Institute of Transport Studies , Department of Civil Engineering , Building 60, Monash University , Clayton , Victoria 3800 , AUSTRALIA Phone: +61 3 9905 51851 , Fax: +61 3 9905 4944 , Email: farhana.naznin@monash.edu.
OBJECTIVE: Streetcars/tram systems are growing worldwide and many are given priority to increase speed and reliability performance in mixed traffic conditions. Research related to the road safety impact of tram priority is limited. This study explores the road safety impacts of tram priority measures including lane and intersection/signal priority measures.
METHOD: A before-after crash study was conducted using the Empirical Bayes (EB) method to provide more accurate crash impact estimates by accounting for wider crash trends and the regression-to-the-mean effects. Before-after crash data for 29 intersections with tram signal priority and 23 arterials with tram lane priority in Melbourne, Australia were analyzed to evaluate the road safety impact of tram priority.
RESULTS: The EB before-after analysis results indicated a statistically significant adjusted crash reduction rate of 16.4% after implementation of tram priority measures. Signal priority measures were found to reduce crashes by 13.9% and lane priority by 19.4%. A disaggregate level simple before-after analysis indicated reductions in total and serious crashes as well as vehicle, pedestrian and motor cycle involved crashes. Also reductions in on-path crashes, pedestrian-involved crashes and collisions among vehicles moving in the same and opposite directions, and all other specific crash types were found after tram priority implementation.
CONCLUSIONS: Results suggest that streetcar/tram priority measures result in safety benefits for all road users, including vehicles, pedestrians and cyclists. Policy implications and areas for future research are discussed.