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HomeMy WebLinkAboutC_memoResponsetranspo_200706.pdfWilliam Popp Associates Transportation Engineers/Planners ________________________________________________________________________ (425) 401-1030 (425) 401-2124 e-mail: info@wmpoppassoc.com 14-400 Building Suite 206 14400 Bel-Red Road Bellevue, WA 98007 MEMORANDUM TO: Andy Loos, Project Manager of Cedar River Apartments Project FROM: William Popp, P.E. DATE: July 6, 2020 SUBJECT: Responses to Cedar River Apartments Traffic Impact Analysis Review Comments dated April 29, 2020 This is in response to the April 29 letter from the Transpogroup/Jon Pascal to the City of Renton/Matt Herrera addressing our February 18, 2020 Updated Cedar River Apartments Traffic Impact Analysis. The comments are in boxes and our responses follow unboxed. 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. Acknowledged. As noted, the analysis results should not be affected. 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? For mixed occupancies on the same lot, the RMC states: “The total requirements for off- street parking facilities shall be the sum of the requirements for the several uses computed separately, unless the building is classified as a “shopping center” as defined in RMC 4-11-190.” The proposed development only proposes three different commercial uses, with residential comprising the majority of gross square footage on the site, and would not be classified as a “shopping center.” The total off-street parking provided on the lot exceeds the minimum parking required for the combined uses. We have revised Memo to: Andy Loos, SRM Development Cedar River Park Apartments July 6, 2020 William Popp Associates the TIA to reflect that there would not be a shortage of parking for the medical office building. The 48 surface stalls (Phase 1 and 2) will be constructed prior to the medical office building (Phase 3). To clarify this issue, a line has been added to Table 12 Phase 1 Building A Supply column referring to the 41 stalls that says “to be used for Building C.” Once the medical office building is constructed in Phase 3, notification to residents would be provided and signage would be installed specifying that use of the surface lots are reserved for the medical office building. In addition a paragraph is proposed for addition to the narrative on Page 48 that says “ As suggested by the foregoing, the King County Right Size Parking Calculator (for multi- family residential) and the ITE Parking Generation 5th Edition are considered the more reliable demand predictors of parking use for this site. Data supporting the parking requirements of the RMC are unavailable for scrutiny whereas the King County source represents relatively recent local data with important selection parameters and the ITE source for Medical Office Building is derived from some 117 searchable data points with excellent statistical validity for the prediction equation”. 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? We concur that the more effective method of preventing left turns in and out of the driveway is with a relatively short TWLTL C-curb addition, or alternatively with tubular markers as have been placed on SR 169 just west of the Jones Road intersection. And this in turn suggests the proposed raised markings definition of the pork chop island would be an optional consideration. With the tubular markers option, the pork chop island would not be needed to address the possibility that the C-curb may not be visible to exiting motorists during periods of poor visibility or snow. The original Transpogroup comment was mistakenly assumed to refer to the pork chop island and not the two-way left turn lane as the solution focus. The pork chop island was recommended to deter left turns in and out while allowing the occasional right turning truck to make the narrow lane right-in or right-out movement using the mountable design. And yes, adding the C-curb to the TWLTL will require the WSDOT channelization plan Memo to: Andy Loos, SRM Development Cedar River Park Apartments July 6, 2020 William Popp Associates approval process and was a factor in the recommendation but in retrospect that process will be required anyway for the proposed signal modifications at the Cedar River Park Drive intersection with SR 169. So the two actions could be part of the same application and the process issue is thus moot. These alternative considerations will be addressed with WSDOT during the channelization plan approval process. Truck access is of course available via the main entrance roadway.