Midblock U-Turn and Elevated U-Turn Safety and Economy Comparison: A Case Study Application

Abstract

In Egypt, intersections are encountering congestion and safety problems. Midblock U-turns have been used for solving these problems. The midblock U-turn increased the accidents, besides, it has limited capacity. In the last decade, elevated U-turns have been applied to solve these problems. The extensive use of elevated U-turns has not been accompanied by any research for studying the performance of elevated U-turns with respect to safety and economy. This paper developed a simple framework for comparing elevated and traditional midblock U-turns in terms of safety and economy. The study applied a case study to evaluate the two alternatives using a benefit-cost analysis technique. Although the results show the high cost of the elevated U-turns, it has been demonstrated to be the best solution since they provide the greater traffic capacity and lower accident rates. Accident number reported at elevated U-turns was 59 % less than the number associated with traditional U-turns.

Keywords

• safety performance function
• crash modification factor
• empirical bayes
• u-turn
• before-after study