To: From: Matt Folden, AICP, MNCPPC Rebecca Torma, MCDOT Nancy Randall, AICP, PTP Barbara Mosier, P.E., PTOE Kevin Berger 1110 Bonifant Street Suite 210, Silver Spring, MD 20910 301-448-1333 WellsandAssociates.com Re: Westwood Properties Traffic Signal Warrant Study and Operational Analysis Montgomery County, Maryland Date: June 15, 2018 INTRODUCTION This memorandum provides the results of a traffic warrant study for the future realigned Westbard Avenue and Ridgefield Road intersection, the future Westbard Avenue and North Site Access intersection, and the future Westbard Avenue and South Site Access intersection located in the Bethesda Chevy Chase Policy Area of Montgomery County, Maryland. This signal warrant study is an update to the submitted signal warrant study dated March 22, 2017 to reflect a revised development program and access configuration, as well as additional supplemental analysis requested during the LATR scoping and review process. The purpose of this analysis is to determine if (1) the existing traffic signal at the intersection of Westbard Avenue and Ridgefield Road will still be warranted with the proposed reconfiguration of this intersection and the redevelopment of the Westwood Properties, and (2) if the future Westbard Avenue and future New Street A North Access intersection and future Westbard Avenue and future New Street A South Access intersection will meet the warrants for signalization with the redevelopment of the Westwood Properties. Sources used to complete this study include the guidelines contained in the Manual on Uniform Traffic Control Devices (MUTCD), 2009 Edition; Institute of Transportation Engineers (ITE) Trip Generation Manual, 10 th Edition, existing vehicular traffic counts collected by Wells + Associates (W+A) on May 17, 2018; and the distributions contained in the Westwood Properties LATR/TPAR prepared by W+A dated June 14, 2018. The Traffic Engineering Applications Package (TEAPAC) computer program was used to evaluate the MUTCD warrants.
BACKGROUND The existing Westwood property comprises five (5) parcels and contains 481,486 square feet (S.F) of mixed use development. The existing structures, with the exception of the Westwood Towers (HOC) and Bowlmor, will be razed and replaced with a mixed use development that will be built in two (2) phases. The proposed development plan is shown in Figure 1. Westwood, when constructed, will consist of the following mix of uses: Phase I Land Use Total Mid Rise Apartments (D.U) 190 Townhouses (D.U) 72 Retail (S.F) 127,480 Restaurant (S.F) 42,494 Office (S.F) 5,074 Phase II Land Use Total Mid Rise Apartments (D.U) 220 Townhouses (D.U) 34 Retail (S.F) 5,000 This analysis also considers the master planned realignment of Westbard Avenue and the reconfiguration of the Westbard Avenue & Ridgefield Road intersection. At the buildout of the project (i.e. at the end of construction of Phase I and Phase II), site access will be provided at four (4) locations along Westbard Avenue. The location of the proposed site and study intersections are also shown in Figure 1. ROADWAY NETWORK Westbard Avenue is a four lane roadway that extends from MD 190 (River Road) south to MD 396 (Massachusetts Avenue). The redevelopment of the Phase II parcels is designed to facilitate the Master Planned realignment of Westbard Avenue between Ridgefield Road and MD 190 and reconfiguration the Westbard Avenue/Ridgefield Road intersection. These improvements will result in a three legged intersection with Westbard Avenue operation as the major street. 2
WELLS + ASSOCIATES Transportation Consultants INNOVATION + SOLUTIONS WESTBARD AVENUE RIDGEFIELD RIVE R RO AD ROAD WESTBARD 1 AVENUE 2 WESTBARD AVENUE SITE RIDG EFIE SITE LD R OAD 2 ACCESS #1 ACCESS #1 FORT SUMMER DRIVE W 3 TB AR D AV WESTBARD ES AVENUE V:\PROJECTS\10632 WESTBARD-LATR\GRAPHICS\GRAPHICS\6.13.2018 SIGNAL WARRANT GRAPHICS.DWG 1 SITE EN UE 3 ACCESS #4 JCP Westbard Properties Montgomery County, Maryland WESTBARD AVENUE Figure 1 Study Intersections Existing Lane Use and Traffic Controls Represents One Travel Lane Possible Signalized Intersection Stop Sign NORTH
EXISTING CONDITIONS Traffic Counts Turning movement traffic counts were collected by W+A during a 13 hour period on Thursday, May 17, 2018 at the intersection of Westbard Avenue/Ridgefield Road between the hours of 6:00 AM and 7:00 PM. The traffic counts and summary of the hourly traffic volumes are included in Appendix A. FUTURE CONDITIONS The anticipated site trip generation was calculated based on the ITE Trip Generation Manual, 10th Edition rates for the average daily trips (ADT). This analysis, specifically, considers the trips generated from the proposed land uses. The site trip generation is summarized in Table 1. In order to forecast the number of site trips for each of the 13 hours evaluated consistent with past accepted practices, W+A applied hourly diurnal rates to the daily vehicle trip estimates. The average daily trips were apportioned over the 13 hour period for the proposed Retail, Residential, Restaurant (High Turnover sit down & Quality), and Office uses. The diurnal rates used in this study were obtained from the ITE Trip Generation Manual, 9 th Edition rates, the ITE Journal, and previously approved W+A studies. For the purposes of this traffic signal warrant analysis, future traffic forecasts were developed generally based on the development plan outlined in the Westwood Properties LATR/TPAR. The future lane use and traffic controls for the three (3) study intersections are also shown Figure1. As previously noted, the study considers the reconfiguration of the future Westbard Avenue and Ridgefield Road intersection which will result in a T intersection. This reconfiguration required the redistribution of the existing traffic, including the removal of the cut through traffic to and from River Road via Westbard north of Ridgefield Road. The trips generated from the existing residential development along the existing Westbard Avenue were reassigned through the reconfigured intersection. The redistributed traffic volumes are included in Appendix A. 4
Table 1 Westwood Properties Proposed Trip Generation Phases I and II Land Use ITE Land Use Amount Units ADT Code External Trips Phase I Retail MNCPPC 127,480 SF 7091 Office MNCPPC 5,074 SF 59 High Turn Over Sit Down Restaurant 932 21,247 SF 2383 Quality Restaurant 931 21,247 SF 1781 Apartments 221 190 D.U 1034 Townhomes MNCPPC 72 D.U 503 Total Proposed Trips (Phase I) 12,851 External Trips Phase II Apartments 221 220 D.U 1197 Townhomes MNCPPC 34 D.U 216 Retail New Trips MNCPPC 5,000 SF 189 Total Proposed Trips (Phase II) 1,602 Total Proposed Trips (Combined Phases I and II) 14,453 Note: 1. Trip generation basd on rates and/or equations as published in the ITE Trip Generation Manual, 10th Edition.
The trips shown in Table 1 were then adjusted to account for internal trip making between the mixed uses on site and to account for pass by trips ingressing and egressing the proposed retail and restaurant land uses. A summary of the process used to calculate the 13 hour distribution of the site trips is provided below: 1. For Phase I, convert vehicular trips to total person trips using the anticipated average auto occupancies listed below: Residential uses 1.56 persons per vehicle during AM peak, 1.7 persons per vehicle during PM peak. Office uses 1.3 persons per vehicle during AM peak, 1.32 persons per vehicle during PM peak. Retail uses 1.31 persons per vehicle during AM peak, 1.43 persons per vehicle during PM peak. Quality Restaurant uses 1.78 person per vehicle High Turnover Sit Down Restaurant 1.52 persons per vehicle 2. For Phase I, determine the number of internal walking trips based on methodologies and internal person trip capture rates for trip origins within a mixed use development presented in ITE s Trip Generation Handbook, 3rd Edition (2014). 3. For Phase I, determine the number of external person trips by subtracting the internal walking trips from the total person trips. 4. For Phase I, convert the external person trips back to external vehicle trips by applying the average auto occupancy rates listed above. 5. Determine the number of pass by trips anticipated based on pass by percentages obtained from ITE s Trip Generation Handbook, 3rd Edition. These percentages are listed below: Retail uses 34% PM peak hour only High turn over sit down restaurant uses 43% PM peak hour only Quality restaurant 44% PM peak hour only. 6. The external vehicle trips and pass by trips for each land use were then assigned to the study intersections based on the planned land use of each phase and proximity to each site access. The calculations and assumptions described above are included in Tables 1B 7B located in Appendix B. The trips were distributed to the road network based on the distributions for residential and commercial uses presented in the Westwood Properties LATR/TPAR dated June 14, 2018. The total future forecasts are a combination of the existing counts, reassigned volumes, and the 13 6
hour forecasts for each phase for residential, commercial, and commercial pass by volumes. The 13 hour forecast for each use and the total forecast worksheets are shown in Tables 1C 39C, located in Appendix C. SIGNAL WARRANT ANALYSIS The intersection signal warrant analyses were conducted using the warrants for signalization contained in the Manual on Uniform Traffic Control Devices (MUTCD), 2009 Edition using the 13 hour traffic forecasts discussed above. Based on previous correspondence with MCDOT, this study only considers the requirements outlined in Warrant 1 (1A, 1B, and 1C) for the installation of a new signal. An evaluation of the MUTCD guidelines was prepared based on the 13 hour traffic count data and roadway geometry using TEAPAC. The results of the TEAPAC analysis are presented in Appendix D and are summarized in Table 2. Future Westbard Avenue and Ridgefield Road. Warrant 1A: NOT MET Warrant 1B: NOT MET Warrant 1C: NOT MET Future Westbard Avenue and Future Street A North Access Warrant 1A: NOT MET Warrant 1B: MET Warrant 1C: NOT MET Future Westbard Avenue and Future Street A South Access With Only Phase I Warrant 1A: MET Warrant 1B: MET Warrant 1C: MET With Both Phases I and II Warrant 1A: MET Warrant 1B: MET Warrant 1C: MET 7
Table 2 Westwood Properties Traffic Signal Warrants Summary (1) Total Future Conditions (with Buildout of Phases I and II) Total Future Conditions (with Phase I) Total Future Conditions (with Buildout of Phases I and II) Warrant Warrant Description Requirements Westbard Avenue/Ridgefield Road (Realignment) Future Westbard Avenue/ Future Street A North Access Future Westbard Avenue/ Future Street A South Access 1 A 8 Hour Minimum Vehicular Volume 8 hours 0 hours Not Met 0 hours Met 8 hours Met 8 hours Met 1 B 8 Hour Interruption of Continuous Traffic 8 hours 4 hours Not Met 8 hours Met 8 hours Met 9 hours Met 1 C 8 Hour Combination of Warrants Not Met Not Met Met Met Notes: (1) Warrant summary based on TEAPAC Complete 2010 (Version 8.61, Build 1) 2009 MUTCD Warrant Analysis Analysis Results Warrant Results Analysis Results Warrant Results Analysis Results Warrant Results Analysis Results Warrant Results
CONCLUSIONS AND RECOMMENDATIONS The conclusions and recommendations of this traffic signal warrant evaluation are as follows: 1. A traffic signal will not be warranted at the intersection of Future Westbard Avenue and Ridgefield Road, with the proposed reconfiguration of this intersection to a T intersection and with the proposed redevelopment of the Westwood Properties. Based on the evaluation of this signal warrant study, the existing traffic signal should be removed when the intersection is redesigned. 2. The proposed traffic signals for the Future Westbard Avenue/Future Street A North Access and Future Westbard Avenue/Future Street A South Access intersections are warranted under total future conditions with the redevelopment of the Westwood Properties. Based on the analysis contained in this report, the installation of traffic signals is recommended for these two (2) intersections. 9
OPERATIONAL ANALYSIS An operational analysis was conducted for Westbard Avenue with the redevelopment of Westwood Properties. This analysis assumes the installation of two new traffic signals and the realignment of Westbard Avenue and Ridgefield Road with a redesigned traffic signal. This analysis evaluates the queuing along Westbard at the study intersections. A 90 second cycle length was assumed for the two new traffic signals and the realigned intersection of Westbard Avenue/Ridgefield Road. Two time periods were analyzed: the AM and PM peak hours. The intersection of MD 190 (River Road) and Ridgefield Road has a variable message signage at the northbound approach that changes lane use during the PM peak period. The 95 th percentile queues were calculated using Synchro 9 software. The results are summarized in Table 3, and worksheets are also provided in Appendix E. Queues at the intersection of Westbard Avenue and River Road will exceed 80% of the storage distance for the northbound left during the AM and PM peak hours as well as for the northbound throughleft movement during the PM peak hour. At the realigned intersection of Westbard Avenue/Ridgefield Road, queues will exceed 80% of the storage distance on the eastbound left during the AM peak hour. Queues are expected to be accommodated by the available storages provided for the turning movements of the remaining intersections. For the purpose of this analysis, the lane use for the northbound approach of Westbard Avenue at River Road in the PM peak period was considered as a possible road improvement for the AM peak period. The results show that the 95th percentile queues for the northbound movements would be generally accommodated during the AM and PM peak hours. With signal timing changes along the Westbard Avenue corridor along the site frontage to the intersection of Westbard Avenue and River Road, the queues on Westbard Avenue could be reduced. Based on the information provided, with PM peak hour lane use on the northbound approach was permitted throughout the day, and with modifications to the signal timing at the intersection of Westbard Avenue and River Road, the redevelopment of Westwood Shopping Center will not cause excessive queues along Westbard Avenue. SUPPLEMENTAL HCM CAPACITY ANALYSIS Based on request from MNCPPC staff during the scoping process, a full HCM analysis of the LATR study area as also performed using Synchro 9 software. The peak hour traffic volumes for existing, background, Total Future Phase I, and Total Future Build out both with and without the realignment, as contained in the June 14, 2018 LATR study were evaluated using the Synchro software. The resulting HCM printouts are contained in Appendix F for reference. 10
Table 3 Westwood Properties 95th Percentile Queue Summary 1,2 Intersection Operating Condition Approach/ Movement Available Storage 80% Storage Distance AM Total Future Conditions Does queue exceed PM storage? Does queue exceed storage? 1 River Road/Future Westbard Avenue Signal NBL 310 248 387 YES 295 YES NBLT 310 248 57 298 YES NBR 310 248 71 161 Potential Improvement: Signal NBL 310 248 214 Assume PM peak northbound lane use in AM peak NBLT 310 248 214 NBR 310 248 71 2 Westbard Avenue/Ridgefield Road (Realigned) STOP EBL 80 64 33 18 EBR 80 64 14 8 NBL 120 96 2 8 3 Future Westbard Avenue/Future Street A North Access Signal NBLTR 270 216 34 92 SBLTR 200 160 52 155 4 Future Westbard Avenue/Westwood II Access 2 Stop NBLTR 240 192 0 0 SBLTR 280 224 0 2 5 Future Westbard Avenue/Future Street A South Access Signal NBLTR 290 232 58 209 SBLTR 260 208 41 232 YES 6 Future Westbard Avenue/Westwood Shopping Center Driveway STOP SBTR 280 224 0 0 Notes: (1) 95th percentile queues derived using Synchro 9 software. Queues and storage lengths in units of feet. (2) Assumes Westbard Avenue as a north/south roadway at all intersections.