Reso13 PC 13-09 2859 Initial Study Mitigated Negative Declaration Kensington

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TJ KM Transportation Consu Itants Left-turn queue lengths on EI Camino Real at the study intersection under Existing plus Proposed Project Conditions were also analyzed for the three peak hours by comparing the 95ih-percentile queue lengths with the left-turn storage length provided. The longest left-turn queues would continue to occur during the p.m. peak hour, when the northbound and southbound queues would remain at approximately I 50 feet and 170 feet respectively with the additional project trips. These 95ih-percentile queues would be accommodated within the available left-turn lane storage lengths of 200 feet northbound and 195 feet southbound. Because intersection LOS would remain acceptable and 95ih-percentile left-turn queues would not exceed the available storage length, no mitigations due to project traffic are necessary at the study intersection. Need for Eastbound Oakwood Drive Right-Turn Lane Based on the peak-hour analysis of the EI Camino Real/Oakwood Drive/Dumbarton Avenue intersection, TJKM evaluated the need for a right-turn lane on eastbound Oakwood Road, which would be precluded by the proposed vacation of an existing easement that had been reserved for such lane. The existing curb-to-curb width of Oakwood Drive at EI Camino Real is approximately 28 feet, and the pavement width tapers down to approximately 23 feet west of the intersection. With the proposed addition of curb, gutter and sidewalk on Oakwood Drive, the curb-to-curb width would be 24 feet near EI Camino Real. With both the existing and proposed width of Oakwood Drive, only one lane is provided for all eastbound traffic whether turning left or right or proceeding straight through the signalized intersection with EI Camino Real. This one-lane eastbound configuration can prevent potential opportunities to turn right on a red signal, because only one vehicle waiting for the green signal to turn left or proceed straight through blocks any vehicles behind it that might otherwise be able to turn right. Table N shows the expected 95ih-percentile queue lengths on eastbound Oakwood Drive approaching EI Camino Real for the three peak hours under Existing Conditions and Existing plus Proposed Project Conditions. As shown in the table,the a.m. peak hour would have the longest 95ih-percentile queue, which correlates with the peak hour intersection LOS and delay results described above. The project's impact on peak-hour queue lengths would be less than significant. Table IV: Eastbound Oakwood Drive — Peak Hour 95t"-percentile Queue Lengths A.M. Peak Hour(feet) School P.M. Peak Hour(feet) P.M. Peak Hour(feet) Existing Plus Project Existing Plus Project Existing Plus Project 208 211 88 96 83 88 During the a.m. peak hour under Existing plus Proposed Project Conditions, eastbound Oakwood Drive traffic movements at EI Camino Real would consist of approximately 95 right turns and 154 combined left-turn and through movements. TJKM tested an alternative configuration for eastbound Oakwood Drive approaching the intersection by assuming a right-turn-only lane and one shared left-turn/through lane. The average delay on the eastbound Oakwood Drive approach would decrease from 36.3 seconds with the existing single lane to 25.3 seconds with the alternative two-lane configuration. The resulting a.m. peak hour queue length in a right-turn-only lane would be less than 30 feet, and the 95ih-percentile queue length in the shared left-turn/through lane would be approximately 140 feet, compared with a queue length of approximately 210 feet with the existing single lane. Dra ft Report— Tra�c Impad Study for Assisted Living Facility Development at 2808 EI Camino Real Page 13 in the City of Redwood City March 12, 2012