SR 05:276 - Laserfiche WebLink

City Staff has again analyzed traffic circulation adjacent to Neal School with updated versions of the traffic simulation software with similar results to the original analysis. A traffic signal at this location would result in traffic back-ups beyond the Fire Station during the morning Peak Hour. The roundabouts result in less queuing and smoother traffic flow at the school, and 25 to 30 MPH speeds adjacent to the school. Staff then looked at the effect various changes to traffic volume projections or intersection lane configurations would have on traffic congestion at this intersection. This included assuming reductions in westbound left turn volumes, through volumes and roadway widenings to provide long double left turn lanes. In all cases, the roundabouts outperformed a traffic signal in terms of reduced stopped delay, significantly shorter traffic backups to the east of the intersection, and reduced speeds adjacent to the school. Staff fmds that the roundabouts appear to result in the least congestion and ideal travel speeds near the future school site along Vineyard Avenue. With the school entrance on the south end of the school site adjacent to the Old Vineyard multi-purpose trail, there are no school-related pedestrian or bike issues at the roundabouts. Vineyard A venue would have to be widened significantly east of the intersection, and increased bus and carpool use would be necessary from Ruby Hill to the school for a traffic signal to work effectively at this intersection. The need for the traffic signal in the Specific Plan and the roundabouts that were built to replace the signal were primarily triggered by plans to build an Elementary School on this site. If pending court decisions result in the school not being built and the land use changes such that significantly less peak hour traffic is generated by the site, the need for the roundabouts would need to be re-evaluated. If the school site were converted to low density housing, 1- way stop sign control would probably suffice at each intersection in place of the roundabouts as traffic volumes would not be sufficient to meet the requirements for installation of a traffic signal. Without the school, another option would be to build a road within the tract that links the two side streets. This would allow one of the intersections to be eliminated, and concentrate all residential traffic at one signalized intersection along Vineyard Avenue. Vineyard Avenue would have to be widened to create left and right turn pockets Some residents have complained about the need to slow down at the roundabouts while the school has not been built and little traffic is using the side streets. There have also been incidents where large trucks have become stuck in the roundabouts while trying to make u- turns. The residents using the side streets have complained that Vineyard Avenue traffic fails to yield to them properly. A few vehicles have run off the road at the roundabouts due to inattention, or driving under the influence. Staff discussed making the roundabouts 20 feet larger during the design of the project. However larger roundabouts would have taken some land away from the school site and properties on the other two corners. Large, high speed roadway circles known as rotaries SR:05:276 Page 5 of 9