Spillover Effect and Economic Effect of Red Light Cameras

“Spillover effect” of red light cameras (RLCs) refers to the expected safety improvement at intersections other than those actually treated. Such effects may be due to jurisdiction-wide publicity of RLCs and the general public’s lack of knowledge on the exact installation locations of RLCs. Ignoring possible spillover effect could lead to an underestimation of the benefit of RLCs. Both a naïve study and an empirical Bayes study were conducted in this project for selected intersections from the Chicago area, and the results showed that a substantial spillover effect seemed to exist for the studied intersections. The installation of RLCs would lead to changes in rear-end crashes and right-angle crashes. These crashes are often associated with different severities (K/A/B/C/PDO) and different socioeconomic impacts. Assessing the benefit and cost of installing RLCs could help agencies understand the cost effectiveness of RLCs as a safety countermeasure. Crash reduction estimates at the 41 selected RLC intersections from Project ICT R27-SP32 were used, and the results showed the cost effectiveness of installing RLCs at these intersections.IDOT-R27-SP33Ope