Pedestrians and Left-Turning Vehicles: An Evaluation of Safety Treatments

Pedestrian safety is a growing concern at signalized intersections. Pedestrian-vehicle crashes tend to be less frequent but more severe than crashes involving only vehicles. A pedestrian-vehicle crash has been estimated to cost four times a vehicle-vehicle crash cost on a willingness-to-pay basis. To address pedestrian safety concerns at signalized intersections, treatments can be used to separate pedestrians and vehicles in time and space, improve pedestrian compliance with signal control, or remind drivers and pedestrians to be aware of each other’s presence. The effectiveness of pedestrian safety treatments is often assessed by monitoring trends in pedestrian-vehicle conflicts (as indicated by evasive movements by drivers or pedestrians) and pedestrian compliance (as indicated by pedestrians’ response to the Walk interval). Crash data can be used, but the relative rarity of pedestrian-vehicle crashes must be overcome by observing a long time period or a large number of sites. Conflicts are also more frequent and thus can provide more timely safety evaluation than crash-based analysis. Four pedestrian safety treatments were evaluated through the conduct of before-after studies. These treatments included adding a leading protected left-turn phase, implementing split phasing, implementing pedestrian recalls, and increasing the Walk interval duration. The first three treatments were found to reduce pedestrian-vehicle conflict rates. The treatments had mixed effects on pedestrian compliance.