YHS Access OptionsDRAFT
MEMORANDUM
Date: March 1, 2004
To: Erling (Rocky) Birkland, Yelm Schools
John Erickson, Erickson McGovern Architects
From: Marni C. Heffron, P.E., P.T.O.E.
Subject: Yelm High School
Access Options
This memorandum presents additional information and analysis for the Yelm High School access driveways. It
presents potential altema[ives chat could be considered to improve egress from the high school onto SR 510
(Yelm Avenue). No final recommendation is presented hl this memorandum. The information herein will be
used [o frame a discussion among Yelm Community Schools, the City of Yelm, and [he Washington State
Department ofTransportation (WSDOT). A final recommendation will 6e made after these parties can reach a
consensus about [he best traffic control at the school driveway.
Summary of Traffic Information
Information and analysis for the high school was presented in the Tro~c Impact Ana/ysis for Ye(m Conmmniry
Schools High Schoo( Remodel & New Junior High Schoo( (Heffron Transportation, Inc., December 16, 2003).
Key information used to establish design parameters and assess driveway operations are summarized in Table I
below for convenience. New information regarding the functional classification of SR 510 and physical site
dimensions is also provided.
Table 1. Traffic Information related to Yelm High School Driveway
PARAMETER DATA
Highway Information
Highway classification of SR 510+ Class 4 fiom Yelm City Limits (milepost 14.41) to Cullens SUeet (mp 15.20). A
"balance between mobility and access' is tlefined far this highway class.
Class 5 from Cullens Street to Junction of SR 507 (mp 15.67). The definition
for this class states that "access needs may have priority over mobility needs.'
Site frontage along SR 510 fi00 feel
~
Speed Limit 35 mph_ __ __ _ _
Traffic Volume Data
Average Daily Traffc A~ on SR 510 p 16,000 vehicles per day
Desi n Hourl Volumes DH See Fi ures 16 thru 18 in the Traffic Impact Anal sis
a Source HghwayAaess ManagementGuidebook, Olympic Regron, Apri17002.
b SourceWSDOTAnnual Traffic Repon.7007. COV0l well aljunc(ron wM SR WTpvjectetl tar year 2007.
Yelm High School Access Options
March I, 2004
Page 2 of 3
Site Access Issues
DRAFT
The TrajTc /mpac! Anal}~sis evaluated the cumulative impact of tvo 5thool district projects: the high school
remodel, and cons[me[ion of a new junior high school. The net effect of [here projects is that [raftic entering
and exiting the high school site is expected to decrease m the future since [he new junior high school would
allow the 9th grade to be removed from the school. However, a proposed reconfiguration ofthe hish school's
site driveways would concentrate more of this traffic a[ [he eastem driveway. The site currently operates with
two one-way driveways (all haff¢ enters at the westem driveway and exits at the eastem driveway). In the
furore, the eastem driveway would accommodate most of the entering and exiting traffic. Only buses and some
drop-off/pick-up trips would enter at the westem driveway. With [his change, entering and exiting traffic would
cross at [he eastem driveway, which would degrade the level of service compared to current conditions. The Iefl
[um exiting [he driveway is expected to operate at LOS F during rooming and afternoon peak hour conditions.
There are three potential measures [hat could be considered to improve operations at the eastern site driveway:
• Provide a two-way left-mm lane at the driveway.
• Provide alert-taro acceleration lane that is divided ftom westbound through naffic. Vehicles
would [um left across eastbound traffic into [he accelemlion lane, and then merge with
westbotmd traffic on SR 510.
• Install a haftlc signal (the driveway would meet Warrants 2 and 3 for a signal) .
The level of service for each of these elements was evaluated using the traffic volume information in the Traffic
Impact Analysis, and [he methodology in [he Highway Capacity Manua/. The Synchro 5.0 soRware was used
for [his analysis. Traffic operations for the two-way-left-taro lane use the median function in the calculation. To
emulate operations for a separated left-mm acceleration lane, through vehicles approaching from the west were
removed from [he calculation since they would no[ wnftict with the Iefl turn. The level of service results are
presented in Table 2.
Table 2. Level of Service at SR 510IHigh School Main Driveway -Year 2006'
WIh TWLTLs= Wth LeR-Turn ACCel Lanee Wilh Traffic Si nal
Intersections LOSa Dela • _LOS Dela LOS Dela
AM Peak Hour F >200.0 F 53.3 B 17.1
School PM Peak Hour F >200.0 D 26.6 B 19.1
Commuter PM Peak Hour F >200.0 D 32.8 B 14.8
a Levels a/service assume reduction in high school lran¢assoaateo wnn momng nn gravers om onne mnwi~~ro,iio, uyu auioma.
b Levels ofservice reponetl Por the wors(movemenl at(he intersection, which is the left taro exigrg the driveway
c M7-R = iwo~way-IeR-Wm lane
a LOS=Level of Service
e Delay=Average secondsoPoelayper vehicle.
As shown above, traffic exiting the site could experience intolerable delays ifonly a tvo-way-left-turn lane is
provided. Although a Icft-taro acceleration lane would improve traffic operations for vehicles esitine the site, it
would require design deviations from the WSDOT to fit in [he limited space between the eastem and western
driveways (there is about 520 between these driveways). Per WSDOT's Design Manun! euidelines, the
minimum Ienoth needed to provide adequate acceleration distance, tapers, and cleft-turn storage pocket at the
westem driveway is estimated to be about I .00 feet.. The total desireable length to fit all o(these features
would be about 1,200 feet A IcR-[urn acceleration lane would also rcyuire that the public street on the north
side o(SR 510 (Mountain View Road) be restricted to right-in/right-out movements. The trafic signal also has
some disadvanmees in that i[ .vould delay through [rafBc an SR 510, and would be about 0.3 miles from the
Yelm High School Access Options
March 1, 2004
Page 3 of 3
DRAFT
long term bypass connection proposed at Killion Road SE where another signal would eventually be located. A
summary of the advantages and disadvantages is presented below.
Table 3. Advantages and Disadvantages of High School Driveway Traffic Control Options
Lek~Turn Acceleration Lana
Disadvantages
not tlelay through traffic on SR 510 Would operate at LOS F during AM peak hour.
• 520-feet between high school driveways is too short
to provide full-length acceleration lane from eastern
tldveway (500 feet desired plus taper) and left turn
pocket to western high school driveway.
• Would require left-Wrn movements to and from
Mountain View Road to be prohibited.
• Would not facilitate pedestrian crossing of SR 510
Traffic Signal
ages Disadvantages
Would provide safest means of vehicle • Would delay through Vaffc on SR 510.
accesslegress Would he located 0.30 miles from poten0al future
Would allow full accesslegress from Mountain Mew Vaffic signal at Killion Road SE.
Road
City of Yelm officials requested further analysis of improvements a[ the SR 510/SR 507 intersection to
determine if [hose would benefit traffic operations at the high school driveway. Improvements at this
intersection located east of the high school would not improve the level of service at the high school driveway
since [he movement a[ issue is the left turn exiting the site (heading to the west, away from Yelm's main
intersection). Additionally, the combined effect ofboth [he high school and junior high school projects were
shown to reduce tratFc volumes aI [he SR 510/$R 507 intersection because of the reassignment of students
from [he existing high school and Yelm Middle School to the new junior high school. Because improvements at
[he SR 510/SR 507 intersection would not benefit the schools, and because the projects would reduce traffic al
this intersection, no mitigation a[ [his intersection is warranted.
MCH/mch
City of Yelm
Community Development Department
]05 Yelm Avenue West
P.O. Box 479
Yelm, WA 98597
NOTICE OF ASSUMPTION OF LEAD AGENCY ST US
Description of proposal: Yelm Community Schools Capital acilitie I pro4em nts
within the City of Yelm.
ProponenT.: Yelm Community Schools ,.: .
Location of Proposal: Within the corporate limits of th City of I ; Wa hington
Initial Lead Agency: Yelm Community Schools
New Lead Agency: City of Yelm
The initial lead agency concluded t t t ' .pro I wa no likely to ha sigriific nt
adverse impacts on the environ rit a cord' g its d ter inati n of n nsi ' icance
dated DAT
W ave reviewed th a vironm ntal ch ckli a d rela ed i fo ation. In our opinion,
a environ~tal imp ct state ent (EI ) is eq red on the roposal, because of the
owing impa~ts:
T affc i pacts
u are eing otifie th t we ssume the responsibility of lead agency under SEPA,
ludin the ty to pre area EIS on the proposal.
G ant B ,Director
C unity Development Department
Ci y of Yelm
105 Yelm Avenue West
P.O. Box 479
Yelm, WA 98597
(360)458-8408
gra ntb@ci.yelm.wa. us
(360) a59~9R35
(360) A58-31Jd FeiX
mww.ci.ya4rn.wn.ua
City of Yelm
Community Development Department
105 Yelm Avenue West
P.O. Box 979
Yelm, WA 98597
DETERMINATION OF SIGNIFICANCE
AND REQUEST FOR COMMENTS ON SCOPE OF EIS
Description of proposal Yelm Community Schools Capital Fa ' ies I overrY s
within the City of Yelm.
Proponent Yelm Community Schools
Location of proposal Within the corporate limits of the C ty of Yel , Waslii gton
Lead agency City of Yelm
EIS Required. The lead agency has determined s pro s I 's likel to h ve a
significant adverse impact on the environme . An"enviro me tal im act s atement
(EIS) is required under RCW 43.21 C.030 ( (c) a will b pr pare An a vironme to
checklist or other materials indicati i el env' on ental imp cts c n be eview at
our offices.
The I agency has i nti ied the owin are f r dis uss on i he EIS:
Tra Im acts
Sco ing. enci s, affe to tribe ,and ember of the public are invited to comment
on t o sco a of t o EIS Y u ma comm t alternatives, mitigation measures,
pro able s nific nt ad ers imp cts, and licenses or other approvals that may be
req fired. e m thod nd eadli a for giving us your comments is:
Gra II t Beck; Direct Date
Corrlmunity Dev opment Department
105 ~YeJm'Avenue West
P.O. ox 479
Yelm, WA 98597
(360)458-8408
g rantb@ci.yelm.wa. us
(360)159-3835
(3607 458-31~bf FAX
wmw.ce.y¢Ln.ma.us