Abstract
To improve traffic safety at signalized intersections, driver behavior associated with right-of-way transitions at signalized intersections must be quantified carefully. Video data from five intersections across Oregon were collected and transcribed; a total of 149 h corresponded to 3,474 vehicles responding to a circular yellow (CY) indication and 731 vehicles responding to a circular red (CR) indication. A mixed logit model was used to evaluate driver responses to CY and CR indications. Multiple linear regression was used to analyze the characteristics of red light runners (RLRs). Sufficiency of the red clearance interval was evaluated by considering the interactions of RLRs with vehicles on the conflicting approach. Developed models indicated that a 1-s increase in red time per cycle decreased the probability that a car would stop in response to a CY indication (by 41.4%) or a CR indication (by 9.0%). However, an increase in red time decreased the required duration of the red clearance interval. A 1-s red clearance interval generally was adequate for passenger cars, light trucks, and trucks at intersections up to 80 ft wide and at intersections with a red time of at least 60 s per cycle but rarely was sufficient for semitrailers in wider intersections with shorter red times. This observation is critical because semitrailers were more likely to be RLRs than were other vehicle types.