Sharif Digital Repository

Left-turn operation is a critical component in the safe and efficient operation of a signalized intersection. The proper type of left-turn phasing results in reduction of traffic delay and number of accidents. A review of the literature indicates that different warrants have been proposed for the installation of the protected left-turn phase; however, there is not a consensus to implement a specific warrant up to the present. In general, the warrants fall into four categories: traffic volume, operational characteristics of traffic, intersection geometrics and accident experiences. Considering the high rate of accidents resulting from left-turn movements at signalized intersections in Iran,...