SR 05:276 - Laserfiche WebLink

were not considered at these locations. Not only would they have required significantly more land, but studies show that the high speeds lead to more serious collisions. The federal design guidelines for roundabouts were specifically intended to increase safety by reducing the size of circular intersections, and many East Coast rotaries have been replaced by much smaller roundabouts for these reasons. Overall, roundabouts tend to improve traffic safety by virtually eliminating serious right-angle collisions. It is not uncommon for the main street traffic at roundabouts to fail to yield to side street traffic where side street traffic volumes are very low. With the grading of the surrounding land for home construction, and the eventual construction of the elementary school, this problem should be temporary. The roundabouts are not a perfect traffic control device and have their own limitations, just as do stop signs and traffic signals. But, with the school and homes planned in the Specific Plan area, the roundabouts are the best way to control traffic circulation and speeds near the school unless the City decides to significantly widen Vineyard Avenue and the school's west side street to accommodate the heavy left turn movements at the school. The following is a summary of the various options for removing the roundabouts: Option I: Leave roundabouts in place Pros: . Least expensive option. . Provides maximum flexibility for future decision after a decision has been made on the school. . Slows speeds of traffic on Vineyard Avenue. Cons: . Possible confusion of motorists traveling Vineyard Avenue. . Accident could block emergency vehicle response. . Difficulty of traffic entering from side streets. Option 2: Remove roundabouts and install stop sign control on side streets Pros: . Eliminates confusion of drivers on Vineyard Avenue. Cons: . $180,OOO estimated cost today, with future additional costs if school built. . Increase of speeds on Vineyard Avenue. . Difficulty increases for side street traffic to enter Vineyard Avenue. Option 3: Remove roundabouts and install a traffic signal at easternmost location Pros: . Eliminates confusion of drivers on Vineyard A venue. . Improves side street access to Vineyard Avenue. SR:05:276 Page 6 of9