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Publication Number:  FHWA-HRT-18-059    Date:  October 2018
Publication Number: FHWA-HRT-18-059
Date: October 2018


Safety Evaluation of Protected Left-Turn Phasing on Pedestrian Safety

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FHWA Publication No.: FHWA-HRT-18-059
FHWA Contact: Ann Do, HRDS-30, (202) 493-3319, ann.do@dot.gov

This document is a technical summary of the Federal Highway Administration report Safety Evaluation of Protected Left-Turn Phasing and Leading Pedestrian Intervals on Pedestrian Safety (FHWA-HRT-18-044).

Introduction and Objective

Pedestrian safety is an important issue for the United States, with pedestrian fatalities representing approximately 16 percent of all traffic-related fatalities in 2016.(1) In recognition of the magnitude of this problem, the Federal Highway Administration (FHWA) funded a study to evaluate promising infrastructure improvements to increase pedestrian safety. Following a literature review that summarized the existing knowledge on 18 countermeasures, FHWA and a Technical Advisory Panel selected 2 as the highest priorities for detailed evaluation in this study—the provision of protected and protected/permissive left-turn phasing and the provision of leading pedestrian intervals (LPIs). The objective of the study was to develop statistically rigorous crash modification factors (CMFs) for these countermeasures using state-of-the-art analytical methods.

This TechBrief summarizes the evaluation of protected left-turn phasing. FHWA wrote a separate TechBrief for the evaluation of leading pedestrian intervals.(2) The safety effectiveness of the countermeasure was measured by crash frequency of vehicle–pedestrian crashes (all severities combined), vehicle–vehicle crashes (all severities combined), and vehicle–vehicle injury crashes (K, A, B, and C severities on the KABCO scale, where K is fatal injury, A is incapacitating injury, B is nonincapacitating injury, C is possible injury, and O is property damage only). The analysis was conducted using an empirical Bayesian (EB) before–after study design and data from urban intersections in three cities that had installed the countermeasure of interest (Chicago, IL; New York City (NYC), NY; and Toronto, ON).

FHWA-HRT-18-059 PDF Cover Image



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