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HomeMy WebLinkAboutTraffic Impact Analysis and Supplement ReportWILSON PARK PLAT "(°tRento, TRAFFIC IMPACT ANALYSIS nrrr9 Division CITY OF RENTON 200,c ftce#veo Prepared for Mr. Robert Wilson 21703601h St. E. Lake Tapps, WA 98391 Prepared by IVOR THWES T TPAFFlc EXPERTS 11410 NE 124"! St., #590 Kirkland, Washington 98034 Telephone: 425.522.4118 Fax: 425.522.4311 June 23, 2009 TIS o ' e 5 e,-6 tA d p avl C V EXHIBIT 12,; rraffZ&( iYDRTh FT TRAFFIC EXPERTS 1141011' 1eyth SI., #590 KirWa.gd, VA 95034 Phom. 425.522.41 18 Fax 425.522.4811 June 23, 2009 Mr. Robert Wilson 21703 60" St_ E. Lake Tapps, WA 98391 Re: Wilson Park Short Plat - City of Renton Traffic Impact Analysis Dear Mr. Wilson: We are pleased to present this traffic impact analysis report for the proposed 14 lot Wilson Park Residential short plat located at the 720 S. 55"' St. in the City of Renton. The scope of this analysis is based upon the preliminary plat site plan, the Ci of Renton Policy Guidelines for Traffic Impact Analysis for New Development, and conversations with City Renton staff. Our summary, conclusions and recommendations begin on page seven of this report. PROJECT DESCRIPTION Figure 9 is a vicinity map showing the location of the site and study area. Figure 2 is a close in area map showing the site location and surrounding street network. Figure 3 shows the preliminary site plan. The primary access street runs from the southwest corner of the site to S 55th St. through a 50 ft. wide easement on the parcel adjacent to the south side of the site. The primary access from S. 55"' St. to the site is 28 ft. wide with a sidewalk on the west side of the street. A secondary gated emergency vehicle access connects to S 551' St. though a 30 ft. easement. Streets within the site will be 32 ft. wide with a sidewalk on one side. The primary site access street is located on the outside of a horizontal curve on S 55t" St. to optimize sight distance in both east and west directions for vehicles exiting the site. Page i Wilson Park ?raffmy Development of the Wilson Park plat is expected to occur by the year 2011. Therefore, for purposes of this study, 2011 is used as the horizon year for this study. An existing single family home within the project site will be removed with this development. TRIP GENERATION AND DISTRIBUTION The 14 single-family units in the proposed Wilson Park Plat are expected to generate the vehicular trips during an average weekday and during the street traffic peak hours as shown below: Time Period Trip Rate Trips Trips TotalTripsperunitEnteringExiting 67 157 Average Weekday 9.57 134 50% 50% AM Peak Hour 0.75 8 1125% 75% PM Peak Hour 1.01 5 14639370 A vehicle trip is defined as a single or one direction vehicle movement with either the origin or destination (exiting or entering) inside the study site. The trip generation is calculated using the average trip rates in the Institute of Transportation Engineers (ITE) Trip Generation, Eighth Edition, for Single Family Detached Housing (ITE Land Use Code 210). These trip generation values account for all site trips made by all vehicles for all purposes, including resident, visitor, and service and delivery vehicle trips. Figure 4 shows the estimated trip distribution and the calculated site -generated traffic volumes_ The distribution is based on existing traffic volume patterns, the characteristics of the road network, the location of likely trip origins and destinations employment, shopping, social and recreational opportunities), expected travel times, and previous traffic studies. Page 2 Tra EXISTING PHYSICAL CONDITIONS Street Facilities Figure 5 shows existing traffic control, number of street lanes and other pertinent information. The streets in the study area are classified per the City of Renton Comprehensive Pian as follows: Talbot Rd. S Collector Arterial S 55th St. Local Access 98th Ave S Local access 98th Pi. S Local access 102nd Ave S Local access S 55th St. consists of two 11 ft. lanes and a shoulder that varies in width from approximately two to four feet in the vicinity of the project site. A section of S 55th St. east of the project site consists of several sharp curves and is posted with a 15 mph advisory speed sign and with chevron arrows at each curve within the section. There is a left turn pocket on S 55th St. at 98th Ave. S, approximately 125 ft. west of the Wilson Park site access street. EXISTING TRAFFIC CONDITIONS Traffic Volumes Figure 6 shows existing, future without project and future with project PM peak hour traffic volumes at the proposed site access street/S 55t' St. intersection. The proposal generates less than 30 PM peak Dour trips and no other intersection or street segment in the City of Renton will experience an increase of 5% in traffic volumes due to this development. Therefore, only the site access street/S 55ffi St. intersection requires a level of service (LOS) analysis per the Ci of Renton Policy Guidelines for Traffic Impact Analysis for New Development. A PM peak hour traffic count was performed on Tuesday, .lune 16, 2509 and is included in the Technical Appendix. Level of Service Analysis Level of Service (LOS) is a qualitative measure describing operational conditions within a traffic flow, and the perception of these conditions by drivers or passengers. These conditions include factors such as speed, delay, travel time, freedom to maneuver, traffic interruptions, comfort, convenience, and safety. Levels of service are given letter designations, from A to F, with LOS A representing the best operating conditions (free flow, little delay) and LOS F the worst (congestion, long delays). Page 3 Wilson Park Tra Generally, LOS A and B are high, LOS C and D are moderate and LOS E and F are low. Table 1 shows calculated level of service (LOS) for future conditions including project traffic at the pertinent street intersection. The LOS was calculated using the procedures in the Transportation Research Board Highway Capacity Manual 2000. The LOS shown indicates overall intersection operation. At intersections, LOS is determined by the calculated average control delay per vehicle. The LOS and corresponding average control delay in seconds are as follows; TYPE OF INTERSECTION A B C D E F Signalized 9 0. X10.0 and X20.0 and 35.0 and 55.0 and 80. 0 20.0 35.0 55.0 80.0 0 Stop Sign Control 1 0 . 10 and <15 15 and 525 f 25 and <35 35 and X50 50 Accident History Historical accident data for the section of S. 55"' St. between the intersections 98t" Ave. S and 99t" PI S was obtained from the City of Renton. A total of 4 accidents occurred from January 1, 2004 through December 31st 2008. Three accidents occurred on the street section between the intersections, one accident occurred at 99"' PI S and no accidents occurred at 98tf' Ave. South. Two of the accidents were injury type accidents with one being a fatality, The fatality was a single vehicle travelling in the westbound direction approximately 319 ft west of 99"' Pl. South. None of the accidents occurred at the curve on S. 55"' St. where the site access street is proposed to be located. Based on the field review and historical accident data there are no readily apparent safety issues that should result from the proposed development. The historical accident data is included in the technical appendix. FUTURE TRAFFIC CONDITIONS (WITHOUT THE PROJECT Figure 6 shows projected 2011 PM peak hour traffic volumes without the project_ These volumes include the existing traffic volume counts plus background traffic growth. The background growth factor accounts for traffic volumes generated from other approved but unbuilt subdivisions and general growth in traffic traveling through the area. A 3% per year annual background growth rate was added for each year of the two year time period from the 2009 traffic count to the 2011 horizon year of the Page 4 Wilson Park rraffmy proposal. Cit of Renton historical traffic count data supports the 3% per year growth rate on S. 55 Street. FUTURE TRAFFIC CONDITIONS WITH PROJECT Figure 6 shows the projected future 2011 PM peak hour traffic volumes with the proposed project. The site -generated PM peak hour traffic volumes shown on Figure 4 were added to the projected future without project volumes to obtain the future with project volumes. Table 1 shows calculated LOS for future with project volumes at the Wilson Park site access street/S. 55th St. intersection. The study intersection operates at an excellent LOS A for future 2011 conditions including project -generated traffic. SIGHT DISTANCE EVALUATION Sight distance on S 55th St. is excellent looking to the west from the proposed site access street and extends approximately 785 ft. to Talbot Rd. South. Sight distance to the east is limited by a horizontal curve on S 55u' Street. This curve has a posted advisory speed of 15 mph. In evaluating sight distance, the generally accepted rule is to add 5 mph to the posted speed to determine the design speed of the street. Sight distance requirements looking to the east from the Wilson Park site access street are therefore based on a 20 mph design speed for the horizontal curve on S 55th Street. Intersection sight distances and stopping sight distances were measured and compared to City requirements at the Wilson Park site access street/ S 55th St. intersection. City of Renton is requirements are based on current AASHTO "Geometric Design of Highways and Streets" standards. Intersection Sight Distance AASHTO standards for a 20 mph design speed require an intersection sight distance of 145 ft. looking to the left (east) from the site access street (using an eye height of 3.5 ft. and a vehicle height of 4.25 ft.). Attached in the technical appendix are Exhibits 9-55 and 9.58 showing the current AASHTO standards for intersection sight distance. A right tuming vehicle exiting from the side street is required to enter the westbound lane and accelerate to 85% of the design speed so as not to interfere with the traffic flow. The field measured intersection sight distance looking to left (east) from the site access street is 215 ft. thus exceeding the AASHTO required 145 feet. Intersection sight distance looking to the right from the site access street is excellent and extends all the way to Talbot Rd. S at approximately 785 ft. Page 5 Wilson Park lrrafmf Stopping Sight Distance Stopping sight distance is the distance traveled while the vehicle driver perceives a situation requiring a stop, realizes that stopping is necessary, applies the brake, and comes to a stop. A stopping sight distance of 115 ft. is required for a 20 mph design speed (using an eye height of 3.5 ft. and an object height of 2 ft.). Attached in the technical appendix is Exhibit 3-1 showing the current AASHTO standards for stopping sight distance. There is an approximate 10% downgrade in the westbound direction on S 55h Street_ The required stopping sight distance is therefore increased an additional 40 ft. to account for a 10% downgrade with a 20 mph design speed. The required westbound stopping sight distance therefore is 115 + 40 = 155 feet. The field measured westbound stopping sight distance is 197 ft. thus exceeding the required 155 feet. Stopping sight distance for eastbound vehicles on S. 55th St. is excellent and extends from Talbot Rd. S. approximately 785 feet to the site access street. The City of Renton AASHTO based intersection and stopping sight distance requirements are met at the Wilson Park site access street/ S 55th St. intersection in both the east and west directions. TRAFFIC MITIGATION REQUIREMENTS The City of Renton requires a Transportation Mitigation Fee payment of $75 per new daily trip attributed to new development. One existing single family home on site will be removed. with this development resulting in a net increase of 13 single family homes. The net new daily trips due to this development are 124 trips (13units x 9.57 daily trips per unit). The estimated Transportation Mitigation Impact Fee is $9,300 (124 daily trips X $75 per daily trip). Page 6 M1 rk SUMMARY, CONCLUSIONS AND RECOMMENDATIONS We recommend that the Wilson Park Plat be constructed as shown on the site plan with the following traffic impact mitigation measures: Construct the street improvements including curb, gutter and sidewalk for site access street and intemal site streets as shown on the site pian. Contribute the approximately $9,300 Transportation Mitigation fee to the City of Renton. No other traffic mitigation should be necessary. If you have any questions, please call 425-522-4118. You may also contact us Via e-mail at vinoe nwtraffex_eom or IarNCab_nwtrafFex.com. Very truly yours, Vincent J. Geglia Principal TraffEx Page 7 C AL. j-1 ate. 3-a Larry D. Hobbs, P.E. Principal TraffEx TABLE 1 PM PEAK HOUR LEVEL OF SERVICE SUMMARY WILSON PARK PLAT TRAFFIC IMPACT ANALYSIS INTERSECTION EXISTING 2009I VWTHOTUT PROJECT Site Access St/S 55h St. I NA I NA I SB (A 9.9) Number shown is the average control delay in seconds per vehicle for the worst approach or movement which determines the LOS for an unsignalized intersection per the Transportation Research Board Highway Capacity Manual 2000 XX) LOS and average control delay for the worst approach or movement at an unsignalized intersection SB) southbound approach Page 8 S1 t9i I I L rraffe-Z vZ7jqrHWE*S7- TRA FFIC EXF"ERT.5 C. a -.. .. .+_ x_11i= ST PL it LO PIL k LJ fop M-11 Pra*et Sfite__ _ , Wilson Park Plat - City of Renton Vicinity Map Figure 1 f T 1 II 1 {e /VOLT NW—S7- 1 , i Y•xY ^ r . .r if7A FF1G EXPE"f2TS• a. 557 i:T• : " qtr---5 i83Tr..T'^" f., ri Y=f' Nwtl Ofmn s • _. - + T i NOV 17 6Gr W, If Ar . Wilson Park Plat - City of Renton Area Map Figure Z s 4 y 1 Ar . Wilson Park Plat - City of Renton Area Map Figure Z 9I ixay 5,'6" ?£cam. t :wF III ii7i `"All-n I 1 1 ! fKY LIIp M1 s01CIQ,W [is J.SS• Al 9Is S Ait4 NOT Maw 71 I: ! Ir 1 j --- -} r- v 11164---1 k t2 M1 yf•tsl Z_ as _l " rl - - Y _ J 4. a _ _ L _:" J I '' ^. 9 , :• i I i ,ry a -ax is;#/ i - - a ! ]ra]os=nl3 >: 4: !' \\ I _ r I1r51' fin -o° -- - - - - - - ,> or'. ' - , 5 I a(55' t :ar., I. IJ t 1• a(F ur toKF 4•]R l lYH S} p ' i C . r- _ _ _ _ _ _ ` Lin ' r - drySAva6. lA I «SI IrII r 3 I' 1063 rlLSIae..Y N7', S u}' I Y U lR ftf :1 p a I 14Nrtrf 9F 1 re]-ef 1 X • r+.mar* ' / tarl[T tette m xaeaerftauau I r I o' 1 L ' ., _ uxzsc 1aRt]!}_WS-9119 ws x : fit f if II I ' -j I 1 ,` r%'F '' r wAm" Sa f am -QS o i I `Y. F.T;f 1 . 12W I y I ] Yr a SIB Ajoy 11 316 +3 lFdJ a2 ~ T a IBJ mar .b"E onfew COM" mmulwar am m rur rnr s elnr-ul ` I. ,, If ' E77 aFC nu'E7ffa+Kareu9 \ Li Wfi (177faYL91rLl MM 0 1n tom o SE S Wilson Park Plat - City of Renton Figure Site Plan 1 3 i 65% t 79% 3 yT S;STy ;T 4 t 14% T S 14 f,1 ST 7.s `k- 2 0-0- 0 PM Peak Hour Traffic Volume Enter 9 Exit 5 Total 14 Wilson Park Plat - City of Renton PM Peak Hour Trip Generation and Distribution rra`. 7'f2AFFIG EXPERTS sz 19C{ f V SE t97-1 ST 7% 14% 3 S-.- i92,e1- ST 4 Legend 15% Percentage of Project Traffic 3 PM Peak Hour Traffic Volume Figure 4 Wilson Park Plat - City of Renton Figure Existing Conditions - 5 Legend 2 Lanes Number of travel lanes 25 mph Speed Limit Stop Sign Control r-- NpR r,YwE3T TRAFFIC' EXPERTS n a'r 197T.i 5T d SE TWDO ST S Spar_ S V S 6 E C J 3r3 N N l!7 N 2 Lanes2Lanes 2 Cartes4 sr s ssT., s -r 15 mph T 25 mph 25 mph ECL EJlf N N N co a T F Wilson Park Plat - City of Renton Figure Existing Conditions - 5 Legend 2 Lanes Number of travel lanes 25 mph Speed Limit Stop Sign Control Advisory Speed Sign Wilson Park Plat - City of Renton Figure Existing Conditions - 5 I ta"na ST s SSTH sT S?T•. "sl i Future Future Without With Existing Project Project CD 0 p - 0J ti d 466-0`121 e Accessi S 55th St CD C) 6 JJ 1%- 4 494-0-128 I Site Access! S 55th S! JVORrt>'WEST TATA FFlC EXPEP TS l93T•i ! T r 7 2 494-0`128 e Access! S 55th S t SZ: 1907• i —r S; t'V-e2 ;r Wilson Park Plat - City of Renton Figure PM Peak Hour Volumes for Existing and Future Conditions 6 Preps C. Nr' Tex Traf -c Count Consultants, Inc. Phone: (425) 861-8866 FAX: (425) 861.8877 F -Mail: TMincigaol.com WBEfDBE Intersection: 9Bth Ave S @ S 55th St Date of Count: Tues 6116!09 Location: Renton Checked By: LBP Tme From North on (SB) From South on (NI3) From Easton (WB) From West on (EB) Interval Interval 98th Ave S 96th Ave S S 5th St S 5th St Total Ending at T L S R T L S R T L S R T L I5 R 4:15 P 0 0 0 0 0 1 0 1 0 2 29 0 0 0 66 1 1 122 4:30 P 0 0 0 0 0 0 0 0 1 1 24 0 1 0 771 103 4745 P 0 0 0 0 0 0 0 2 0 1 32 0 0 0 109 0 144 5:00 P 0 0 0 6 0 0 0 1 0 0 34 0 0 0 124 1 160 5:15P 0 0 0 0 0 0 0 0 0 0 17 0 0 0 116 3 138 5:30 P 0 0 0 0 0 2 0 0 0 1 36 0 0 0 112 0 151 5:45 P 0 0 0 0 0 1 0 1 0 1 23 0 0 0 106 1 135 6:00 P 0 0 0 0 0 0 0 0 0 0 29 0 0 0 60 1 110 6:15P 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 SM IF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6:45P 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7:00P Otto 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total Survey0 0 0 0 0 2 0 01. 0 0 4 D 5 1 6 224 1 0FToTsir, HV r0a rda B 1063 0.0% Peak Hour. 4:30 PM to 5.30 PM Total0 0 0 0 0 2 0 3 0 2 119 0 0 463 1 4 593 Iproach 0 5 121 467 593 HV r0a rda Ma NO 0.0% PHF nia 0.63 0.82 0.93 0.93 K •tram: INT 91 INT 02 INT D3 INT D4 INT 05 INT 06 INT 07 INT 08 INT 09 NT i0 MT 11 INT 12 S 5th St 121 I Peds 0 Bike! J . ssa a67 N S E w No Peds 01 0 01 0 i a_: 4:30 PM to 5:30 PM 4 ......... Ped' +_ 4 _ [ 0 Bikef _p __1 E 0 0 0 0 0 0 0 98th Ave S 0 Bleyciss From: N S E 0 INT 01 0 fNT 02 0 INT 03 0 INT D4 0 INT 05 0 INT 06 INT 07 INT 06 2 0 Special Notes: 0 0 0 0 0 0 2 0 2 s 5th St 119 121 2 1 587 I 0 IBike Ped 3 fi4D 1.0 PHFPeuk Hour Volume PHF %HV EB 093 nla Check WB 0.82 n/a In. 593 NB 0.63 nla Got: 593 SB n1s nla Intersection 0.93 0.0% 0 Special Notes: 0 0 0 0 0 0 2 0 2 f b '1;r10 J9 L3-55 PAX 424 3:10 7376 W t- 0 fl RENTON TRANS- SYS T 0 a f; m u i.J rV S c J n L:. 4V v u r 0 a f; m u i.J rV S c L 0 a f; C-1 C o CJ r v v f, U3 rr 4 7 L' w CW C C'- i e v 3 1 G Z. 0 a f; Imz2onB „:5§ F. Jn ;376 RE\ TRANS. Sys. T s u ^ r * ml j Q § p e V3 Q S a c 9 j E d $ b a r 3 4 k m 0o; TWO WAY STOP CONTROL SUMMARY jeneral information ite Informati, Analyst Intersection Agency/Co. urisdiction Renton Date Performed 6119/2009 Analysis Year 2011 Future with Project Analysis Time Period M eak 1ro'ect Description astlWest Street: S 55th St North/South Street: Site Access St ct' n Orientation• East-West Stud Period hrs : 0.25terse10 Vehicle Volumes and Adjustments Major Street Eastbound Westbound Movement 1 2 3 4 5 B L T R L T R Volume 7 494 0 0 128 2 eak-Hour Factor, PHF iourly Flow Rate, HFR 0.93 1 7 0.93 531 0.93 0 0.93 0 0.93 137 0.93 2 ercent Heavy Vehicles 0 0 Vledian Type Undivided ZT Channelized 0 0 anes 0 1 0 0 1 0 onfiguration LT TR J stream Si nal 0 0 Minor Street Northbound Southbound Movement 7 L 8 T 9 R. 10 L 11 T 12 R Joiume 0 0 0 1 0 4 eak-Hour Factor, PHF 0.93 0.93 0.93 0.93 0.93 0.93 iourly Flow Rate, HFR 0 0 0 1 1 0 1 4 Dercent Heavy Vehicles 0 0 0 0 0 0 Dercent Grade (%) 0 0 cared Approach N N Storage 1 0 0 RT Channelized 0 0 anes 0 0 0 0 0 0 onfiguration LR 3ela , Queue Length, and Level of Service pproach EB WB Northbound Southbound Movement 1 4 7 8 9 10 11 12 ane Configuration LT LR vph) 7 5 m) (vph) 1457 738 0.00 0.01 15% queue length 0.01 0.02 ontrol Delay 7.5 0.9 OS A A 4pproach Delay 9.9 4pproach LOS A rcS2000'1im Copyright C 2000 University ofFlorida, All Rights Reserved Version 4.1 AASHTD--Geometric Dej!A ighways and Streets Time gap (a) at design spud of Desi n vehicle ma r read Passenger car 6.5 Single -unit truck 8.5 Commination truck 1015 Note: Time gaps are for a stopped vehicle- to turn right onto or cross a two-lane highway with no median and grades 3 percent or less. The table values require adjustment as follows: For multilane highways: For crossing a major road with more than two lanes, anti 0.5 seconds for passenger cars and 0.7 seconds for trucks for each additional lane to be crossed and for narrow medians that cannot store the design vehicle. For minor road approach grades: If the approach grade is an upgrade that exceeds 3 percent, add 0.1 seconds for each percent grade. ExWbit 9-57. Time Gap for Case B2, -Right Turn from Stop and Case B3 -,-Crossing Maneuver Note: iratarsection sight distance shown is for a stopped passenger car to tum right onto or crass a two-lane highway with no median and grades 3 percent or less.' For other conditions, the time gap must be adjusted and required sight distance recalouiatsd. ambit 9-58. Design Intersection Sight once ---Case gam --Right Turn from Stop and Case W-Ccossing Maneuver M Metric- lus Custal1l) Y Intersection sight Intersection sight Stopp€ng distance for Stopping distance for Design sight_ passenger cars Design sight Essen er cars speed distance Calculated Design speed distance Calculated Design tmlh m rn rn h it ft t 20 20 36.1 40 15 80 143.3 145 30 35 54.2 55 20 115 191.1 195 40 5o 72.3 7S 25 15.5 _ 236,9 240 50 65 90.4 95 30:. .. 204 286.7 290 60 85 1 fi8.4 110 250 334.4 335 70 105 126.5 130 35 40 . 305 362.2- 385 80 130 144.6 145 45 360 430.0 434 S0 160 162.6 165 50 4:25 477.8 480 100 185 180.7 185 55 495 525.5 530 110 220 198.8 200 60 570... 573.3 575 120- 259 216.6 220 65 645 621.1 625 130 285 234.9 2- 5 70 730 668.9 670 75 820' 716.6 720 80.. 910 764.4 765. Note: iratarsection sight distance shown is for a stopped passenger car to tum right onto or crass a two-lane highway with no median and grades 3 percent or less.' For other conditions, the time gap must be adjusted and required sight distance recalouiatsd. ambit 9-58. Design Intersection Sight once ---Case gam --Right Turn from Stop and Case W-Ccossing Maneuver M Irttersecrfons Note. Intersection sight distance shown is for a stopped passenger car to tram left onto a two-lane highway with no median and grades 3 percent or less. For other conditions, the time gap rntW be adjusted and required sight distance recalculated. Exhibit 9-55. Design Intersection Sight Dist nce-_4 me BI—Left Tura From Stop Sight distance design for left turns. at divided -highway intersections ghould consider multiple design vdhicles and median width. If the design vehicle used to determine sight distance for a divided -highway intersection is larger than a passenger car, then sight distance for left turns will need to be checked for that selected design vehicle and for smaller design vehicles as well. If the divided -highway median is wide enough to stare the design vehicle with a clew%nce to the through lanes of approximately I m (3 ft] at both ends of the vehicle, no separate analysis for the departure sight triangle for Ieft turns is needed on the minor -road approach'for the near roadway to the left. In most cases, the depart= -sight triangle for right turns (Case 132) will provide sufficient sight distance for a passenger car to cross the .near roadway to reach the median. Possible exceptions are addressed in the discussion of Case B3. If the design vehicle can be std in the median with adequate clearance to the through lanes, a departure sight triangle to the right for. left turns should be provided for that design vehicle taming left from the median roadway. Where the, ax:dian is not wide enough to store the design vehicle, a departure sight triangle should be.proyided for that design vehicle to turn left from the minor -mad approach. The median width should be considered in determining the number of lanes to be crossed. The median width should be converted to equivalent lanes. For example, a 7-2-m 124 -ft] median should be considered as two additional lanes to be crossed in applying the multilane highway adjustment for time gaps in Exhibit 9-54. Furthermore, a departure sight triangle for left turns from the mtr dian roadway should be provided for the largest design vehicle that can be stared on r1 Metric US custalna fntersectiorn sight Intersedlon sight Stopping distance for . Stopping distance for Design sight ssen er cars Design sight p2astNer cars speed distance Calculated Design speed distance Calculated Design krnlh to m m Meh) ft ft ft 20 20 41.7 45 15 80 185.4 170 30 35 62.6 65 20 115 2211.5 225 40 50 85,4 8s 25 155 275.6 50 65 104.3 105 30 200 330.6 335 84 85 12511 130 35 250 385.9 390 70 105 146.0 150 40 305 441.0 445 80 130 166.8 170 45 360 496.1 5D0 90 160 187.7 190 50 425 551.3 555 100 185 208.5 210 55 495 606.4 610 110 220 229.4 230 60 570 661.5 665 120 250 250.2 255 65 M 716.6 720 130 28,5 271.1 275 70 730 771.8 775 75 820 826.9 830 80 910 882.0 885 Note. Intersection sight distance shown is for a stopped passenger car to tram left onto a two-lane highway with no median and grades 3 percent or less. For other conditions, the time gap rntW be adjusted and required sight distance recalculated. Exhibit 9-55. Design Intersection Sight Dist nce-_4 me BI—Left Tura From Stop Sight distance design for left turns. at divided -highway intersections ghould consider multiple design vdhicles and median width. If the design vehicle used to determine sight distance for a divided -highway intersection is larger than a passenger car, then sight distance for left turns will need to be checked for that selected design vehicle and for smaller design vehicles as well. If the divided -highway median is wide enough to stare the design vehicle with a clew%nce to the through lanes of approximately I m (3 ft] at both ends of the vehicle, no separate analysis for the departure sight triangle for Ieft turns is needed on the minor -road approach'for the near roadway to the left. In most cases, the depart= -sight triangle for right turns (Case 132) will provide sufficient sight distance for a passenger car to cross the .near roadway to reach the median. Possible exceptions are addressed in the discussion of Case B3. If the design vehicle can be std in the median with adequate clearance to the through lanes, a departure sight triangle to the right for. left turns should be provided for that design vehicle taming left from the median roadway. Where the, ax:dian is not wide enough to store the design vehicle, a departure sight triangle should be.proyided for that design vehicle to turn left from the minor -mad approach. The median width should be considered in determining the number of lanes to be crossed. The median width should be converted to equivalent lanes. For example, a 7-2-m 124 -ft] median should be considered as two additional lanes to be crossed in applying the multilane highway adjustment for time gaps in Exhibit 9-54. Furthermore, a departure sight triangle for left turns from the mtr dian roadway should be provided for the largest design vehicle that can be stared on r1 AASHTO--Gcvmctric Desig .ighways and Streets v c th h 0 IOU) d t3 8 g m wsua o o o cvtirri c rth ay m L E t o v r cv co a av v *vtow cq ea ECIDa?gaerepcnttCeh+[fnc aiC mCx -0 o cv0wca.-i ivmvvt c a.- N cv c*a v to as cq cn M r- O U rU'>M ' 00 'gr C3 cm– lii L7tD 7f gs i lvt4caC{Q( Cd? j fi v C11NLitRcpq yt' O 0Ctoa0Q nInoIrlQltiQ p a cc fn coWN Nc 1TiO © j Y cd tOrC*1 F s7opvoC Nu70?t- r- r- N N 04 F tp m etT`t*tvvmtiapcVepiC, W CO .- to m ai v Cd tri CiV) e< +- .- cv v un P- 0) M tD rn W03770r -r V RF sic ° u o m cc <0r- t (D n Lo Lo Nk"t o +- t jCT4- v3v4 cdc0-N. 0) QTS ala t va)N u? [O t ts] O cvmJE 112 WILSON PARK DIVISION 2 PLAT SUPPLEMENTAL TRAFFIC IMPACT ANALYSIS CITY OF RENTON Prepared for Mr. Robert Wilson 21703 60t" St. E. Lake Tapps, WA 98391 Prepared by r0qffEX 7-14.4 FFl c EXPERT -s 11410 NE 124" St., #590 Kirkland, Washington 98034 Telephone: 425.522.4118 Fax: 425.522.4311 January 25, 2012 city Of r-'ento-, DVi5,C11 h,. 2 qp+wV7 Fay Com - EXHIBIT 12 6 rraff,my January25, 2012 Mr. Robert Wilson 21703 60th St. E. Lake Tapps, WA 98391 Re: Wilson Park Division 2 Plat - City of Renton Supplemental Traffic Impact Analysis Dear Mr. Wilson: NCRTHWEST TRAFF/C eXPERTS 11410 NE 124th St. #590 KWr 1, 0 98034Phone. 425.522,4118 Fax: 425,522.4311 We are pleased to present this supplemental traffic impact analysis (TIA) for the proposed 10 lot Wilson Park Division 2 Plat located on the north side of S.551h St. in the City of Renton. This TIA supplements the information and analysis presented in the original Wilson Park Plat TIA, dated June 23, 2009, prepared by Traffex. The Wilson Park Division 2 site is adjacent to the southwest corner of the approved Wilson Park Plat. The proposed project site contains the access road to S. 55 h St. for Wilson Park Plat. The 10 lots of the proposed Wilson Park Division 2 will have direct driveway connections to the access road connecting the Wilson Park to S. 55th Street. The access road and the location of its intersection to S. 55th St remains the same as when approved for the original Wilson Park Plat. The scope of this analysis is based upon the preliminary plat site plan, the Cityof Renton Policy_ Guidelines for Traffic Impact Analysis for New _Development. Our summary, conclusions and recommendations begin on page 5 of this report. PROJECT DESCRIPTION Figure 1 shows the Wilson Park Division 2 site plan. The site lies between the southwest corner of the Wilson Park plat and S. 55th Street. The proposed project utilizes the same access to S. 55th St. as the approved 12 lot Wilson Park plat. The site access street intersects S. 55th St. on the outside of a horizontal curve on S. 55th St. to optimize sight distance in both east and west directions for vehicles entering and exiting the site. Page 1 Wilson Park Trafff wC Development of the Wilson Park Division 2 plat is expected to occur by the year 2014. Therefore, for purposes of this study, 2014 is used as the horizon year for this study. TRIP GENERATION AND DISTRIBUTION The 10 single-family units in the proposed Wilson Park Division 2 Plat are expected to generate the vehicular trips during an average weekday and during the street traffic peak hours as shown. below: Time Period Trip Rate Trips Trips Total Trips per unit Entering Exiting 48 Average Weekday 9.57 96 500 % 50% AM Peak Hour 0.75 2% 6875% PM Peak Hour 1.01 41063% 37% A vehicle trip is defined as a single or one direction vehicle movement with either the origin or destination (exiting or entering) inside the study site. The trip generation is calculated using the average trip rates in the Institute of Transportation Engineers (ITE) Trip Generation Eighth Edition, for Single Family Detached Housing (ITE Land Use Code 210). These trip generation values account for all site trips made by all vehicles for all purposes, including resident, visitor, and service and delivery vehicle trips. Figure 2 shows the site generated traffic volumes and distribution at the study intersection. The distribution is based on existing traffic volume patterns, the characteristics of the road network, the location of likely trip origins and destinations employment, shopping, social and recreational opportunities), expected travel times, and previous traffic studies. EXISTING PHYSICAL CONDITIONS The streets in the study area are classified per the City of Renton Comprehensive Plan as follows: Talbot Rd. S S55 1h St. Page 2 Collector Arterial Local Access Wilson Park rraffmy 98th Ave S Local access 98th PI. S Local access 102nd Ave S Local access S 551h St. consists of two 11 ft. lanes and a shoulder that varies in width from approximately two to four feet in the vicinity of the project site. A section of S 55th St, east of the project site consists of several sharp curves and is posted with a 15 mph advisory speed sign and with chevron arrows at each curve within the section. There is a left tum pocket on S 55th St. at 981h Ave. S, approximately 125 ft. west of the Wilson Park site access street. EXISTING TRAFFIC CONDITIONS Traffic Volumes Figure 2 shows existing, future without project and future with project PM peak hour traffic volumes at the proposed site access street/S 55th St. intersection. The proposal generates less than 30 PM peak hour trips and no other intersection or street segment in the City of Renton will experience an increase of 5% in traffic volumes due to this development. Therefore, only the site access street/S 55th St. intersection requires a level of service (LOS) analysis per the City of Renton Policy Guidelines for Traffic Impact Analysis for New Development, A PM peak hour traffic count taken for the Wilson Park Plat TIA was used for this supplemental analysis since traffic growth in the area has been generally flat over the past several years. Level of Service Analysis Level of Service (LOS) is a qualitative measure describing operational conditions within a traffic flow, and the perception of these conditions by drivers or passengers. These conditions include factors such as speed, delay, travel time, freedom to maneuver, traffic interruptions, comfort, convenience, and safety. Levels of service are given letter designations, from A to F, with LOS A representing the best operating conditions (free flow, little delay) and LOS F the worst (congestion, long delays). Generally, LOS A and B are high, LOS C and D are moderate and LOS E and F are low. Table 1 shows calculated level of service (LOS) for future conditions including project traffic at the pertinent street intersection. The LOS was calculated using the procedures in the Transportation Research Board Highway Capacity Manual 2000. The LOS shown indicates overall intersection operation. At intersections, LOS is determined by the calculated average control delay per vehicle at signalized intersections or the average delay for the worst minor approach at two way stop sign controlled intersections. The LOS and corresponding average control delay in seconds are as follows: Page 3 Wilson Park rraffay TYPE OF INTERSECTION A B C D E F Signalized 10 10.0 and 20.0 and 35.0 and 55.0 and 80. 20.0 35.0 55.0 80.0 0 Stop Sign Control 1 10 and X15 15 and X25 25 and <35 35 and X50 50 FUTURE TRAFFIC CONDITIONS WITHOUT THE PROJECT Figure 2 shows projected 2014 PM peak hour traffic volumes without the project. These volumes include the existing traffic volume counts, plus background traffic growth, plus 12 PM peak hour pipeline project trips generated by the Wilson Park plat. The background growth factor accounts for traffic volumes generated from other approved but unbuilt subdivisions and general growth in traffic traveling through the area. A 3% per year annual background growth rate was added for each year of the five year time period from the 2009 traffic count to the 2014 horizon year (for a total of 15%). This will result in a very conservative analysis since traffic volumes in the area have been generally flat for the past several years and are anticipated to continue this trend. FUTURE TRAFFIC CONDITIONS WITH PROJECT Figure 2 shows the projected future 2014 PM peak hour traffic volumes with the proposed project. The site -generated PM peak hour traffic volumes were added to the projected future without project volumes to obtain the future with project volumes. Table 1 shows calculated LOS for future with project volumes at the Wilson Park Division 2 site access street/S. 55th St. intersection. The study intersection operates at a high LOS B for future 2014 conditions, including project -generated traffic, and meets the City of Renton LOS requirements for intersections. SIGHT DISTANCE EVALUATION Sight distance on S 55th St. at the proposed site access street was extensively evaluated in the Wilson Park TIA and meets the City of Renton intersection and stopping sight distance requirements in both the east and west directions. Page 4 Wilson Park Traffmy TRAFFIC MITIGATION REQUIREMENTS The City of Renton requires a Transportation Mitigation Fee payment of $75 per new daily trip attributed to new development. The net new daily trips due to this development are 96 trips (10units x 9.57 daily trips per unit). The estimated Transportation Mitigation Impact Fee is $7,200 (96 daily trips X $75 per daily trip). SUMMARY, CONCLUSIONS AND RECOMMENDATIONS We recommend that the Wilson Park Division 2 Plat be constructed as shown on the site plan with the following traffic impact mitigation measures: Construct the street improvements including curb, gutter and sidewalk for site access street as shown on the site plan. Contribute the approximately $7,200 Transportation Mitigation fee to the City of Renton. No other traffic mitigation should be necessary. If you have any questions, please call 425-5224118. You may also contact us via e-mail at vince(L-tnwtraffex.com or larry@nwtraffex.com. Very truly yours, Vincent J. Geglia Principal TraffEx Page 5 as: "02 Larry D. Hobbs, P.E. Principal TraffEx TABLE 1 PM PEAK HOUR LEVEL OF SERVICE SUMMARY WILSON PARK PLAT TRAFFIC IMPACT ANALYSIS INTERSECTION EXISTING 2014WITHOUTI PROJECT 2011 WITHIPROJECT Site Access SVS 55th St. I - NA- B 10.4 SB B 10.5 SB XX Number shown is the average control delay in seconds per vehicle for the minor approach for unsignalized intersections, which determines the LOS for intersections per the Transportation Research Board Highway Capacity Manual 2000 B Indicates calculated level of service SB (Southbound) Indicates direction of the minor approach for unsignalized intersections Page 6 w LE 5,905+/-S0. ff, 5,5604/ -Sy FT, s ' IN LOT 2 tG`. I 5,905+f -S}. R. LOT LITT 1 » 5,77ZE.sI243i 5 5 MOA, LOT 10 n 6,779+f-50. SSiH AVE. SOUTH ror.w Wilson Park Division 2 Plat - City of Renton Site Plan Figure 1 i 1 rlM ES AN-.wv .71707'_ _--"- I - 1 L -PO ' l a-zz x RACY A y 5,9094/-99,i1. i 7 fol.ft' rY LOT 6 5585+/ -SA FS. \ 1 4 taxsr bio i w LE 5,905+/-S0. ff, 5,5604/ -Sy FT, s ' IN LOT 2 tG`. I 5,905+f -S}. R. LOT LITT 1 » 5,77ZE.s I243i 5 5 MOA, LOT 10 n 6,779+f-50. SSiH AVE. SOUTH ror.w Wilson Park Division 2 Plat - City of Renton Site Plan Figure 1 NL7R7-H1YE5'T TRA rric Ex,-,rp ns i SE MTO ST F SEMN ST ss a r MM it i NTH ST M j sO.Ow sr t Future Project Future Without Generated With Existing Project Trips Project 0-,J k 0 468-121 6 JJ - 2 140 5 J ` 1 0'0`0 11-1 ` 3 544-0-340540 Wilson Park Division 2 Plat - City of Renton Figure PM Peak Hour Volumes for Existing and Future Conditions 2 TECHNICAL APPENDIX TWO-WAY STOP CONTROL SUMMARY General Information Site Information nal s1 enc /Co. Date Performed 6/19/2009 Analysis Time Period IPMpeak East/West Street: S 55th St 7 5 intersection Orientation: East-West Volume Vehicle Volumes and Adjustments Major Street 0.93 Eastbound Movement 1 2 Percent Grade (%) L T olume 6 540 eak-Hour Factor, PHF 0.93 0.93 Hourly Flow Rate, HFR 6 580 Percent HeavyVehicles 0 Median Type RT Channelized Lanes 0 1 onfi uration LT stream Signal 0 Minor Street Northbound Movement 7 5 L Volume 0 Peak -Hour Factor, PHF 0.93 Hourly Flow Rate, HFR 0 Percent Heavy Vehicles 0 Percent Grade (%) RT Channelized Lanes Configuration Dela. Queue L ration km) tvpn) c 5% queue leng Control Delay LOS Approach Delay Approach LOS 1-- and Level of EB 1 LT 6 1441 0.00 0.01 7.5 A WB 4 Intersection 5 Jurisdiction T Renton Analysis Year 2 2014 Future Without Project 0.93 150 2 North/_South Street: Site Access St 5tudv Period (hrs): 0.25 Illllllllii Northbound 7 8 9 Istbound 5 6 T R 140 2 0.93 0.93 150 Northbound 7 8 9 Istbound 5 6 T R 140 2 0.93 0.93 150 2 0 a HCS2000 Copyright C, 2000 University of Florida, All Rights Reserved Version 4.1 c r 0 Southbound 0 0 0 0 II II HCS2000 Copyright C, 2000 University of Florida, All Rights Reserved Version 4.1 c TWO-WAY STOP CONTROL SUMMARY General Information Site Information Co. Performed Analysis Time Period Project Description 6/1912009 PM peak Intersection urisdiction Analysis Year Renton 2014 Future with Project East/West Street: S 55th St North/South Street: Site Access St Intersection Orientation: Fast -West IStudy Period hrs : 0.25 Vehicle Volumes and Adjustments Major Street Eastbound Westbound Movement 1 2 3 4 5 6 L T R L T R Volume 11 540 0 0 140 3 Peak -Hour Factor, PHF 0.93 0.93 0.93 0.93 0.930.93 Hour! Flow Rate, HFR 11 580 0 0 150 3 Percent Heavy Vehicles 0 0 Median Type Undivided RT Channelized 0 0 Lanes 0 1 0 0 0 Configuration LT TR Upstream Signal 0 0 Minor Street Northbound Southbound Movement 7 8 9 10 11 12 L T R L T R Volume 0 0 0 2 0 6 Peak -Hour Factor, PHF 0.93 0.93 0.93 0.93 0.93 0.93 Hourly Flow Rate, HFR 00 0 1 0 2 i 0 6 Percent Heavy Vehicles 0 0 0 0 0 0 Percent Grade (°1°) 0 0 Flared Approach N N Storage 0 0 RT Channelized 0 0 Lanes 0 0 0 0 0 0 nfiguration LR Queue Len th, and Level of ServiceDpenay, proach EB WB Northbound Southbound vement 1 4 7 8 9 10 11 12 Lane Configuration LT LR vph) 11 8 C (m) (vph) 1440 668 Ic 0.01 0.01 5% queue length 0.02 Q.04 ontrol Delay 7.5 10,5 LOS A g 4 Approach Delay 10.5 pproach LOS g HCS2000TM Copyright C 2000 University of Florida, All Rights Reserved Version 4.l c