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Home My WebLink AboutExh.32_TranspoGroup_Review 12131 113th Avenue N.E., Suite 203, Kirkland, WA 98034 | 425.821.3665 | TG: 1.19297.00 December 2, 2019 Matt Herrera Senior Planner City of Renton 1055 S. Grady Way Renton, WA 98057 SUBJECT: CEDAR RIVER APARTMENTS TRAFFIC IMPACT ANALYSIS REVIEW COMMENTS Dear Mr. Herrera: We have completed our independent review of the October 21, 2019 Traffic Impact Analysis (TIA) prepared by William Popp Associates for the Cedar River Apartment project proposal on behalf of the City of Renton. We recommend the City require an updated TIA in response to the following review comments: Pages 3, 20, Table 6. Trip Generation. The Phasing Plan and Architectural Sheets submitted as part of the application indicate the Medical Office building planned as part of Phase 3 will be a total of 50,000 square feet (two floors of 25,000 sqft), instead of the 25,000 square feet assumed in development of the trip generation estimates. The trip generation estimates in Table 6 and the resulting traffic operations analyses should be updated accordingly. Page 22. Trip Distribution. The distribution of site-generated traffic should be presented following the Policy Guidelines for Traffic Impact Analysis for New Development, May 2013. The City’s guidelines state that the distribution should be presented by direction as a percentage of the total site generated traffic in a graphic format. Include a trip distribution figure to illustrate how the distribution patterns were converted into project trip assignments. Page 23 & 24. Figure 7a & 7b. It appears that the pass-by trips were not included in the figure and the operations analysis. The pass-by trips should appear as adjustments to the turning movement counts at the site access locations. The analysis should be updated to account for the pass-by trips. Page 35. Intersection LOS Analysis. The turning movement volumes for 2023 “With Project” AM and PM scenarios are not consistent for some movements between volume graphics (Figure 8b and 9b) and the Synchro worksheets in Appendix C.1.c and C.2.c. The Synchro and corresponding SimTraffic analysis should be updated to use consistent turning movement volumes shown in the graphics. Page 35. Peak Hour Factor (PHF). The PHF used in the SimTraffic analysis (1.00) is not consistent with the Synchro analysis (0.90). The WSDOT Synchro & SimTraffic Protocol, August 2018, referenced in this analysis only provides guidance on reasonable range of the PHF to use for the Synchro analysis, with no direction for SimTraffic. Without PHF provided for the existing turning movement counts, the future PHF could be estimated based on Table 19 from NCHRP Report 599. The 0.90 PHF should be justified for use in the analysis, or the PHF should be updated to use recommended values from NCHRP Report 599. Additionally, the SimTraffic analysis should utilize the same PHF as the Synchro analysis for consistency purposes. Page 38. SimTraffic Simulation Period. The analysis uses a 30-minute simulation rather than a commonly used 60- minute duration as representation of the peak hour. The SimTraffic analysis should be updated to use a 60-minute period. EXHIBIT 32 DocuSign Envelope ID: 99BA427F-FE67-49CC-B142-9BE0760232C1 Mr. Matt Herrera December 2, 2019 Page 2 Page 38. Table 8. Scenarios Evaluated. A Year 2023 scenario with the Project, but before implementation of the WSDOT ETL project should be evaluated in SimTraffic. The TIA should be updated to include this additional scenario in the SimTraffic results. The updated traffic operations analysis should clearly demonstrate that the trips generated by the Project will be able to be processed by the Cedar River Park Drive intersection during the AM peak hour when the westbound maximum queue on SR 169 extends for nearly 4,500 feet. Page 38. SimTraffic Files. Please provide the actual SimTraffic files so the results can be reviewed more closely. Page 42. Parking. The parking analysis should include information from the Renton Municipal Code (RMC) that identifies the number of stalls required for each of the proposed land uses. It should be specified that for the proposed medical office (Building C), RMC requires 5 stalls per 1,000 net floor area. A table format is recommended to summarize and identify the differences between the parking required by RMC, the estimated parking demand from the King County Multi- Family Residential Parking Calculator, and the proposed parking supply. The table should include the proposed parking supply for each land use, and note key differences from the RMC. In addition, bicycle parking should be provided with specified minimum requirement in RMC. Finally use of the King County Multi-Family Residential Parking Calculator should be justified as a reasonable comparison tool for this specific location. Page 48. Frontage Improvements. The discussion should be updated to identify the specific width allocated for utilities and landscaping behind the sidewalk. Currently no width has been identified. Page 49. Secondary Site Access - Location. The location of the access point should be consistent with the 350 feet described on page 45. In addition, the proposed location of this access point is where the 3-lane section of southbound SR 169 transitions to a 2-lane facility. Drivers in the right most lane would need to pay additional attention to a vehicle in front that may turn into the driveway, while also trying to find a gap to merge left. Locating a driveway in the vicinity could be a potential safety issue due to the multiple vehicular movements taking place. More information should be included about the interaction between the merging vehicles on SR 169 and the site access vehicles. Otherwise, the southbound lane transition may need to be modified to allow for a safe transition. Page 49. Secondary Site Access – Left-Turn Restriction. We are concerned about the proposed mountable “pork- chop” concept as they are not always effective in preventing left-turns in or out. Was the installation of C-Curb considered to restrict the left-turn movements at this location, or some other form of access management? Thank you for the opportunity to assist in this review. Please do not hesitate to contact me at 425.821.3665 should you have any questions about our comments. Sincerely, Transpo Group Jon Pascal, PE, PTOE Principal DocuSign Envelope ID: 99BA427F-FE67-49CC-B142-9BE0760232C1 12131 113th Avenue N.E., Suite 203, Kirkland, WA 98034 | 425.821.3665 | TG: 1.19297.00 April 29, 2020 Matt Herrera Senior Planner City of Renton 1055 S. Grady Way Renton, WA 98057 SUBJECT: CEDAR RIVER APARTMENTS TRAFFIC IMPACT ANALYSIS REVIEW COMMENTS Dear Mr. Herrera: We have completed our independent review of the updated February 18, 2020 Traffic Impact Analysis (TIA) prepared by William Popp Associates for the Cedar River Apartment project proposal on behalf of the City of Renton. In addition, we reviewed the Responses to Comments Memorandum regarding Transpogroup/Jon Pascal and City Comments, and the associated Synchro/SimTraffic simulation model files that were provided and which supported the updated TIA findings. In general, the updated TIA has helped to address most of our comments, but we still have questions about the following items. Updated TIA (February 18, 2020) Page 35. Intersection LOS Analysis. The turning movement volumes for 2023 “With Project” AM and PM scenarios are not consistent for some movements with pass-by volumes between volume graphics (Figure 8b and 9b) and the Synchro worksheets in Appendix C.1.c and C.2.c. However, the difference is within 1 or 2 trips and should not affect the analysis results and findings. Pages 49 and 54, Parking. The updated TIA shows that the estimated medical office parking demand of 81 vehicles would be adequately accommodated with the 60 designated garage stalls plus the 48 surface stalls. The study also highlighted on Page 49 that there is a shortage of 17 stalls to meet the RMC requirements for this specific use. The study should include more discussion about how the deficiency of 17 stalls will be accommodated, or why it is unnecessary to meet the RMC parking requirement. In addition, it is unclear whether all 48 surface stalls would be available for shared parking. What requirement will be made to ensure adequate spaces will be made available for visitors of the medical office building? Responses to Comments Memorandum Page 4. Response to Comments on Secondary Site Access – Left-Turn Restriction. The C-curb, as described in our previous comments, would be along the southern edge of the current two-way left-turn lane (TWLTL) to prevent left-turns in and out of the driveway, rather than providing a pork-chop. We are not sure how a C-curb would prevent larger trucks from entering or exiting a right-in, right-out only driveway, as described in the response. Truck access should be accommodated at the main access roadway. We are still interested in understanding why a c-curb would not be a more effective solution to restrict left-turns in and out of the driveway. Perhaps the reason has to do with the fact that SR 169 is a WSDOT facility, and concurrence on any channelization changes along the TWLTL would been to be approved by WSDOT? DocuSign Envelope ID: 99BA427F-FE67-49CC-B142-9BE0760232C1 Mr. Matt Herrera April 29, 2020 Page 2 Thank you for the opportunity to assist in this review. Please do not hesitate to contact me at 425.821.3665 should you have any questions about our comments. Sincerely, Transpo Group USA, Inc. Jon Pascal, PE, PTOE Principal jon.pascal@transpogroup.com 425.896.5230 DocuSign Envelope ID: 99BA427F-FE67-49CC-B142-9BE0760232C1