Use of Median U-Turns to Improve Traffic Flow Along Urban Arterials.

The increased traffic congestion along urban arterials has prompted the need to examine and implement innovative ways to accommodate the traffic. Some potential alternatives are the use of unconventional left turn treatments, prohibition of left turns at the intersection, and rerouting of them at a U-turn point beyond the intersection. This study examined the implementation of median U-turns along an urban principal arterial in Lexington, Kentucky. Traffic simulation was utilized to evaluate different alternatives including signal optimization, addition of through traffic lanes, and implementation of median U-turns in two stages. Based on the analysis, median U-turn strategies proved to be a more efficient tool for traffic management along this arterial than simply adding a lane in each direction. The median U-turns showed significant improvements in all operating measures of the arterial and average delay was the measure that improved the most at all intersections. Reducing delays by 25% and peak hour travel times by 15% are achieved without adding new lanes. Instead of initiating a costly construction program, traffic can be controlled in an innovative manner that makes better use of the existing infrastructure. [ABSTRACT FROM AUTHOR]