Where to Implement Leading Pedestrian Intervals: An Examination of Turning Vehicle-Pedestrian Crashes at Signalized Intersections

Pedestrian safety is a critical transportation and public health issue, with fatalities increasing substantially over the past decade. Given this trend, it is important to understand where and when to most effectively implement countermeasures that help prevent pedestrian crashes, injuries, and fatalities. The leading pedestrian interval (LPI) is one such countermeasure which is considered relatively low-cost and has been shown to improve pedestrian safety. The LPI gives pedestrians a WALK indication 3-7 s before parallel vehicles receive a green indication at signalized intersections, potentially reducing the probability of turning vehicle-pedestrian crashes. LPI implementation may depend on many factors, and several implementation guidelines exist; however, these guidelines can vary from jurisdiction to jurisdiction, and weighting schemes may not always be based on empirical data. To address this issue, this study utilized roadway, traffic, and built environment data from 1,067 signalized intersections in Phoenix, Arizona, along with 2016-2022 crash data in developing a negative binomial regression model to analyze factors associated with turning vehicle-pedestrian crashes. Model results were compared with existing guidelines, and several variables commonly considered for LPI implementation were found to be significant predictors of turning vehicle-pedestrian crash frequency including activity density, major and minor road volumes, transit stop presence, proximity to schools, and number of intersection legs, among others, all at differing magnitudes. Ultimately, the relative predicted impacts of these characteristics may be useful to practitioners, researchers, and policymakers by providing data-driven evidence to help establish weighting schemes and other considerations for future iterations of LPI implementation guidelines.