 5 0 65 1 4 220 0 0 0 0

04:30 PM 0 0 1 0 26 0 9 1 2 144 0 3 1 71 1 4 255 0 1 0 0

04:45 PM 1 0 2 0 25 0 5 1 3 118 0 6 1 78 1 3 234 1 2 1 0

05:00 PM 0 0 2 0 24 0 10 1 4 153 1 0 2 94 0 2 290 0 0 0 0

05:15 PM 1 0 3 0 37 2 14 0 1 135 0 7 1 76 2 1 272 0 3 0 0

05:30 PM 0 1 5 0 51 2 15 2 3 166 1 0 1 69 2 2 316 0 1 0 1

05:45 PM 0 0 6 0 40 3 16 1 3 144 3 2 1 86 1 5 303 0 1 0 0

Total Survey 3 1 30 0 265 7 82 8 22 1,082 9 24 8 606 10 24 2,125 1 8 1 1

Peak Hour Summary

5:00 PM to 6:00 PM

Northbound Southbound Eastbound Westbound Pedestrians

26th Ave S 26th Ave S 200th 200th Total Crosswalk

In Out Total HV In Out Total HV In Out Total HV In Out Total HV North South East West

Volume 18 17 35 0 214 17 231 4 614 381 995 9 335 766 1,101 10 1,181 0 5 0 1


By

Approach

Mark Skaggs

(206) 251-0300

11

598

5

5

325

5

161

7 15255

0

5

1 0

1

1817InOut

17214OutIn

614In

381Out

Out766

In335

0.7

5

PHF

0.0

%

HV

0.87PHF3.0%HV

0.90PHF1.5%HV

0.7

9

PHF

1.9

%

HV

Peak Hour Summary

5:00 PM to 6:00 PM


46/64

Peak Hour Summary

5:00 PM to 6:00 PM


107 86

31 18 58

35

0 919 808 1010 0

167

0 0

28th Ave S & S 188th St

28thA

veS

S 188th St 2Peds

Mark Skaggs

(206) 251-0300

O tI%


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28th Ave S & S 188th St

4:00 PM to 6:00 PM



Start 28th Ave S 28th Ave S S 188th St S 188th St Interval Crosswalk


04:00 PM 32 4 25 2 18 17 14 6 12 286 46 9 12 179 8 8 653 0 0 1 3

04:15 PM 24 11 27 3 9 12 6 2 7 318 33 17 8 173 5 5 633 0 1 0 1

04:30 PM 25 6 20 1 9 4 5 4 10 261 32 9 12 212 9 11 605 1 0 1 2

04:45 PM 21 6 24 4 15 7 12 7 17 301 44 9 15 169 11 9 642 0 0 0 0

05:00 PM 21 4 35 2 11 5 5 4 6 326 45 15 21 216 5 13 700 1 0 0 1

05:15 PM 23 1 34 1 15 5 6 10 10 301 51 7 40 196 13 13 695 0 0 0 0

05:30 PM 16 4 28 1 17 2 10 5 8 292 37 10 62 199 7 10 682 1 0 0 1

05:45 PM 20 6 33 2 15 6 10 2 12 292 44 7 44 197 10 7 689 0 2 0 0

Total Survey 182 42 226 16 109 58 68 40 82 2,377 332 83 214 1,541 68 76 5,299 3 3 2 8

Peak Hour Summary

5:00 PM to 6:00 PM


28th Ave S 28th Ave S S 188th St S 188th St Total Crosswalk


Volume 225 362 587 6 107 86 193 21 1,424 919 2,343 39 1,010 1,399 2,409 43 2,766 2 2 0 2


By

Approach

Mark Skaggs

(206) 251-0300

36

1,211

177

35

808

167

13080

18 5831

2

2

2 0

15

225362InOut

86107OutIn

1,424In

919Out

Out1,399

In1,010

0.9

4

PHF

2.7

%

HV

0.94PHF4.3%HV

0.94PHF2.7%HV

0.8

6

PHF

19

.6%

HV

Peak Hour Summary

5:00 PM to 6:00 PM


48/64

Peak Hour Summary

5:00 PM to 6:00 PM


1584 683

74 1170 340

105

0 403 236 548 0

207

0 0

SR 99 & 200th

S

R

99

200th 4Peds

Mark Skaggs

(206) 251-0300

OutIn


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SR 99 & 200th

4:00 PM to 6:00 PM



Start SR 99 SR 99 200th 200th Interval Crosswalk


04:00 PM 17 133 28 7 78 210 17 11 32 83 35 5 28 51 27 4 739 0 1 6 0

04:15 PM 28 134 27 5 101 189 17 9 18 130 44 9 34 52 33 1 807 0 7 3 1

04:30 PM 26 132 25 11 80 253 15 9 15 107 41 7 36 40 37 4 807 2 8 7 2

04:45 PM 32 109 21 8 87 208 12 13 8 110 66 3 30 59 29 4 771 0 4 4 0

05:00 PM 28 149 32 7 95 277 15 9 14 113 54 3 41 65 23 3 906 2 3 0 0

05:15 PM 24 119 14 10 68 266 22 10 13 110 75 7 61 68 28 3 868 1 11 1 1

05:30 PM 17 140 33 6 91 328 21 16 15 119 68 7 57 45 21 5 955 0 7 0 1

05:45 PM 24 109 34 7 86 299 16 11 19 146 77 2 48 58 33 2 949 1 6 0 0

Total Survey 196 1,025 214 61 686 2,030 135 88 134 918 460 43 335 438 231 26 6,802 6 47 21 5

Peak Hour Summary

5:00 PM to 6:00 PM


SR 99 SR 99 200th 200th Total Crosswalk


Volume 723 1,651 2,374 30 1,584 683 2,267 46 823 403 1,226 19 548 941 1,489 13 3,678 4 27 1 2


By

Approach

Mark Skaggs

(206) 251-0300

61

488

274

105

236

207

11393

1,170 34074

4

27

2 1

517

7231,651InOut

6831,584OutIn

823In

403Out

Out941

In548

0.8

6

PHF

4.1

%

HV

0.87PHF2.4%HV

0.85PHF2.3%HV

0.9

0

PHF

2.9

%

HV

Peak Hour Summary

5:00 PM to 6:00 PM


50/64


51/64


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53/64


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Attachment D-2

LOS Description



55/64

TABLE 1

Intersection Level of Service Criteria

Level of ServiceAverage Delay

(seconds per vehicle) Traffic Flow Characteristics

Signalized Intersections

A < 10 Most vehicles arrive during the green phase and do notstop at all.

B > 10 - < 20 More vehicles stop, causing higher delay.

C > 20 - < 35 Vehicles stopping is significant, but many still pass

through the intersection without stopping.

D > 35 - < 55 Many vehicles stop, and the influence of congestionbecomes more noticeable.

E > 55 - < 80 Very few vehicles pass through without stopping.

F > 80 Considered unacceptable to most drivers. Intersectionis not necessarily over capacity, even though arrivalsexceed capacity of lane groups.

Unsignalized Intersections

A < 10 Little or no traffic delays

B > 10 - < 15 Short traffic delays

C > 15 - < 25 Average traffic delays


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Attachment D-3

Site Trip Generation Spreadsheet

Des Moines Creek Business Park Development Light rail reduction Passby reducti on

Preliminary Alternative 1Weekday, Peak Hour of Adjacent Street Traffic, One Hour Between 4 and 6 p.m. 0% 0%

Land Use DescriptionLand Use Code

Planned Land Use (i.e. sq.

ft dwelling units acres)

Weighting

%

Weighted

Size Trip Rates Unit Trips Generated Fi l A

Internally

C t d T i

Directional

Di t ib ti D f t A

Light Rail

R d ti

Retail Passby

R d ti

Truck Traffic

R d ti


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pLand Use Code ft., dwelling units, acres) % Size Trip Rates Unit Trips Generated

Average Average Entering Exiting Entering Exiting Entering Exiting Entering Exiting Entering Exiting Entering Exiting Entering Exiting Notes

Manufacturing 1,000,000 50% 430 96 334 8% 88 307

Light Industrial (110) 0.25 250,000 0.98 1000 sf area 245 12% 88% 29 216 0 0 2 17 27 198 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho

Manufacturing (140) 0.25 250,000 0.74 1000 sf area 185 36% 64% 67 118 0 0 5 9 61 109 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho

Distribution 1,000,000 25% 118 29 88 8% 27 81

Warehousing (150) 0.25 250,000 0.47 1000 sf area 118 25% 75% 29 88 0 0 2 7 27 81 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho

1,000,000 25% 321 52 269 2% 47 260

General Office (710) 0.13 125,000 1.49 1000 sf area 186 17% 83% 32 155 4 4 0 0 1 3 27 147 Peak hour of generator coincided with adjacent traffic.

Research and Development (760) 0.13 125,000 1.08 1000 sf area 135 15% 85% 20 115 0 0 0 2 20 113 Truck trips are 0.4-4.0% of weekday traffic and peak hour of generator coincided with adjacen

Totals 1,000,000 1.00 1,000,000 869 177 691 0 11 39 162 648

Office with Research & Development

Final AverageCaptured TripsDist r ibution Draf t Average Reduction ReductionReduction

1/6/2006


Alternative A (aka Alt. 2)Weekday, Peak Hour of Adjacent Street Traffic, One Hour Between 4 and 6 p.m. 0% 0%



ft dwelling units acres)

Weighting

%

Weighted

Size Trip Rates Unit Trips Generated Final Average

Internally

Captured Trips

Directional

Dist r ibution Draf t Average

Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


58/64

Land Use Code ft., dwelling units, acres) % Size Trip Rates Unit Trips Generated


Manufacturing 1,000,000 30% 258 58 200 8% 53 184



Distribution 1,000,000 50% 235 59 176 8% 54 162


1,000,000 20% 257 42 215 2% 37 208



Totals 1,000,000 1.00 1,000,000 750 158 592 0 10 34 144 555


Final AverageCaptured TripsDist r ibution Draf t Average Reduction ReductionReduction

1/6/2006


Alternative B (aka Alt. 3)Weekday, Peak Hour of Adjacent Street Traffic, One Hour Between 4 and 6 p.m. 0% 0%



ft., dwelling units, acres)

Weighting

%

Weighted


Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


59/64

g ) p p


Manufacturing 1,000,000 25% 215 48 167 8% 44 154



Distribution 1,000,000 25% 118 29 88 8% 27 81


1,000,000 50% 643 104 539 2% 91 518



Totals 1,000,000 1.00 1,000,000 975 181 794 0 8 30 163 753


gp pg

1/6/2006


Alternative B (aka Alt. 3) with Reduced Office SpaceWeekday, Peak Hour of Adjacent Street Traffic, One Hour Between 4 and 6 p.m. 0% 0%




Weighting

%

Weighted


Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


60/64


Manufacturing 1,000,000 25% 215 48 167 8% 44 154



Distribution 1,000,000 25% 118 29 88 8% 27 81


1,000,000 50% 514 83 431 2% 73 414



Totals 1,000,000 1.00 900,000 847 160 686 0 8 28 144 649


1/6/2006


Preliminary Alternative 1Weekday Weekday 0% 0%




Weighting

%

Weighted

Size Trip Rates Unit Trips Generated


Final Average

Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


61/64


Manufacturing 1,000,000 50% 2,698 1,349 1,349 8% 1,241 1,241

Light Industrial (110) 0.25 250,000 6.97 1000 sf area 1,743 50% 50% 871 871 0 0 70 70 802 802 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho


Distribution 1,000,000 25% 1,240 620 620 8% 5 70 5 70

Warehousing (150) 0.25 250,000 4.96 1000 sf area 1,240 50% 50% 620 620 0 0 50 50 570 570 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho

1,000,000 25% 2,390 1,195 1,195 2% 1,134 1,134

General Office (710) 0.13 125,000 11.01 1000 sf area 1,376 50% 50% 688 688 38 38 0 0 13 13 637 637 Peak hour of generator coincided with adjacent traffic.

Research and Development (760) 0.13 125,000 8.11 1000 sf area 1,014 50% 50% 507 507 0 0 10 10 497 497 Truck trips are 0.4-4.0% of weekday traffic and peak hour of generator coincided with adjacen

Totals 1,000,000 1.00 1,000,000 6,328 3,164 3,164 0 181 181 2,945 2,945


1/6/2006


Alternative A (aka Alt. 2)Weekday Weekday 0% 0%




Weighting

%

Weighted



Final Average

Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


62/64


Manufacturing 1,000,000 30% 1,619 809 809 8% 7 45 7 45

Light Industrial (110) 0.15 150,000 6.97 1000 sf area 1,046 50% 50% 523 523 0 0 42 42 481 481 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho


Distribution 1,000,000 50% 2,480 1,240 1,240 8% 1,141 1,141

Warehousing (150) 0.50 500,000 4.96 1000 sf area 2,480 50% 50% 1,240 1,240 0 0 99 99 1,141 1,141 Peak hour of generator coincided with adjacent traffic and shift workers may peak at other ho

1,000,000 20% 1,912 956 956 2% 9 07 9 07

General Office (710) 0.10 100,000 11.01 1000 sf area 1,101 50% 50% 551 551 31 31 0 0 10 10 510 510 Peak hour of generator coincided with adjacent traffic.


Totals 1,000,000 1.00 1,000,000 6,011 3,005 3,005 0 182 182 2,792 2,792


1/6/2006


Alternative B (aka Alt. 3)Weekday Weekday 0% 0%




Weighting

%

Weighted



Final Average

Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


63/64

g g g g g g g g g g g g g g g g

Manufacturing 1,000,000 25% 1,349 674 674 8% 6 20 6 20



Distribution 1,000,000 25% 1,240 620 620 8% 5 70 5 70


1,000,000 50% 4,780 2,390 2,390 2% 2,257 2,257

General Office (710) 0.25 250,000 11.01 1000 sf area 2,753 50% 50% 1,376 1,376 91 91 0 0 24 24 1,262 1,262 Peak hour of generator coincided with adjacent traffic.

Research and Development (760) 0.25 250,000 8.11 1000 sf area 2,028 50% 50% 1,014 1,014 0 0 19 19 995 995 Truck trips are 0.4-4.0% of weekday traffic and peak hour of generator coincided with adjacen

Totals 1,000,000 1.00 1,000,000 7,369 3,684 3,684 0 146 146 3,448 3,448


1/6/2006


Alternative B (aka Alt. 3) with Reduced Office SpaceWeekday 0% 0%




Weighting

%

Weighted



Final Average

Internally

Captured Trips

Directional


Light Rail

Reduction

Retail Passby

Reduction

Truck Traffic

Reduction


64/64

Manufacturing 1,000,000 25% 1,349 674 674 8% 6 20 6 20



Distribution 1,000,000 25% 1,240 620 620 8% 5 70 5 70


1,000,000 50% 3,824 1,912 1,912 2% 1,810 1,810

General Office (710) 0.25 200,000 11.01 1000 sf area 2,202 50% 50% 1,101 1,101 68 68 0 0 19 19 1,014 1,014 P eak hour of generator coincided with adjacent traffic.

Research and Development (760) 0.25 200,000 8.11 1000 sf area 1,622 50% 50% 811 811 0 0 15 15 796 796 Truck trips are 0.4-4.0% of weekday traffic and peak hour of generator coincided with adjacen

Totals 1,000,000 1.00 900,000 6,413 3,206 3,206 0 137 137 3,001 3,001


1/6/2006

Documents

DMCBP CMP Traffic Study