Leading Pedestrian Intervals: Treating the Decision to Implement as a Marginal Benefit–Cost Problem. Issue 1 (2017)

• Record Type: Journal Article
• Authors: Sharma, Anuj; Smaglik, Edward; Kothuri, Sirisha; Smith, Oliver; Koonce, Peter; Huang, Tingting
• Is Part Of: Transportation research record. Volume 2620:Issue 1(2017)
• Page Start: 96
• Page End: 104
• Publication Date: 2017
• Subjects: Transportation -- Periodicals; Roads; Transport -- Périodiques; Routes -- Périodiques; Routes -- Conception et construction -- Périodiques; Roads; Transportation; 388.05
• DOI: 10.3141/2620-09
• Languages: English
• ISSNs: 0361-1981

Abstract

To improve the safety of people walking at particular signalized intersections, traffic signal engineers may implement leading pedestrian intervals (LPIs) to provide pedestrians with a walk signal for a few seconds before the parallel vehicular green indication. Previous before-and-after studies and simple economic analyses have indicated that LPIs are low-cost tools that can reduce vehicle–pedestrian conflicts and crashes at some signalized intersections. Despite this evidence, municipalities have little guidance for when to implement LPIs. A marginal benefit–cost framework is developed with quantitative metrics and extends the concept of traffic conflicts and marginal safety–delay trade-offs to analyze the appropriateness of implementing an LPI at specific signalized intersections. The method provides guidance to help quantify the probability of a conflict occurring and direction on whether to implement an LPI at a given location from macroscopic-level inputs, including number of turning movements, crash data, and geometry. A case study with sample data indicated that an LPI was cost-effective for the scenario presented.