13 ATTACHMENT 11 - Laserfiche WebLink

Josh Pack November 10, 2009 Page7of8 FFlll: & I'LIi R > IRM.SVOVI„II0'I (O'01lt1APII The average vehicle queue at the Bernal Avenue /I -680 Southbound Ramp intersection with the Proposed Project are contained within the available storage, except for the westbound left -turn movement from Bernal Avenue to southbound 1 -680 during the AM peak hour, where the average vehicle queue exceeds the available storage. The 95th percentile vehicle queue also exceeds the available storage for this movement during both the AM and PM peak hours. At the Bernal Avenue /I -680 Northbound Ramps intersection, the average vehicle queues are contained within the available storage for all movements during both peak hours. During the AM peak hour, the 95th percentile vehicle queue exceeds the available storage for the eastbound movements by 1 to 2 vehicles. These queues are expected to clear quickly and not degrade intersection operations during the AM peak hour. During the PM peak hour, the 95th percentile vehicle queues are exceeded for the eastbound and westbound locations. While signal timing monitoring and modifications can balance the vehicle queues between movements during the PM peak hour, there will be periods when this intersection will operate at worse service levels than presented in Table 3 due to vehicle queue spillback. At the Bernal Avenue /Koll Center Drive intersection, the average vehicle queues are contained within the available storage for all movements during both peak hours. During the AM peak hour, the 95th percentile vehicle queues are also contained within the available storage. During the PM peak hour, the 95th percentile vehicle queues are exceeded for the eastbound direction of travel by 1 to 2 vehicles. These queues are expected to clear quickly and not degrade intersection operations during the PM peak hour. At the Bernal AvenueNalley Avenue intersection, the average and 95th percentile vehicle queues are contained within the available storage for all movements on Bernal Avenue during both peak hours. Due to the short distance between intersections along the Bernal Avenue project frontage, the heavy right -turn volume for vehicles entering northbound 680 from westbound Bernal Avenue, and the trap right -turn lane for the westbound Bernal Avenue to northbound 1 -580 movement, the potential for vehicle lane change movements was qualitatively evaluated. Generally, vehicle lane change movements would not have a great impact on overall corridor operations, as most drivers though this area either live or work in the vicinity and are aware of the roadway conditions. However, some visitors to the retail component of the Proposed Project may be unfamiliar with the roadway system and could position themselves incorrectly to enter 1 -680, requiring rapid lane changes within a short distance, which could impede general traffic flow. Signal operations of the Bernal Avenue /Koll Center Drive intersection can be timed to allow the westbound right -turn vehicle queue at the northbound ramp intersection to start clearing before the northbound left-turn movement is served. This would allow vehicles exiting the project site destined to northbound 1 -680 to enter the back of the vehicle queue without blocking adjacent travel lanes. However, this signal timing operation does cause some vehicle queuing for the eastbound movements on Bernal Avenue at Koll Center Drive (as shown in Table 4). As the traffic signals at the 1- 680 /Bernal Avenue ramps are under the jurisdiction of Caltrans, the City will work with Caltrans to coordinate traffic signal timing along the Bernal Avenue corridor to minimize vehicle queue spillback through the corridor. The southbound approach of the Koll Center Drive /Bernal Avenue intersection is striped to indicate that vehicles destined for northbound 680 should use the in the outside travel lane. Similar markings and signage could be installed on the westbound approach of the Bernal Avenue /Koll Center Drive intersection as well as for the northbound left -turn movement and southbound right -turn movement at the at the Bernal AvenueNalley Avenue intersection to further direct vehicles to the correct travel lane to minimize lane changes on Bernal Avenue between Valley Avenue and the 1 -680.