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1 and other necessary jurisdictional approval. The goal of this phase is to finalize the geometric alignments and develop a conceptual plan for the City review and presentation to the community by performing the B 11 1 following work: Geometric Refinements — The Project site is isolated to two distinctive areas on either side of the I- 680 /Bernal Avenue Interchange. I -680 Northbound Bernal Avenue On -ramp For the I -680 NB Bernal Avenue on- ramp, \ _ -I ^u there are two potential methods to increase • ._ " ,::�aaccc capacity for the right turn movement. I- , ' � � One alternative would be to construct a pork . _ chop island on the northeast corner of the s ‘ - . intersection to create a free right turn lane , onto the on ramp. This would increase the i capacity of the right turn lane because right . turns would no longer be required to yield to $ eastbound left turns and northbound 0 ‘4t r ' c `s. \ = through movements. However, the right turn volume is projected to be over 1500 i ' '' ' ± . vehicles per hour under cumulative %,, ` ` s 2 conditions, which would approach the : 4� f . ,r 'rr ' ' capacity of a single right turn lane In 4r addition, fora single right turn lane, the �• queues would back up several hundred feet II. ai � r`` - N. `11, ti," '` *. on Bernal Avenue through the intersection of Koll Center Drive. The long queues would inhibit coordinated signal operations in the area, and potentially result in undesirable weaving activity on westbound Bernal Avenue. Lastly, crosswalks spanning free right turns are difficult for pedestrians to negotiate when heavy conflicting traffic is present and Caltrans is currently requesting that pork chop island within project sites be removed due to pedestrian conflicts. A better alternative to improve westbound right turn operations would be to maintain the existing right • turn pocket, but convert the right -most through lane to a shared right- through lane. According to level of service calculations under cumulative conditions (with the planned Safeway development on the Bernal property), the intersection would improve from LOS F without two right turn lanes to LOS D with two right turn lanes. This improvement would also provide a better distribution of traffic volumes across the approach lanes on Bernal Avenue, which helps to reduce the westbound to northbound right turn queues on Bernal Avenue. BKF believes that the dual right turn alternative would likely emerge as the preferred alternative. The key for designing dual right turn movements would be to insure that an interstate STAR truck could negotiate the turn from the outside lane while there is a passenger vehicle on the inside lane. This would . require applying turning templates at the corner. It is likely that an existing traffic signal pole and mast arm would need to be relocated or replaced on the northeast corner to accommodate the dual right turn movement. Widening would likely occur both at the northeast corner of the subject intersection and also along the west side of the northbound on ramp. There appears to be adequate right of way to accommodate the widening. It does not appear the widening would create any alignment issues with other movements at the intersection. Field inspection shows that none of the curb ramps at the intersection have truncated dome panels. This upgrade is recommended in conjunction with the Project. In addition, there is an existing pedestrian barricade on the northwest corner that is damaged (hit by a vehicle) and would be replaced as part of the proposed improvements. Widening to the west is recommended versus widening to the east to avoid an existing power pole which would have to be relocated with an eastern widening. The desire to widen the NB on -ramp to provide two lanes requires that a two lane to one lane merge be