Novel Stochastic Procedure for Designing Yellow Intervals at Signalized Intersections

Abstract

Driver behavior while approaching high-speed signalized intersections at the onset of a yellow indication varies as a function of many parameters including age, gender, perception-reaction time, and acceptable deceleration levels. This paper develops a novel approach for computing the clearance interval duration that explicitly accounts for the reliability of the design (probability that drivers do not encounter a dilemma zone). Lookup tables are developed to assist practitioners in the design of yellow timings. The approach is demonstrated using data gathered along the Smart Road test facility for dry and clear weather conditions for two approach speeds: 72.4 km/h and 88.5 km/h. Each data set includes a complete tracking of the vehicle every decisecond within 150 m before and after the intersection. A total of 2016 signal stopping records were gathered. Using these data, models that characterize driver perception-reaction times and deceleration levels are developed. Based on these models, lookup table are developed to assist practitioners in the design of yellow timings that reflects the stochastic nature of driver perception-reaction time (PRT) and deceleration levels.