Evaluation of Intersection Safety and Capacity Relevant to Signal Timing Design on Arizona's State Highway System

The Arizona Department of Transportation (ADOT) has determined that a comprehensive evaluation of intersection safety and capacity is necessary to address issues with signal timing design. The study is evaluating the current signal timing design with focus on all-red time, yellow change interval and pedestrian clearance interval. The study will compile and analyze state-of-the-practice methods for calculating the all-red times for through-movements, left-turn movements, yellow change intervals, and pedestrian clearance intervals. The main objective of the project will be to develop recommendations for potential updates to the ADOT Traffic Guidelines and Policy (TGP).