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TIA TRAFFIC IMPACT ANAL YSIS SAFEWA Y STORE AND RETAIL CENTER YELM, WA MAY 6,1998 HEFFRON TRANSPORTATiON 4133 Interlake Avenue N Seattle, WA 98103 (206) 547-7170 TABLE OF CONTENTS MITIGATION APPENDIX 1 1 1 1 5 5 8 9 10 10 12 12 16 17 18 18 19 INTRODUCTION Project Description BACKGROUND CONDmONS Roadway Network Traffic Volumes Level of Service. Traffic Safety Transit and Non-Motorized Facilities PROJECT IMP ACTS Trip Generation Trip Distribution and Assignment Level of Service. Site Access Interim Vancil Road Conditions. Traffic Safety Transit and Non-Motorized Facilities FIGURES Figure 1. Site Vicinity Map Figure 2. Site Plan Figure 3 Existing (1997/98) Traffic Volumes - PM Peak Hour Figure 4 1999-Without-Project Traffic Volumes - PM Peak Hour Figure 5 Project Trip Distribution Pattern For New Trips Figure 6. Total PM Peak Hour Project Trip Assignment Figure 7 1999- With-Project Traffic Volumes - PM Peak Hour 3 4 6 7 13 14 15 TABLES Table 1. Level of Service Summary - Existing and 1999-Without-Project Conditions Table 2. Study Area Accident Summary (January 1, 1994 through December 31, 1996) Table 3 Trip Generation Summary - Total Driveway Trips Table 4 Trip Components Table 5 Level of Service Summary - Without- and With-Project Conditions Table 6 Site Access Level of Service Summary Table 7 Level of Service Summary - Interim Vancil Road Conditions with Existing Geometry 8 9 11 12 16 17 18 Yelm Safeway Store and Retail Center - Traffic Impact Analysis INTRODUCTION This report summarizes the transportation impact analysis for the proposed Safeway store and retail center to be located in the City ofYelm, Washington. The scope of work and study area for this analysis were developed with assistance from City ofYelm staff. The analysis evaluates the project's impact to off-site roadways and intersections as well as site access. Project Description Safeway is proposing to construct a new shopping center on the southwest comer of the Y elm Avenue (SR 507)/ Vancil Road intersection. The new shopping center would include a 56,232-sf supermarket and approximately 18,733 sf of retail space for a total of 74,965 sf. It is likely that the proposed project will be built in phases with the supermarket being built first The new shopping center would have four main access driveways: two on Vancil Road, and two on Yelm Avenue. An emergency access road would be constructed along the back (south) of the Safeway building and would have an emergency access driveway on Vancil Road. Approximately 418 parking spaces would be provided for the Safeway store, 461 spaces would be provided for the full shopping center Figure 1 shows the site locatio~ Figure 2 shows the site plan and site access driveway locations. BACKGROUND CONDITIONS This section of the report discusses the existing and future conditions that would exist without the proposed Safeway project. The impacts of the project are evaluated against these base conditions. The Safeway project is scheduled to be complete by the year 1999 Roadway Network The study area for this analysis was determined based on the proposed project's trip generation and trip distribution pattern (presented later in this report). The analysis determined that several roadways and intersections would be impacted by 20 or more peak-direction PM peak hour trips. This study focuses on the following key streets and intersections near the site: . SR 51 O/Solberg Street · SR 507/SR 510/lst StreetNelm Avenue · Yelm Avenue (SR 507)1103rd Street . Yelm AvenuelVancil Road . Yelm A venue!Plaza Drive · Yelm A venuelBald Hill Road The roadways included in the study area for this analysis are described in detail below SR 507/Yelm Avenue is a two-lane roadway that provides access through the City ofYelm. SR 507 approaches the City of Yelm from the southwest and makes a 90-degree turn to the southeast at its intersection with SR 510 and 1st Street. At this location, it becomes Yelm Avenue. The SR 507/SR 510/1st StreetNelm Avenue intersection is controlled by a traffic signal and has crosswalks equipped with pedestrian buttons and crossing signals. The posted speed limit on SR 507 southwest of SR 510 and 1st Street is 50 mph; the speed limit is reduced to 25mph approaching SR 510 HEFFRON TRANSPORT A nON -1- May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis Yelm Avenue, just east of the SR 507/SR 51O/1st StreetNelm Avenue intersection, is a two-lane roadway with parking and sidewalks on both sides of the street. The posted speed limit is 35mph from the SR 507/SR 510/1st StreetNelm Avenue intersection through the Plaza Drive intersection. East of the Plaza Drive intersection, the speed limit is reduced to 30 mph. Near the project site, there are three lanes (two in each direction and a center turn lane) as well as a bike lane on the north side of the street. The bike lane continues northwest on Yelm Avenue and then turns east to 103rd Street. There are bus stops serving Intercity Transit routes 92 and 94 along Yelm Avenue. Vancil Road is a two-lane, north-south roadway providing access between residential areas and Yelm Avenue. The Vancil RoadlYelm Avenue intersection is currently offset from the driveway serving the QFC retail center on the north side ofYelm Avenue. All four legs of the intersection (including the offset QFC driveway) are controlled by one traffic signal, with crosswalks, pedestrian buttons and pedestrian signals. The posted speed limit on Vancil Road is 25 mph. Plaza Drive is a two-lane, north-south roadway that connects 103rd Street and Yelm Avenue. Plaza Drive forms a "1'" intersection with SR 507 where traffic on Plaza Drive is controlled by a stop sign. There is currently a short acceleration lane for traffic turning left from Plaza Drive to Y elm Avenue. Bald Hill Road is a two-lane roadway that provides access from Y elm Avenue to the southwest. For most of its length, Bald Hill Road has a two-foot shoulder. However, at its intersection with Yelm Avenue, it has CUIb, gutter, and sidewalk. Bald Hill Road ends at this intersection and Creek Street continues north beyond the intersection. The Bald Hill RoadlYelm Avenue/Creek Street intersection is controlled by a traffic signal and has a crosswalk equipped with pedestrian buttons and signals. Southeast of the intersections with Y elm Avenue, Bald Hill Road has a posted speed limit of 50 mph. The speed limit is reduced as it approaches Y elm Avenue. 1st Street is a two-lane roadway that provides access from the SE. 507/SR 510Nelm Avenue intersection to the northeast The posted speed limit on 1st Street is 25 mph. 103rd Street is two-lane, east-west roadway with bike lanes on both sides of the street 103rd Street creates a "T' intersection with Yelm Avenue where traffic on 103rd Streetis controlled by a stop sign. At this intersection, 103rd widens to three lanes. SR 510 is a two-lane highway that provides access from the west to the City ofYelm. As SR 510 approaches the City of Yelm from the west, the speed limit is reduced from 35 mph to 25 mph. Solberg Street is a two-lane roadway providing access to downtown Yelm and residential areas northwest of the project site. Traffic on Solberg Street is controlled by stop signs at its intersection with SR 510 Crosswalks exist on the northeast and southwest legs of the Solberg StreetlSR 510 intersection. HEFFRON TRANSPORT A TlON - 2- Mav 6 1998 . N t<t.)t~ . .\~ - ~ " " fi T -. - -. 8 1 \'-- Sl \ \ Ii: ,. Ii t\ ~\ 'l' \ " ~.J!!'!~--'~--~ :~"~$-~ \ , ~\ \ "\ 30 4> Figure ~ flEFFR01"l 'iRA."NS pO R'i ^ 'it 0 'r' 4/61' SAfEWAY Vel"', WA S\1E V\C\N\n' M~P . N , -, '" ~ <.-~ ............ ':"~ ...... . ~,I,- ..~~ ---- ~::~- 1 ~ , . i J ~ ~ ~ \ \ \ \ \ \ \ \ ~l-\ \ \ \ '\ \ o . '" . r o .. :x . % f. U \ ~ [{i SAfEWA~ ye\r1\, VIA. figure 2 S\1E p\.AN tlEFFRON 'TRA."NSl?OR'T A.'T10t'l 416F. Yelm Safeway Store and Retail Center - Traffic Impact Analysis One key transportation improvement planned by the City of Yelm would directly affect the project study area and access. The City of Yelm is working to realign the Vancil Road/Y elm Avenue intersection. This realignment would create a four-leg, 90-degree intersection consisting of Vancil Road, the existing QFC access drive, and the two approaches ofYelm Avenue. This realignment is planned to be complete concurrently or shortly after the proposed Safeway project. Therefore, the future-with-project analysis considers traffic conditions with the realigned lane configuration. A separate interim analysis is also presented to evaluate the potential impacts to operations at the Vancil Road/Yelm Avenue intersection if the Safeway supermarket is completed prior to the realignment project. In addition, the City of Yelm's Six Year Improvement Program identifies core roadway improvements for three sections ofYelm Avenue: one from 4th Street to Clark Road, one from Plaza Drive to Five-Comers, and one from Yelm High School to 1st Street. Traffic Volumes The City of Yelm requires that project impacts be evaluated during weekday PM peak hour conditions. This is because the PM peak hour is the time when traffic volumes on vicinity streets are highest, congestion is most noticeable, and the proposed project would generate the largest number of trips. Existing PM peak hour traffic volumes in the project vicinity were compiled from counts taken in 1997 and 1998. Figure 3 shows the existing PM peak hour traffic volumes in the project study area. The proposed shopping center is expected to open in 1999 To determine the traffic conditions that would exist in the future without the proposed project, existing traffic volumes were increased using a 4% annual growth rate. This growth rate was provided by City of Yelm Transportation review staff. Traffic generated by the planned Prairie Plaza Shopping Center development (to be located just east of the Safeway project at Plaza Drive) was also added to the future traffic volumes to represent year 1999-without-project traffic conditions. Trip generation and distribution patterns from the traffic impact analysis prepared for the Prairie Plaza Shopping Center were used to determine this project's traffic impact Figure 4 shows 1999-without-project traffic volumes. Level of Service Level of service (LOS) is a qualitative measure used to characterize traffic operating conditions. Six letter designations, "A" through "F," are used to define the level of service. LOS A is the best and represents good traffic operations with little or no delay to motorists. LOS F is the worst and indicates poor traffic operations with long delays. Level of service is defined in terms of delay For unsignalized intersections, delay is based on the number of gaps in the major street traffic through which a vehicle can enter or pass through the major street. For signalized intersections, delay is dependent on a number of variables, including the cycle length, green-time ratio, and volume-to-capacity ratio for the lane group or approach in question. A complete description of level of service criteria for signalized and unsignalized intersections is included in the Appendix. Levels of service for the study area intersections were determined using procedures in the Highway Capacity Manual. Table 1 summarizes the existing and 1999-without-project levels of service. The future analysis for the Yelm Avenue!Vancil Road intersection assumes the proposed realignment by the City ofYelm. The conditions that would exist if this intersection is not realigned are presented later in the Interim Vancil Road Conditions section of this report. This table shows that all intersections would operate at LOS D or better (overall). However, turn movements from 103rd Street and Plaza Drive would be degraded to LOS F conditions due to the increase in background traffic and traffic from other planned developments. HEFFRON TRANSPORTATION - 5- May 6 1998 () !; '" ^ '" o < "> z n ;= '" o 109TH 2 .i!l 1-----1- 397............ 347. . N 103 RD 5T L7 +- 437 .-51 lIb 175 SAFEWAY Yelm, WA Figure 3 EXISTING (1997/98) TRAFFIC VOLUMES PM PEAK HOUR HEFFRON TRANSJPORTATnON .,l>98 . N 103 RD ST to- 485-' ~\\,.2.?$ '>."., ~ "<0__\\..;_.. &'. <'\~~~( '" 1'0 , ~ :>> z () ;= ~ 109TH 5 jlL L10 +-- 495 .-55 5 --.-.t l!2r 455 ---. 395. 210 SAFEWAY Yelm, WA Figure 4 1999 WITHOUT.PROJECT TRAFFIC VOLUMES PM PEAK HOUR HEFFRON TRANSPORTATiON 4/6roB Yelm Safeway Store and Retail Center - Traffic Impact Analysis Table 1 Level of Service Summary - Existing and 1999-Wlthout-Project Conditions Existing 1999-Without-Project Signalized Intersection LOS1 Delay2 v/e3 LOS Delay vIe SR 507/SR 510/Yelm Avenue/1st Street C 17.8 070 D 25.1 078 Yelm AvenueNaneil Road C 15.7 0.72 C 21.6 073 Yelm AvenuelBald Hill Road B 10.8 0.56 B 117 0.62 Unsignalized Intersection LOS Delay LOS Delay SR 510/ Solberg Street (overall) A 0.6 A 0.9 Northbound movements from Solberg Street C 15.0 C 19.3 Southbound movements from Solberg Street C 15.9 D 201 Eastbound left tum from Yelm Avenue A 3.5 A 3.8 Westbound left tum from Yelm Avenue B 5.2 B 5.8 Yelm Avenue/103rd Street (overall) A 0.5 A 07 Left tum from103rd Street D 29.0 F 46.7 Right tum from 103rd Street B 6.3 B 7.5 Left tum from Yelm Avenue B 5.1 B 6.0 Yelm AvenueIPlaza Drive (overall) A 0.1 A 3.5 T ums from Plaza Drive B 68 F 45.8 Left tum from Yelm Avenue A 4.7 B 6.0 1 Levefofservke 2. Average seconds of delay per vehicle. 3. Volume-to-capacity ratio. Traffic Safety Traffic accident records were obtained from the Washington State Department of Transportation (WSDOT) for six study area roadways and intersections from Solberg Street to Bald Hill Road. Three years of the most recent data available were evaluated to determine historical traffic safety conditions. The SR 510/Solberg Street intersection had no reported accidents during the study period. Table 2 swnmarizes the traffic accident data for the five other study area intersections. As shown, 53 accidents occurred at the five study area intersections during the three-year period. The largest number of accidents (30) occurred at the SR 510/SR 507/Yelm Avenue/1st Street intersection; nearly half of those accidents were rear-end accidents. This intersection of two state routes occurs in the City of Yelm with reduced speed limits (reduced on SR 510 approaching from the northwest, and reduced on SR 507 approaching from the southwest) The intersection is signalized and is the first signal for some distance for vehicles approaching Yelm from the west. The combination of the reduction in speed limits, the potentially unexpected traffic signal, and wet conditions (8 of 14 rear-end accidents occurred with a wet roadway surface) may all contribute to the higher rate of rear-end accidents. Additional advanced signs warning of reduced speed limits, and the traffic signal may help to reduce the occurrence of rear-end accidents. HEFFRON TRANSPORTATION -8- May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis Table 2. Study Area Accident Summary (January 1, 1994 through December 31, 1996) Rear- Head- left- Side- Intersection End On Turn AnQle Swipe Other Total Acc.Nr · SR 507/SR 510Nelm Ave/1st St 14 0 0 3 2 11 30 100 Yelm AvenueIBald Hill Rd. 2 0 2 6 0 1 11 3.7 Yelm AvenueNanciJ Road 3 0 0 2 0 2 7 2.3 Yelm AvenueIPlaza Drive 1 0 0 0 0 1 2 07 Yelm Avenuel103rd Street 0 0 -0 0 0 3 3 10 Acc./Yr = Average number of accidents per year Transit and Non-Motorized Facilities Intercity Transit provides bus transit service to the study area along Y elm Avenue with stops located just west of Vancil Road and a bus shelter on the north side ofYelm Avenue. One route (94) provides transit service between Yelm and Lacey and operates weekdays from 6.30 AM. until 7.30 P.M. on approximately one-hour headways. There is a queue bypass lane for westbound buses at the Vancil Road intersection. Buses can use the right-turn lane to directly access the far-side bus pullout just west of the QFC driveway A sidewalk and bikepath also exist along the north side of Y elm Avenue. HEFFRON TRANSPORT A TBON - 9- May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis PROJECT IMPACTS This section of the report describes the conditions that would exist with the proposed Safeway project. First, the total number of project trips generated by the proposed shopping center was determined. Project trips were then added to the 1999-without -project traffic volumes. Finally, level of service analysis was performed to determine the proposed project's impact on traffic operations in the study area. The following sections describe the methodology used to determine the proposed project's impact Trip Generation The trip generation for the proposed site was determined using a methodology that has been applied for over 30 Safeway stores in Washington and Alaska. The methodology is tailored for each site to account for site-specific conditions such as traffic volumes passing the site and the number and location of competitive stores. The methodology acknowledges that new supermarkets must "capture" customers who are currently shopping at other stores or who would drive by the site on a regular basis. The trip generation is separated into three components: . Pass-by Trips are trips that are already on the roadway network on the way to another destination. For example, a trip to the supermarket made on a trip home from work would be considered a pass-by trip . Diverted (Intercepted) Trips are trips that, if not made to this supermarket, would be made to another supermarket For example, this project is expected to "capture" a percentage of the customers who now shop at the QFC across the street. These customers would be "diverted" to the new Safeway store. . New (primary) Trips are single purpose trips genemted by the supermarket New trips are generally assumed to begin and end at home, although some new trips could originate at work or other locations. These three trip components make up the total driveway trip generation. The methodology used for this site determined the total driveway trips first This is done by applying national rates to the size of the facility Then the driveway trips are separated into the three components based on the characteristics of the study area. Each of these steps is described in the subsequent sections. Driveway Trip Generation A study, entitled Montgomery County Trip Generation Study (Douglas & Douglas, 1989), was conducted to examine the trip generating characteristics of shopping centers that include supermarkets. It concluded that shopping centers with supermarkets have higher trip generation rates than those without supermarkets. This study recommended that the trip generation for shopping centers with supermarkets be calculated uSing a combination of rates for both land uses. The methodology was applied for this study Trip generation was determined using rates for "Shopping Centers" (Land Use Code 820) and "Supermarkets" (Land Use Code 850) from Trip Generation (Institute of Transportation Engineers (ITE), 5th Edition, 1991). Supermarket trip rates were applied directly to proposed Safeway store. A per-square-foot trip generation rate was calculated for the other retail space using the total size of the shopping center, including the supermarket. This methodology results in a higher trip generation rate than would result by applying shopping center rates alone. Since the proposed retail portions are being developed specuIatively (Safeway does not currently know who the retail tenants will be) and because the "shopping center" rates inherently assume a broad mix of retail and restaurant uses; the specific use of each retail pad is not needed to calculate trip generation. Total driveway trips for the proposed shopping center are summarized in Table 3 The proposed project would genemte 8,560 driveway trips per day and 718 driveway tnps during the PM peak hour HEFFRON TRANSPORTATION - 10- May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis Table 3 Trip Generation Summary - Total Driveway Trips PM Peak Hour Trips Land Use Size (sf) Dailv Trios In Out Total Proposed Supennarket 1 56,232 7,060 295 283 578 Proposed Retail Stores2 18,733 1,500 70 70 140 Total 74,965 8,560 365 353 718 1. Trip generation rate from 'Supermarket" rates in ITE's Trip Generation (5th Edition, 1991 LU 850) 2 Trip rate calculated from "Shopping Center" rates in ITE's Trip GeneratiOn (LU 820) for total center size of 71,150-sf Trip Components As previously mentioned, there are three types of trips-new, pass-by, and diverted trips-which reflect the traffic impact characteristics of retail developments. The fraction of driveway trips that is attributed to each of the above components depends on the size, type, and location of the proposed project as well as the location of other similar facilities. The City of Yelm allows a traffic impact analysis to assume a maximum pass-by rate of 25%. Given that Yelm provides most of the services for residents who live east of the City, and that many of those residences are located a long distance away, it is reasonable to assume that many customers would shop on the way home from work or school since it would save time. Therefore, the maximum 25% pass-by trip rate was used for analysis of the supermarket component. For the small amount of retail space on the site, the pass-by rate was assumed to be 45%. This rate was based on the City ofYelm's Trip Generation Rate Default Values presented in its Concurrency Management Ordinance (15 40) The proposed Safeway store is also expected to attract customers from other grocery stores in the site vicinity, particularly the QFC across the street. For this analysis, the City of Yelm transportation review staff have determined that 10% of Safeway's customers would be diverted away from other grocery stores. The project's retail element was assumed to generate no diverted trips. The remaining 65% of Safeway's trips and 55% of the retail trips would be considered new to study area roadways and intersections. The proposed project would result in 5,415 new trips per day and 450 new trips during the PM peak hour. Table 4 summarizes the net increase in driveway trips and the trip components for the proposed project. HEFFRON TRANSPORT A THON - 11 - May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis Table 4 Trip Components PM Peak Hour Trips Trip Component Percent Trios Dailv Trips In Out Total Safeway Store 56,232 sf Pass-by Trips 25% 1,765 73 73 146 Diverted Trips 10% 705 30 28 58 New (Primary) Trips 65% 4.590 192 182 374 Total Safeway Trips 100% 7,060 295 283 578 Retail Stores 18,733 sf Pass-by Trips 45% 675 32 32 64 Diverted Trips 0% 0 0 0 0 New (Primary) Trips 55% 825 38 38 ~ Total Retail Trios 100% 1,500 70 70 140 Total Shopping Center 74,965 sf Pass-by Trips 29% 2,440 105 105 210 Diverted Trips 8% 705 30 28 58 New (Primary) Trips 63% 5.415 230 220 450 Total Trips 100% 8,560 365 353 718 Trip Distribution and Assignment A trip distribution pattern had been developed for a previously proposed development on the project site. The City of Yelm had approved this trip distribution pattern and stated that it was still reasonable for the proposed Safeway project. Figure 5 shows the trip distribution pattern. The new project trips were assigned to the roadway network based on this distribution pattern. This assignment was used to determine the study area for the traffic impact analysis. The diverted trips and pass-by trips were assigned separately from the primary trips since they would primarily affect operations at the site driveways. The pass-by trips were assigned based on the PM peak hour traffic on Yelm Avenue since pass-by trips are assumed to come from traffic passing the site. The diverted trips were assigned assuming they would be diverted from the QFC located directly across Yelm Avenue from the site. Figure 6 shows the total project trip assignment. The project trips were added to the I 999-without-project traffic volumes. The resulting 1999-with-project traffic volumes are shown on Figure 7 Level of Service Levels of service for all study area intersections were calculated using the year 1999-with-project traffic vol- umes. Table 5 shows the results of the analysis; levels of service for 1999-without-project conditions are shown for comparison. The analysis determined that all study area intersection would continue to operate at LOS D or better (overall) for with-project conditions. Analysis of the Yelm AvenuelVancil Road intersection assumed that the intersection would be realIgned with the QFC driveway as proposed by the City of Yelm. Under this condition, it was assumed that 85% of the left-turns from the site onto Yelm Avenue would occur at the Vancil Road signal. It should be noted that even if all left-turn traffic used the Vancil Road signal to access Yelm Avenue, the signal would still operate at LOS D The conditions that would exist if this intersection is not realigned are presented later in the Interim Vancil Road Conditions section of this report The level of service analysis also determined that some additional delay is expected for turns from Plaza Drive and 103rd Street because of the Safeway project. Side street turning movements from both intersections are expected to operate at WS F in 1999 with or without the Safeway project. Descriptions of the turn-lane channelization at the Yelm Avenue/Plaza Drive/Safeway Drive intersection are presented in the site access section of this report. HEFFRON TRANSPORT A TllON - 12- May 6, 1998 XX% = Percent Site Traffic 5% () s:: ;0 ^ ;0 o 2% .< ;po z o r :>J o 109TH ::%:<,~:w.~:;,*i<<<.:.:::::-,":::;:';; :':;':':,,,,:;:;;;.,.,.:;::i,, . N 2% 103 RD ST () :>J m m ^ (/) ..... 20% ;:: J~~ ~~ 16% SAFEWAY Yelm, WA Figure 5 PROJECT TRIP DISTRIBUTION PA TIERN FOR NEW TRIPS HEFFRON TRANSPORTATION 416'98 . N ~o (l'oft; ~ -'?~ 10.3 RD 5T 109TH 13 t .. 14 44 --+ 1 35. SAFEWAY Yelm, WA Figure 6 TOTAL PM PEAK HOUR PROJECT TRIP ASSIGNMENT HEFFRON TRANSPORTATi.ON 41li'96 . N 529... o DC ...j ...j ::E ,':: l': ~::: <:: )> z: () ;= ;;0 o 6'i'0 ''\~( " 1'0 109TH 5 .ill L10 +-541 r-- 55 5--+ 499~ 430. l!r 247 SAFEWAY Yelm, WA Figure 7 1999 WITH-PROJECT TRAFFIC VOLUMES PM PEAK HOUR HEFFRON TRANSPORTATION ./6198 Yelm Safeway Store and Retail Center - Traffic Impact Analysis Table 5 Level of Service Summary - Wlthout- and With-Project Conditions 1999-without-Project 1999-with-Project Signalized Intersection LOS1 Delay2 v/e3 LOS Delay vIe SR 507/SR 510Nelm Avenue/1st Street 0 25.1 0.78 0 31.5 0.84 Yelm AvenueNaneil Road (With Realignment) C 216 073 0 26.5 0.83 Yelm AvenuelBald Hill Road B 11.7 0.62 B 14.8 0.67 LOS Delay LOS Delay SR 5101 Solberg Street (overall) A 0.9 A 1.2 Northbound movements from Solberg Street C 19.3 0 211 Southbound movements from Solberg Street 0 20.1 0 274 Eastbound left tum from Yelm Avenue A 3.8 A 4.0 Westbound left tum from Yelm Avenue B 5.8 B 6.2 Yelm Avenue/103rd Street (overall) A 07 A 1.3 Left turn from 103rd Street F 46.7 F 87.5 Right tum from 103rd Street B 7.5 B 8.8 Left tum from Yelm Avenue B 60 B 7.2 Yelm Avenue)/P1aza Dr./Site Dwy (overall) A 3.5 B 9.5 Tums from Plaza Drive F 45.8 F 121.8 Left tum from Yelm Ave to Plaza Dr B 6.0 B 5.9 Turns from Site Driveway nla4 E 32.9 Left turn from Yelm Ave to Site Dwy nla B 6.9 1 Level of Service 2 Average seconds of delay per vehicle. 3. Volume-to-capacity ratio. 4. The site driveway would not exist for without-project conditions Site Access The proposed project would have four site access driveways: two on Yelm Avenue, and two on Vancil Road. Left turns out of the westernmost driveway on Yelm Avenue would not be allowed; this driveway would serve nght-in, left-Ill, and right-out traffic only All other access driveways are proposed as full access; they would serve right -in, right -out, as well as left -in and left -out movements. Analyses of site access conditions were performed to determine recommend turn-lane channelization and level of service. The WSDOT Design Manual guidelines for turn lanes were used to identify whether left- and/or right-turn lanes should be provided to accommodate project traffic at the proposed site access driveways on Yelm Avenue. Based on the project traffic assignment and future-with-project traffic forecasts, both site access driveways on Y elm Avenue would meet guidelines for right -turn lanes. Guidelines for the length of right-turn lanes indicate that the recommended length (assuming highway design speed of 40 mph and turning traffic design speed of 15 mph) would be 295 feet; the minimum length is 200 feet. However, to provide reasonable transition from the Vancil Road intersection and between site access driveways, the right-turn lane lengths would need to be shorter than 200 feet. Based on the length of right -turn lanes located directly across Y elm Avenue from the project site serving the QFC shopping center, a minimum right-turn lane length would be 150 feet. Both site access driveways on Yelm Avenue would also meet Design Manual guidelines for left-turn storage lanes. The left-turn, storage-lane length guidelines indicate that the westernmost driveway should have a 150- foot left-turn lane. Since there is approximately 350 feet between the two driveways on Yelm Avenue, the center, two-way, left-turn lane could serve the westbound left-turn storage needs of the Safeway project and the eastbound left-turn storage needs of Plaza Drive opposite this project. The easternmost driveway (dlfectly HEFFRON TRANSPORT AnON - 16- May 6, 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis across from Plaza Drive) should have a 200-foot left-turn storage lane serving westbound turns from Yelm Avenue to the Safeway project. That lane would eliminate the existing acceleration lane now serving left- turning traffi,c from Plaza Drive. Turn lanes at both site-access driveways were assumed for the following level of service analyses. Project generated traffic was assigned to the each of the site access driveways to determine levels of service. Approximately 85% of the project traffic destined to the west on Yelm Avenue was assigned to the Vancil Road intersections where protected left turns would be made at the realigned and signalized intersection with Yelm Avenue. Approximately 15% of the project traffic destined to the west on Yelm Avenue was assigned to the easternmost driveway (opposite Plaza Drive). Levels of service were calculated for all site access driveways; the Yelm AvenueIPlaza Drive/Safeway Drive intersection was analyzed previously in the Level of Service section (see Table 5). The turning volumes for the QFC driveway opposite the westernmost Safeway driveway were estimated for the purpose of this analysis. As summarized in Table 6 below, all three site access driveways would operate at LOS A (overall). The level of service analysis of the easternmost driveway (presented previously in Table 5) indicated that driveway would operate at LOS B (overall); the southbound left turn from Plaza Drive would operate at LOS F, the northbound left turn from the Safeway Drive would operate at LOS E. However, these movements may operate somewhat better due to the platoon affect of traffic signals at Vancil Road and Bald Hill Road. This platoon affect would provide longer gaps in conflicting through traffic than is assumed for the level of sefVlce calculations. In addition, drivers may choose to use the signal at Vancil Road to make protected left turns onto Y elm Avenue during peak conditions. Thus, the unsignalized left -turn access may become self-mitigating. Table 6 Site Access Level of Service Summary Unsianalized Intersections Yelm Avenue.NVestem Site Driveway (overall) Right turn from Safeway driveway Right turn from OFC driveway Left turn to Safeway driveway Left turn to OFC driveway Vancil Road/Northem Site Driveway (overall) Westbound turns from Safeway Site Southbound left turn to Safeway Site Vancil Road/Southem Site Driveway (overall) Westbound turns from Safeway Site Southbound left tum to Safeway Site 1 Levelofservice 2. Average seconds of delay per vehicle. LOS A B B B B A A A A A A Delay 0.5 77 64 7.0 5.0 1 1 3.1 2.4 1.5 2.9 2.2 Interim Vancil Road Conditions Currently the Vancil Road approach at Yelm Avenue is offset to the east from the QFC shopping center driveway A traffic signal controls movements at this intersection; turns from Vancil Road and the QFC shopping center driveway operate with split phases due to conflictIng turning paths that result from the offset. The City ofYelm plans to realign the Vancil Road approach to create a ninety-degree, four-leg intersection. However, due to property acquisition issues, it is unclear when this realignment could occur Therefore, these analyses were prepared to determine how long the existing channelization and signal configuration could operate with the proposed Safeway project. Background traffic forecasts were developed using turning movement counts performed in 1997, a 4% annual growth rate, and pipeline traffic estimates provided by the City of Yelm. Forecasts were prepared for years HEFFRON TRANSPORTATION - 17- May 6. 1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis 1999,2000,2004, and 2005 Traffic that would be generated only by the Safeway supermarket was added to the background forecasts for each future year It is likely that the retail portion of the shopping center would not happen for some time. It was assumed that all traffic destined to the west on Yelm Avenue would use the signal at Vancil Road as a worst case for all interim analysis conditions. This anlaysis was performed to determine when the growth in background traffic would degrade intersection operations to LOS F The level of service analysis results are summarized in Table 7 As shown, with the Safeway supermarket., the intersection would not degrade to LOS F until year 2005 due to growth in background traffic. Table 7 Level of Service Summary - Interim Vancil Road Conditions with Existing Geometry Existing Lane Geometry and Signal Operation LOS' Delay2 VlC Rati03 Analysis Year/Condiiton 1999 Without Project C 22.7 0.80 1999 With Safeway Only4 E 45.4 0.88 2001 With Safeway Only4 E 44.7 0.89 2004 With Safeway Only4 E 54.3 0.93 2005 With Safeway Onlyl F 65.5 0.97 1 LOS = Level of Service 2. Delay = Average delay per vehicle in seconds 3. VtC Ratio = Volume-to-capacity ratio 4. Assumes all traffic from the proposed 56,232-sf Safeway supermarket destined to the west would turn left from Vancil Road Based on these analyses, it appears that the existing lane configuration of the Vancil Road/Yelm Avenue intersection could support the worst-case Safeway traffic through year 2004 until background traffic degrades operations to LOS F This would allow the City of Yelm approximately six years to resolve the realignment issues and would be consistent with concurrency requirements since jurisdictions are required to have improvements constructed within six years to accommodate new development Traffic Safety The number of accidents may increase with the addition of new driveways and increase in turning movements generated by the Safeway project. The increase in through traffic on Yelm Avenue may also contribute to a proportionate increase in accident experience. The proposed Safeway project may adversely affect traffic operations at the Plaza Drive intersection immediately opposite the site's easternmost driveway Left-turn movements from Plaza Drive onto Yelm Avenue are forecast to operate at LOS F in 1999 without the proposed project. Without the Safeway project., drivers turning left from Plaza Drive are able to use the existing center lane as a left-turn acceleration lane. This allows them to make a two-step turn onto Yelm Avenue (a left turn to the center lane, then accelerate and merge with the through traffic) With the Safeway driveway, the center, left-turn lane would serve inbound left turns to the Safeway site and would not be available as often for outbound movements from Plaza Drive. As vehicle delays increase, drivers may accept smaller gaps m the traffic stream to maneuver, thus increasmg the potential for accidents. Transit and Non-Motorized Facilities Some additional pedestrian, bicycle, and transit use increase is expected as a result of the project. However, the increases are expected to be small. The project would be required to construct sidewalks along its frontage on both Yelm Avenue and Vancil Road. In addition, bike lanes would be required along the frontage on Yelm Avenue. These sidewalks and bike lanes would adequately serve the increase in pedestrian, bicycle, and transit actIvity generated by the project HEFFRON TRANSPORT A TllON - 18- May 6,1998 Yelm Safeway Store and Retail Center - Traffic Impact Analysis MITIGATION The proposed project would not degrade the overall level of service at any off-site intersection to unacceptable levels. Therefore, no specific transportation improvements would be required to mitigate the impact of the proposed project. However, the City of Yelm has established a '''transportation facilities charge' as a condition of development approval to pay for public facilities needed to serve new growth and development. " The current adopted fee is $750 per PM peak hour trip. The trip generation section of this report determined that the proposed shopping center would generate 450 new trips to the site during the PM peak hour This would relate to a total fee of$337,500 The City of Yelm is currently developing a credit system for projects that provide economic benefit to the City This methodology would consider the B & 0 tax and the City share of state sales tax generated by the project over a six-year period. The credit would be calculated as the portion of that tax that would be applied to the City road fund that is designated as private share for projects on the TFC. The City has estimated a credit for a 50,000-sf grocery store of approximately $18,500. In addition, Safeway may be asked to participate in funding the realignment of Vancil Road at Y elm Avenue once the right -of-way issues are resolved. Since this is a project planned by the City of Yelm, the cost contributed by Safeway to the realignment project would be credited against the total assessed TFC. As part of the proposed project, Safeway will be asked to pay for frontage improvements required as part of the development. These frontage improvements would include sidewalks on both Vancil Road and Yelm Avenue and a bike lane along Y elm Avenue. Right-turn deceleration lanes are recommended for both access driveways on Yelm Avenue; the turn-lanes are shown on the proposed project site plan. Left-turn storage lanes are also recommended. Since a center, two-way left-turn lane currently exists on Yelm Avenue, only some additional striping may be necessary to provide this storage. HEFFRON TRANSPORT A TmN - 19- Mav 6, 1998 APPENDIX Level of Service Definitions Levels of service (LOS) are qualitative descriptions of traffic operating conditions. These levels of service are designated with letters ranging from LOS A, which is indicative of good operating conditions with little or no delay, to LOS F, which is indicative of stop-and-go conditions with frequent and lengthy delays. Levels of service for this analysis were developed using procedures presented in the Highway Capacity Manual. Level of service for signalized intersections is defined in terms of delay Delay can be a cause of driver dis- comfort, frustration, inefficient fuel consumption, and lost travel time. Specifically, level of service criteria are stated in terms of the average delay per vehicle in seconds. Delay is a complex measure and is dependent on a number of variables including the quality of progression, cycle length, green ratio, and a volume-to-capacity ratio for the lane group or approach in question. Table A-I shows the level of service criteria for signalized intersections from the Highway Capacity Manual. Table A-1 Level of Service for Signalized Intersections level of Service A B C D Average Delay Per Vehicle less than 5.0 Seconds 5.1 to 15.0 seconds 15.1 to 25.0 seconds 25.1 to 40.0 seconds E 401 to 60.0 seconds F Greater than 60.0 seconds General Description Free flow Stable flow (slight delays) Stable flow (acceptable delays) Approaching unstable flow (tolerable delay-occassionally wait through more than one signal cycle befor proceeding. Unstable flow (approaching intolerable delay) Forced flow Oammed) For unSignallZed intersections, level of service is based on the average delay per vehicle for each turning movement. Delay is related to the availability of gaps in the main street's traffic flow, and the ability of a driver to enter or pass through those gaps. Table A-2 shows the level of service criteria for unsignalized intersections from the Highway Capacity Manual. Table A-2. Level of Service Criteria for Unsignalized Intersections Average Delay (seconds per vehicle) Less than 5.0 Level of Service A B C D E F 5.1 to 10.0 10.1 to 20.0 20 1 to 30.0 30 1 to 45.0 Greater than 45.0 Source Transportation Research Board, Hiahwav Capacity Manual, 1994.