HomeMy WebLinkAboutInterlocal Agmt for Trans Imp Related to Muckleshoot Indian Tribe Casino Garage Mitigation
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Return Address: PACIFIC NY TIT INTERLOCA 48."
PAGEllt OF 817
Auburn City Clerk 12/13/211' 11:4.
KING COUNTY, YA
City of Auburn
25 West Main St.
Auburn, WA 98001
RECORDER'S COVER SHEET
Document Title(s) (or transactions contained therein): ~~W, - \N'?~~b - \~
Interlocal Agreement for Transportation Improvements ~~
Reference Number(s) of Documents assigned or released:
DAdditional reference #'8 on page of document
Grantor(s)/Borrower(s) (Last name first, then first name and initials) ~
Auburn, City of
Grantee/Assignee/Beneficiary: (Last name first) ~
1. Muckleshoot Indian Tribe Legal Description (abbreviated: i.e. lot, block, plat or section, township, range)
PER RCW 39.34
D Additional legal is on page of document.
Assessor's Property Tax Parcel/Account Number
N/A
o Assessor Tax # not yet assigned
Saio oocument(s) were flied for
record by Pacific Northwe8t Title as
aacornmodatiOn onty. It h8I not been
examiIed as to proper ex8CUllon...
aat:>>lIIaIfect upon title.
-'.' .".._"_._._.~_..+.-
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INTERLOCAL AGREEMENT
FOR TRANSPORTATION IMPROVEMENTS
RELATED TO MUCKLESHOOT INDIAN TRIBE
CASINO GARAGE MITIGATION
1. INTERRLOCAL AGREEMENT
" f\.,/
This Interlocal Agreement (Agreement) is made and entered into on the --t-,:::::day of
, 2004, by and between the City of Auburn, a municipal
co ratio of the State of Washington, hereinafter referred to as the "City," the
Muckleshoot Indian Tribe, a sovereign jurisdiction located within the State of
Washington, hereinafter referred to as "MIT," pursuant to the authority of Chapter
39.34 of the Revised Code of Washington.
2. PURPOSE
The purpose of this Agreement is to document the implementation of the
recommendations included in the Muckleshoot Casino Garage Traffic Impact Analysis
Study attached as Enclosure 1 and incorporated herein as a part of this agre:ement and
hereinafter referred to as the study.
3. RESPONSIBILITIES
A. The MIT agrees to perform the improvements recommended to lhe public
street system as set forth in the study recommendations at its own cost and
fully reimburse the City for all city costs incurred for improvements performed
by the City that are consistent with the reimbursement estimate provided to
MIT. The MIT also agrees to mark the garage exits so that traffic towards the
exit leading to Dogwood is deemphasized.
B. The addition of, and specific design of the c-curb recommendation to be
installed by the MIT, is subject to WSDOT approval. Should WSDOT fail to
approve the addition of the c-curb, MIT shall be relieved of all responsibility I
pertaining to this recommendation in the study. To obtain approval of the
scope of work agreed, the MIT Traffic Consultant's will prepar(~ a more
detailed conceptual plan in the fmal draft of the study to relate the on-site
traffic channelization plan to the street access control plan. Upon City and
WDOT approval of the submitted concept access control plan, the MIT agrees
to proceed by contract to install the access control facility (C- curb) in a
manner that is coordinated in time with the on-site traffic routing plan
illustrated in the attached Traffic Mitigation study. The MIT agrees to have its
contractor that performs the on-site work obtain a City construction permit
prior to proceeding to contract to install the public access control
improvements using the City's Construction Permit Process. The City agrees to
inspect the right of way improvements using its normal permit system. The
Page I
1
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City agrees to review and approve the MIT plans to the conformance with City
standards, coordinate with and obtain the WSDOT approval for the particular
proposed access control features and inspect the work of the MIT contractor
until satisfactory completion of the work.
C. The City agrees to use in-house staff and equipment to make: the signal
modifications recommended in the study and upon final compl<~tion of the
work will submit to the MIT a final bill consistent with the estimate provided
to MIT for the actual costs to include labor, equipment rental, materials, and
any subcontract work that maybe required to complete the scope of work.
Upon receipt of the City's letter of final billing the MIT agrees to pay the
amount due within 30 days.
4. INDEMNIFICATION
Each party shall indemnify and hold the other parties, and their agents, employees,
and/or officers, harmless from and shall process and defend at its own e:xpense any
and all claims, demands, suits, at law or equity, actions, penalties, losses, damages, or
costs, of whatsoever kind or nature, brought against the other parties arising out of, in
connection with, or incident to the indemnifying party's performance or failure to
perform any aspect of this Agreement; provided, however, that if such claims are
caused by or result from the concurrent negligence of two or more parties, their agents,
employees, and/or officers, this indemnity provision shall be valid and l~nforceable
only to the extent of the negligence of the indemnifying party; and provided further,
that nothing herein shall require the party to hold harmless or defend the other parties,
their agents, employees and/or officers from any claims arising from the sole
negligence of the other parties, their agents, employees, and/or officers. No liability
shall attach to the other parties by reason of entering into this Agreement except as
expressly provided herein.
5. COMPLIANCE WITH REGULATIONS AND LAWS
The parties shall comply with all applicable rules and regulations pertaining to them in
connection with the matters covered herein.
6. ASSIGNMENT
The parties shall not assign this Agreement or any interest, obligation or duty therein
without the express written consent of the other parties.
7. ATTORNEYS' FEES
Each party shall be responsible for its own attorney fees and costs.
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8. NOTICES
The Parties have designated formal points of contact and coordination for this
Agreement as shown below. All interagency correspondence outlined heTein, will be
sent through these designated contacts:
THE MUCKLESHOOT INDIAN TRIBE CITY OF AUBU~
Name: Steve Taylor Name: Dennis Dowdy
Title: Planning Director Title: Public Works Director
Address: 39015 - 172nd Avenue S.E. Address: City of Auburn
Auburn, W A 98092 25 West Main
Telephone: (253) 876-3329 Auburn, WA 98001-4998
FAX: (_) Phone:(253) 931-3023
FAX: (253 931-3053
9. NONDISCRIMINATION
Each party agrees that it will comply with pertinent statutes, Executive (hoders and
such rules as are promulgated to assure that no person shall, on the grounds of race,
creed, color, national origin, sex, age, or the presence of any sensory, mental or
physical handicap be discriminated against or receive discriminatory tre:atment by
reason thereof.
10. MISCELLANEOUS
A. All of the covenants, conditions and agreements in this Agreement shall extend
to and bind the legal successors and assigns of the parties hereto.
B. This Agreement shall be deemed to be made and construed in accord.ance with
the laws of the State of Washington.
C. The captions in this Agreement are for convenience only and do not in any way
limit or amplify the provisions of this Agreement.
D. The duration of this Agreement shall be for the period of time it reasonably
takes for the performances by the parties as completed herein.
E. The oversight and administration of the Agreement shall be by the respective
named representatives identified in Section 8 hereof, or their designees.
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'-"~-
F. No provision of this Agreement shall relieve either party of its public agency
obligations and or responsibilities imposed by law.
G. If any term or provision of this Agreement or the application the:reof to any
person or circumstance shall, to any extent, be held to be invalid or
unenforceable by a final decision of any court having jurisdiction on the
matter, the remainder of this Agreement or the application of such term or
provision to persons or circumstances other than those as to which it is held
invalid or unenforceable shall not be affected thereby and shall continue in full
force and effect, unless such court determines that such invalidity or
unenforceability materially interferes with or defeats the purposes hereof, at
which time the parties shall have the right to terminate the Agreement.
H. No modifications or amendments of this Agreement shall be valid or effective 0
unless evidenced by an agreement in writing signed by all Parties.
11. TERMINATION OF AGREEMENT
By signing this Agreement, the City and MIT agree to the terms and commitments
outlined above. This Agreement may be modified at any time upon the mutual
agreement of all Parties.
MUCKLESHOOT INDIAN TRIBE CITY~
-II
By: U-Q. ... ~ ---:::>
.-
/ . - ... Peter B. Lewis, Mayor
Its: t'~,uw>'~
Attest: I~/A Attest: ,d)~~ ~
City Clerk
Approved as to form: ~X
Auburn City Attorney ........._______.
Page 4
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11effron
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MEMORANDUM
Date: June 4, 2004
To: Steve Taylor, Muckleshoot Indian Tribe
CC: Dennis Dowdy, City of Auburn Public Works Director
Paul Krauss, City of Auburn Planning & Community Development Director
Laura Philpot, C~y of Auburn Traffic Engineer
From: Marni C. Heffron, P.E., P.T.OE 0
Subject: Muckleshoot Casino Parking Garage
Additional Traffic Analysis
Per the request of the City of Auburn, Heffron Transportation has performed additional analysis for the
Muckleshoot casino parking garage. This additional analysis includes:
. Review of prior traffic analyses prepared by Transportation Solutions, Inc. (TSI),
. Evaluation of traffic operations at the two signalized intersections adjacent to the site on Auburn Way S,
. Review of internal traffic flow and proposed site circulation modifications,
. Evaluation of traffic accidents along Auburn Way S adjacent to the site, and
. Recommendations for additional mitigation measures.
Summary of Findings
Heffron Transportation reviewed past analyses prepared by TSI and found it to be consistent with standard
practices and acceptable. New analysis was performed by Heffron Transportation to assess traffic safety and
signal phasing needs at the adjacent intersections. This analysis determined that the eastbound left-turn
movement at the Auburn Way SlDogwood Street SE intersection should be provided protected-only (no
permitted turns) signal phase.
In addition, a sensitivity analysis was performed, which determined that traffic operations at the Auburn Way
SlDogwood Street SE intersection would not degrade to an unacceptable level of service even if all of the
casino traffic were to enter and exit the site via Dogwood Street SE.
Based on new analysis presented herein, the following mitigation measures are recommended.
6544 NE 61st Street, Seattle, WA 98115 Phone: (206) 523.3939 Fax: (206) 523-4949
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Muckleshoot Casino Parking Garage heffr()n
Additional Traffic Analysis
June 4, 2004 t ran S ) () r t ,I 'l Ion. ) 11 C
Page 2 of II
. Provide a protected-only left-turn signal phase for eastbound-to-northbound traflk at the
Auburn Way S/Dogwood Street SE intersection. The volume of traffic making this left turn
was high enough before the parking garage was constructed to warrant this change. The
protected-only phase should be set up as a "lagging" phase.
. Extend C-curb on Auburn Way S through the eastern site driveway adjacent to the bingo hall.
This C-curb will help enforce the right-turn-only restrictions at this eastern site driveway
intersection.
. Install sign age in the garage that directs motorists to exit through the main parking lot to
Riverwalk Drive SE. Provide only secondary signage at the back exit via Dogwood Street SE.
Review of Prior Traffic Analysis
A traffic impact analysis was perfonned for this site by Transportation Solutions, Inc. (TSI). Heffron
Transportation reviewed two documents: Muckleshoot Indian Casino Parking Garage Traffic Study (November
25,2003) and Transportation Comment Response/or Muckleshoot Casino Parking Garage (December 16,
2003). In addition, Heffron Transportation obtained and reviewed detailed trip generation calculations and the
Synchro traffic operations models from TSI.
Heffron Transportation concurs with the trip generation estimates presented in the traffic study. Because the
project was not increasing the size of the casino, trip generation to and from the site is not expected to change-
it would simply redistribute traffic from one area of the site to another.
PM peak hour traffic counts at the existing driveways were reviewed to evaluate current arrival and departure
travel patterns for the site. This infonnation was not disclosed in the TSI traffic study. The existing trip
distribution pattern is shown on Figure l.This shows that 80% of the site's PM peak hour traffic anives from
the west on Auburn Way S or from the south on Riverwalk Drive SE. Traffic leaving the site to the west and
south accounts for 75% ofthe total departing traffic. The trip distribution pattern is consistent with Muckleshoot
Tribe infonnation about the market area for the casino. The vast majority of their patrons are from areas west of
the site.
Heffron Transportation agrees with TSI's conclusions that trips using Dogwood Street SE north onhe site are
not likely to change with the new garage. An occasional patron unfamiliar with the area my drive through this
neighborhood once, but will not do it a second time.
Heffron Transportation also agrees with TSI's position that most drivers would enter the site at the main driveway
(Driveway A in the TSI report opposite Riverwalk Drive). This driveway is well marked with the casino's sign,
and is located at the first signalized intersection along this segment of roadway when arriving from the west. As
mentioned previously, the vast majority (80%) of the casino's patrons arrive from this direction. When patrons
leave the site, Heffron Transportation agrees that most first-time visitors would exit using the same route used to
enter. Those more familiar with the site could short-cut directly to Auburn Way S and turn right at the
unsignalized site driveway (Driveway C). Unless extreme congestion occurs at these two driveways, it is unlikely
that many westbound patrons would try to exit using Dogwood Street SE since it would require out-of-direction
travel and travel through a second signalized intersection.
About 10% of the casino's traffic arrives from and departs to the east. This traffic is the most likely to use
Dogwood Street SE. When entering the site, some of the traffic from the east will continue to use driveways
along Auburn Way S because there will be no restriction on these right-turn movements. When exiting,
however, almost all traffic would likely use Dogwood Street SE because left-turns are prohibited at Ithe
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Muckleshoot Casino Parking Garage he .f.fr on
Additional Traffic Analysis . .
June 4, 2004 t r <I n s ) 0 r t ,I t 11t..._ ._
Page 3 of 11
unsignalized driveways on Auburn Way S, and exiting through the main driveway would require out-of-
direction travel.
For the reasons listed above, TSI's assumption that 30% of the traffic using Dogwood Street SE to exit the site
is conservatively high. However, Heffron Transportation performed additional analysis to show how both the
Auburn Way S/Dogwood Street SE and Auburn Way S/Riverwalk Drive SE/Driveway A interse(;tions would
operate if required to accommodate more traffic than evaluated in the TSI report. That analysis is presented later
in this memorandum.
Additional Traffic Data
Additional traffic data were obtained for this analysis. Specifically, seven-day traffic counts at Auburn Way S
and Riverwalk Drive SE performed for the City of Auburn beginning the week of November 16,2003 were
obtained. These counts were then compiled to show the peaking characteristics on Auburn Way S. Existing
counts of the casino performed for TSI were also compiled to show how the peak hour ofthe casilllo relates to the
peak hour on the local street. Figures 2 and 3 below show traffic volumes on Auburn Way S and at the casino for
a weekday and Saturday, respectively. It should be noted that the Sunday traffic volume pattern were very
similar to Saturday, except that there was no late peak for casino traffic.
Figure 2. Weekday Traffic Volume Comparison
3,000 ........... ..... ........................"".. .........._..."...........".""..................................._..... ................... ."..............................................._................................. ..........."..._.. ............ ........ ..... .........".. ... ......".................
f -Weekday Traffic Volumes on Aubum Way
r - - Casino Traffic on Monday. Thursday
2,500 .--.-.-- - - Casino Traffic on a Friday
2,000 ... _
j
j 1.500 " .-. --' ~
f .. .. ~
1.000 -._...~--_. .... .,. .,
,,:..- ...'.."".......-----
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- - ~
500
.. /'
"......... ~...__ ...- fI"
o
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
---_._._---~..,.-._-
_..__._..__~,_._____..M..__.__ . _._..~__
Muckleshoot Casino Parking Garage heffr()n.
Additional Traffic Analysis
June 4, 2004 t ran !:> ) 0 r t .1 1 Oil, 111-":.
Page 4 of 11
Figure 3. Saturday Traffic Volume Comparison
3000 ......... .......... ........... ......... ........ ........... ..... .............."...........
-Saturday Traffic Volumes on Auburn Way
2500 - - Casino Traffic on a Saturday
2000
~
~
j 1500
f =\-
1000 -., - -
- # . #
# ~ #
500 '"
0
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ i~ ~ ~
8 ~ ~ ~ a 8 8 8 8 8 8 8 8 8 ~ a 8 8 8 a a B 8 8
(:! " Ilj ell r:.: ci:i Iri $1 ~ (:! ~ l'l .., ill ell '" .. 10 $1 ~
The volume comparisons above show that TSl's analysis of the afternoon commuter peak hour is when traffic
volume in the corridor is the highest. It is also when traffic operations will be the worst. Therefore, TSl's
analysis adequately reflected the worst-case conditions for the site. However, Heffron Transportation did
perform additional analysis of the 10:00 to II :00 P.M. Friday night peak period when casino traffic is highest.
This analysis is presented later in this report.
Accident Analysis
Accident data were provided by the City of Auburn for the four-year period between January 1,2000 and
December 31, 2003. These data extended from Elm Street SE east of the site to M Street SE. Accident data
were compiled for the intersections immediately adjacent to the site to show types of accidents and the number
of accidents per year. The accident data are summarized in Table I.
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Muckleshoot Casino Parking Garage heffron
Additional Traffic Analysis
June 4, 2004 t ran s ) 0 r t ,I t .~._._
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Table 1. Study Area Accident Summary (January 1, 2000 - December 31,2003)
TVDe of Accident ITotals for Four Years) AGcidents bv Year
Rear- Side- Left Right Pedl
Intersection or Roadway Segment End Swioe Turn Anole Bike Other 2000 2001 2002 2003 Total
Auburn Way S/Dogwood Street SE 8 1 3 3 4 4 4 9 5 5 23
Auburn Way S/Arco Driveways 2 1 2 1 0 0 1 1 2 2 6
Auburn Way/East Bingo Hall Dwy 0 0 0 0 0 0 0 0 0 0 0
Auburn WaylWest Bingo Hall Dwy 0 0 0 1 0 0 0 0 0 1 1
Auburn WavlRiverwalk Drive 12 5 10 12 1 1 12 10 13 6 41
Source: City of Auburn, 2004.
The following summarizes some of the key findings in the review of accident data:
Auburn Way S/Dogwood Street SE
. Rear-end accidents were the type that occurred most frequently. Four involved eastbound
vehicles, three involved westbound vehicles, and one involved northbound vehicles. None
of the rear-end collisions involved southbound vehicles on Dogwood Street SE.
. All three of the left-turning accidents involved vehicles turning from eastbound Auburn
Way S to northbound Dogwood Street SE. This movement is currently controlled as a
protected-permissive signal phase, and it is likely that these accidents involved vehicles
turning on the permissive phase.
. There were a high number of pedestrian-related accidents at this intersection. One of the
four accidents resulted in a fatality, which was the only fatality at the intem~ction for the
study period. It appears from the City's data that many of these accidents involved
westbound vehicles on Auburn Way S; however, actual accident records would need to
be obtained to confirm this. The data do not provide enough information to attribute a
specific cause to the pedestrian accidents.
Auburn Way S1Riverwalk Drive SE
. About 30% of the accidents were rear-end collisions. Five involved westbound vehicles,
four involved eastbound vehicles, two involved northbound vehicles, and one involved
southbound vehicles exiting the casino site.
. About 30% of the accidents were right-angle collisions. Seven of the twelve accidents
involved vehicles exiting the casino site.
. Ten accidents involved left-turning vehicles colliding with oncoming through traffic. Half
ofthese (5) involved vehicles turning left from westbound Auburn Way S to Riverwalk
Drive SE. Two involved vehicles turning left into the casino site and two involved
vehicles turning left out of the casino site. Both the eastbound and westbound left-turn
movements at this intersection are already protected.
Auburn Way S/Casino Driveways
. There is record of only one accident involving vehicles turning to or from the: two unsignalized
casino driveways located between Riverwalk Drive SE and Dogwood Street SE. This was a
right-angle accident.
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Muckleshoot Casino Parking Garage heffron
Additional Traffic Analysis
June 4, 2004 t ran s ) 0 t t .1 "t L._.__
Page 6 of 1 1
As described in the following section, a signal phasing modification is recommended at the Auburn Way
S/Dogwood Street SE intersection to provide a lagging protected-only left-turn phase for eastbound to northbound
left-turns. This modification would likely improve safety conditions for this movement. These signal phasing
changes may also improve safety for pedestrians crossing Auburn Way S at this location by forcing westbound
traffic to stop well in advance of the east-west pedestrian phase. The accident data do not reveal fmy other trends that
may be correctable by changes in traffic signal phasing or lane geometry.
Signal Phasing Analysis
The City of Auburn requested analysis of signal phasing at both the Auburn Way SlRiverwalk Drive SE/Casino
Drive intersection and Auburn Way S/Dogwood Street SE intersection. Both intersections now halve some
movements with "permissive left-turn" phasing which requires left-turning vehicles to yield to oncoming traffic.
At the Riverwalk Drive SE intersection, left turns from Auburn Way S are protected (meaning motorists receive
a green arrow, and do not need to yield to oncoming traffic). Left turns from Riverwalk Drive SE, however, are
permissive. At Dogwood Street SE, the eastbound left-turn movement has a short protected phase (green
arrow), followed by permissive phasing in which both eastbound and westbound left turns must yield to
oncoming traffic. This is called "protected-permissive" phasing. The northbound and southbound left-turn
movements from Dogwood Street SE are permissive.
Analysis was performed to determine if some of the permissive left-turn phases should be changed to protected
phases. Guidelines from the Traffic Control Devices Handbook, 2001 (Institute of Transportation Engineers)
was used for this analysis. Applicable guidelines in the book suggest that a separate left-turn phas~~ be
considered based on:
.1. Traffic Volume:
a. When the number of left turns multiplied by the opposing conflicting volume in the peak hour
exceeds 100,000 on a four-lane street, or exceeds 50,000 on a two-lane street.
b. When the left-turn peak-hour volume is more than 90 vehicles or more than 50 vehicles on
streets with through traffic speeds over 45 mph.
2. Delay:
a. When left-turn delay is more than 2.0 vehicle hours during the peak hour on a critical
approach providing there are at least two left turns per cycle during the peak hour and average
delay per left-turning vehicle exceeds 35 seconds.
3. Accidents - Number of left-turn accidents:
a. When four accidents occur in I year or 6 accidents occur in 2 years on one approach.
b. When six accidents occur in I year or 10 accidents occur in 2 years on both approaches.
The permissive left-turn movements at the two intersections were evaluated using the above guidelines. Volume
and delay criteria were measured for conditions with the new parking garage open. Accident data were based on
the accident history from the past four years presented previously. The results are summarized in Table 2.
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Muckleshoot Casino Parking Garage heffron
Additional Traffic Analysis
June 4, 2004 t ran s ) 0 r t .1 t .c~)tl, ' r 1 (~.
Page 7 of II
Table 2. Protected Left-Turn Phasing Guidelines
Movement Meets or Exceeds IrE Guidelines
Volume Delay Accidents
Auburn Way S/Riverwalk Drive SE - Northbound & Southbound Left No No No
Auburn Way S/Dogwood Street SE - Eastbound Left Turn Yes No No
Auburn Way S/DoQwood Street SE - Northbound & Southbound Left No No No
Source: Evaluated using guidelines from the Traffic Control Devices Handbook, 2001 (Institute of Transportation Engineers).
As shown above, the eastbound-to-northbound left-turn movement would exceed the volume crit~:ria of more
than 90 vehicles during the peak hour. This volume is already exceeded and would be higher onc~: the parking
garage is opened. Therefore, it is recommended that this movement be changed from protected-pennissive
phasing to protected-only phasing. A protected phase at the end of the eastbound through cycle (also called a
lagging phase) is recommended for the eastbound-to-northbound left-turn movement. This requir~:s that
westbound traffic be stopped before the protected phase begins. As previously mentioned, a lagging phase may
also improve safety for pedestrians who cross Auburn Way S in the afternoon because westbound traffic would
be stopped well in advance of the east-west pedestrian phase. It appears that all of the pedestrian accidents at
this intersection involved westbound vehicles. The westbound-to-southbound left-turn movement does not meet
any of the criteria and could remain as pennissive phase during the PM peak hour.
Sensitivity Analysis
The City of Auburn and TSI did not agree as to the percentage of traffic that may use Dogwood Street SE to
access the new parking garage. Of particular concern is the number of vehicles that could travel through the
Auburn Way S/Dogwood Street SE intersection, and how the mitigation needed for that intersection could
change if the volume of traffic using Dogwood Street SE was higher than assumed. To address this concern, a
sensitivity analysis was perfonned with a range of casino traffic using the Auburn Way S/Dogwood Street SE
intersection. The distribution pattern shown previously on Figure I was used for this analysis. As shown, about
10% of the site traffic now travels on Dogwood Street SE north of the garage (to/from the residential
neighborhood located north), and do not pass through the Auburn Way S/Dogwood Street SE intersection. This
percentage is not expected to change. Another 10% is destined to and from the eas.t on Auburn Way S, and all
of this traffic is expected to turn to and from Dogwood Street SE. What may vary is the amount oflraffic
arriving and departing to the west.
Weekday PM peak hour level of service analyses for the Auburn Way S/Dogwood Street SE intersl:ction were
perfonned for a range of casino traffic conditions. The amount of casino traffic arriving and departing the site
through this intersections was assumed to range from 10% to 60%. The lower end (10%) represents a condition
where only traffic to and from the east passes through this intersection. The upper end (60%) represents a
condition where two-thirds of the traffic arriving from or departing to the south and west (50% of aU site traffic)
would access the site through Dogwood Street SE instead of Riverwalk Drive SE. The level of service analysis
was performed assuming the protected-lagging left-turn phase on eastbound Auburn Way S described earlier.
For this reason, level-of-service results may not match prior TSI analysis, but better represent the anticipated
intersection operations. The level of service calculations were perfonned in increments with 10% additional
traffic to and from the west added until a total of 60% of the site traffic would pass through this intersection.
The results are illustrated in Figure 4.
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Muckleshoot Casino Parking Garage he. f')f"I' .""0' n.
Additional Traffic Analysis
June 4, 2004 t ran s ) 0 r tat I!~._li-
Page 8 of II
Figure 4. Sensitivity Analysis for Auburn Way S/Dogwood Street SE Intersection
30.0 ,------_. ---.-. I
;
;
. i
! LOSC I
~.O J
; ~~
! ~~ ~ I
:B 20.0 ' Intersection Delay During Commuter PM Peak Hour ------------.. ~ ____ ~ i
J! ___-- --t
8. I LOS B ~ ~ ~ _ --.&r- - I
~ 15.0 : ....... - _ .
i _- --w- !
i ---- -- i
; -- ~ I
~.-- -ar--- i
! 10.04r- - - \ I
! Intersection Delay During Casino Peak Hour (10 - 11 PM) i
~ I
5.0 I I
. .
, !
; l
: !
~o I ,
10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60%
Percent Casino Traffic Through Intersection
Note: Traffic 8ITiving from and dep8l1ing to the west was increased to determine the level of service values above. At tile
bottom end of the range (10%), only traffic 8ITiving from and departing to the east (towards Enumclaw) was assumed to
pass through the intersection. The top range (60%), assumes that 50% of the total site's traffic would 8frive from and
depart to the west through the Auburn Way S1Dogwood Street SE intersection.
The analysis shows that the intersection would continue to operate below LOS C conditions even if 60% of the
casino traffic were to enter/exit this location during the commuter PM peak hour. Even if 100% of the casino
traffic were to enter and exit the site through this intersection, it would continue to operate at LOS C or better.
The reason so much traffic can be added to this intersection with very little degradation in operations is that the
peak left-turn movement onto Dogwood Street SE toward the garage would be in the same direction as the peak
commuter flow (eastbound). Additional time for the eastbound left-turn phase can be added without causing
further delay to the eastbound through movement.
Additional analysis was performed to show how the intersection would operate when casino traffic iis the
highest, which occurs between 10:00 and 11 :00 P.M. During this time period, the casino generates almost twice
as much traffic as it does during the commuter PM peak hour. However, background traffic volumes on Auburn
Way S between 10:00 and 11:00 P.M. are about 40% of the commuter PM peak hour volumes. The sensitivity
analysis for this condition was also shown on Figure 4. It shows that the intersection would operate at LOS B or
better even if 60% of the casino traffic were to enter and exit the site through Dogwood Street SE.
The above analyses demonstrate that no further mitigation would be required for the Auburn Way SlDogwood
Street SE intersection. The eastbound-to-northbound protected left-turn phase recommended previously would
accommodate any shift in traffic created by the casino parking garage.
~_. '_'___'~'. '.___n.__._._". " __._,,__._._ ___ _ __ __~~ ____ _ _
Muckleshoot Casino Parking Garage heffron.
Additional Traffic Analysis
June 4, 2004 t r .l f) S ) 0 r t .1 1. .._._~
Page 9 of II
Site Plan Revisions
The Muckleshoot Tribe has changed its site plan from the previous site plan submitted to the City of Auburn.
Changes include:
. Creation of an east-west internal access road between the main entrance on Riverwalk Drive
SE and the parking garage that has no parking along it. This drive aisle will provide for
unimpeded entrance and exit to the garage.
. Creation oftwo northbound (inbound) lanes between the east-west internal aCCllSS road and
the garage to accommodate traffic arriving from Riverwalk Drive SE and the driveway
located east of the bingo hall. Northbound traffic on the bingo hall driveway would be
controlled by a stop sign where these two roadways intersect.
. Reconfiguration of the handicap parking area nearest the family entrance to the casino to
create a secondary access road between the passenger drop-off area and the garage entrance
that is 32-feet wide.
. Addition of a pedestrian walkway between the bingo hall and the casino.
. Creation of a "speed table" across the drive aisle immediately adjacent to the family entrance
to the casino.
A draft site plan reflecting these revisions is shown below on Figure 5.
Figure 5. DRAFT Site Plan with Revised Access Drives
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Muckleshoot Casino Parking Garage heffron
Additional Traffic Analysis
June 4, 2004 trans Jorta"l () n, tll~:
Page 10 of II
Although the accident data obtained from the City of Auburn did not reveal any safety issues at e:ither of the
casino's unsignalized driveways on Auburn Way S, the new parking garage and site reconfiguration could
increase traffic using the driveway east of the bingo hall. This driveway is currently signed for "Right Turn
Only;" however, there is no physical constraint to prevent drivers from making a left turn. To help enforce the
right-turn-only restriction, it is recommended that a C-curb be extended across the center turn lane to prevent
exiting left-turn movements. Schematic design attributes ofthis C-curb are described below.
Recommended Mitigation Measures
Three measures are recommended to accommodate the shift in traffic associated with the new casino parking
garage. These are:
. Provide a protected-only left-turn signal phase for the eastbound-to-northbound movement at
the Auburn Way S/Dogwood Street SE intersection. The volume of traffic making this left turn
was high enough before the parking garage was constructed to warrant this change. The
protected-only phase should be set up as a "lagging" phase.
. Extend C-curb on Auburn Way S in front ofthe eastern site driveway adjacent to the bingo
hall. C-curb currently exists between Riverwalk Drive and the western Bingo Hall Driveway,
and between Dogwood Street and the Arco Station driveway. It is recommended that the C-
curb be extended from Riverwalk drive through the east Bingo Hall driveway in a manner that
would prohibit left-turns exiting the site, but still allow left turns to enter the site. Allowing the
left-turn entrance would reduce potential impacts to Dogwood Street. A schematlic drawing of
this C-curb is shown below. This drawing depicts a break in the C-curb at the Areo driveway to
allow left turn movements at this location. The City of Auburn could extend the C-curb across
this driveway as part of this project or at sometime in the future.
Figure 6. Schematic Drawing of Auburn Way Channelization
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Muckleshoot Casino Parking Garage heffron
Additional Traffic Analysis
June 4, 2004 t ran!~ ) 0 t t " l '. () Il, I tl ,;
Page 11 of II
. Install signage in the garage that directs motorists to exit through the main parking lot. Provide only
secondary signage at the back exit via Dogwood Street SE.
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Attachments
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