Safety Evaluation of Red-Light Indicator Lights (RLILs) (Full and TECHBRIEF)
This study evaluated red-light indicator lights (RLILs). RLILs are auxiliary lights mounted on signal heads, mast arms, or poles that were connected to a traffic-control signal. This strategy is to reduce the frequency of crashes resulting from drivers disobeying traffic signals by providing a safer means for police to enforce the red interval. The RLIL activates at the onset of the red phase and allows an enforcement officer to observe red-light running from downstream of the intersection. Results indicate statistically significant crash reductions for most crash types (i.e., total crashes, fatal and injury crashes, right-angle, and left-turn). The B/C ratio estimated with conservative cost and service life assumptions indicates this strategy was highly beneficial for four-legged signalized intersections. This report will benefit traffic engineers, enforcement personnel, and safety planners by providing insight for greater intersection safety.