Quantitative Measurement Procedures for Pedestrian Service at Signalized Intersections: Case Study at Skewed Intersection

The pedestrian level of service for signalized intersections in the Highway Capacity Manual is based on pedestrian delay. While delay is an important parameter, it does not consider other factors such as likelihood of a pedestrian successfully and safely completing a crossing maneuver within the allotted time. This paper proposes a methodology for measuring pedestrian service based on three discrete pedestrian crossing outcomes: non-conflicting, compromised, and failed. These pedestrian outcomes provide a quantitative means for assessing the pedestrian service at a signalized intersection. A case study of four crosswalks at a single intersection is presented to demonstrate how these definitions can be used to evaluate the pedestrian service at a signalized intersection. The results of the case study indicate that one of the four pedestrian crossings exhibits a significantly higher rate of compromised and failed pedestrian crossings. This quantitative finding is corroborated by the presence of geometric characteristics, conflicting vehicle volumes and pedestrian signal phasing characteristics that are all qualitatively associated with increasing the difficulty a pedestrian encounters crossing the road. Additional research focused on modeling the relationship between these characteristics is suggested that ultimately may allow estimation of pedestrian crossing outcomes based on intersection geometry, volumes, and signal timing. Such a model is highly desirable as it would provide engineers with tools to quantitatively predict locations where existing pedestrian service may not adequately serve pedestrian needs without waiting for pedestrian-vehicle accidents to identify locations where pedestrians are at risk.