Characteristics of red-light-running crashes and evaluation of retro-reflective signal backplates in preventing red-light-running violations

Red light running has become a serious safety issue at signalized intersections throughout the United States and it is therefore important to identify possible countermeasures to address the situation. Accordingly, one of the objectives of this study was to identify the characteristics of red-light-running (RLR) crashes and the drivers involved in those crashes. Driver characteristics, time and day of the crash, occupancy of the vehicle and environmental factors were tested against any relationship with the RLR crashes and non-RLR crashes. The other objective was to evaluate the effectiveness of retro-reflective signal backplates in reducing red light running as a low cost countermeasure. Using crash data from Kansas, contingency table analysis was carried out to identify whether a particular factor is related to the crash type, i.e. RLR vs other intersection crashes (non-ROR). Two methods were used to evaluate the effectiveness of reflective backplates: cross-sectional analysis using an intersection with reflective backplates and an intersection without reflective backplates, and a before-and-after study using four intersections. According to the results of contingency table analysis, driver age and safety equipment usage, injury severity of the driver, crash severity, time and the day of the crash, adverse weather conditions, and surface condition were related to crash type. Variables such as gender of the driver, light condition, presence of passengers were not related to the crash type. From the cross-sectional analysis, it was seen that reflective backplates are effective in reducing red light violations in the through and left turning traffic flows. Before-and-after study utilizing paired-t-test results showed a significant reduction in red light violations in one of the two treatment sites, while the reduction was not significant in the other.