Research of efficiency evaluation of U-turn lanes at Signalized Intersections

Abstract

This research categorized U-turn at Signalized Intersections into mainly four modes, designating them as Mode A,B,C,D: Mode A, at the Downstream Section of the Stop Line; Mode B, at Upstream Section of the Stop Line; Mode C, at the Right Side of the Ingress; Mode D, at the Upstream Section of the Transition Zone. We first evaluate their respective efficiency level, and then set up an efficiency evaluation index system. Three indexes, saturation of left turn lane, average queuing length and average delay of signal control, are standardized by modeling and simulating. The AHP method is then applied to study the integrated index for U-turn evaluation on efficiency. After theoretical arithmetic and simulating, the result shows that Mode D shows a significant advantage considering efficiency factors in each condition. This research may support urban traffic design both theoretically and technically.