Co-Investigators
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Nichole Morris, Director, Human Factors Safety Lab, Mechanical Engineering
Summary
Agencies may treat pedestrian crossing sites initially with temporary treatments (i.e., removable flexible delineators or bollards) to test efficacy, but the pedestrian safety effects of temporary infrastructure are not well understood. This study tested the impact of temporary and permanent pedestrian infrastructure such as curb extensions/bump-outs and pedestrian medians/refuges as it relates to pedestrian and driver behavior. Twelve intersections in Minneapolis and Saint Paul, MN, comprising a mixture of intersection traffic control types and pedestrian infrastructure were examined before and after installation of the infrastructure. Staged pedestrian crossings by research staff at crosswalks examined driver stopping behavior and analyzed video data from installed traffic cameras to examine natural pedestrian behavior. A computer algorithm processed the video data to estimate vehicle speeds at the sites. For signalized intersections, the use of flexible delineators as a curb extension led to a reduced likelihood of drivers stopping for pedestrians during staged crossings. Little to no effect was found for permanent curb extensions at signalized intersections, perhaps due to the role that increased physical separation and visual complexity plays in the likelihood of drivers stopping for pedestrians. For unsignalized intersections, both temporary and permanent curb extensions were found to have similar and mixed effects for pedestrian safety when considering average driver speed, stopping likelihood, and pedestrian behavior. Both permanent and temporary medians had generally positive effects for the pedestrian safety measures, especially for average driver speed. Future research should closely examine the relative pedestrian safety impacts of temporary and permanent refuges at signalized intersections.