DANIEL B. FAMBRO STUDENT PAPER AWARD WINNER Impacts of Red-Light Cameras on Intersection Safety: A Bayesian Hierarchical Spatial Model Shutterstock/monticello By Soheil Sohrabi (S) and Dominique Lord, P.Eng., Ph.D. (M) (Advisor) I ntersection safety is one of the most significant issues cities face in managing traffic safety. It has been shown that red light running (RLR) is an important contributing factor for crashes at signalized intersections.1 According to the Insurance Institute of Highway Safety (IIHS), red-light runners encompass about 800 deaths and 137,000 injuries annually in the United States.2 Introducing enforcement as an effective way to change driver behavior at intersections and consequently to prevent RLR has incentivized cities to implement automated red light camera (RLC) programs. In a recent study, the safety at intersections with RLC systems in 57 cities was compared to that of 33 cities without such a program.3 The comparison showed that the ratio of RLR fatal crashes per capita to all intersection-related fatal crashes improved by 21 percent after the RLC program implementation. w w w .i t e.or g D e cember 2019 29http://www.ite.org