Effects of Red Light Cameras on Violations and Crashes: A Review of the International Literature

Abstract

Red light running is a frequent cause of motor vehicle crashes and injuries. A primary countermeasure for red light running crashes is police traffic enforcement. In recent years, many police agencies have begun using automated red light cameras as a supplement to conventional enforcement methods. The present study reviewed and evaluated available evidence in the international literature regarding the effectiveness of cameras to reduce both red light violations and crashes. Camera enforcement generally reduces violations by an estimated 40-50%. In terms of crash effects, most studies contain methodological flaws that, to varying degrees, either overestimate (failure to adjust for regression to the mean) or underestimate (comparison with nearby signalized intersections affected by cameras) crash effects. Mindful of these limitations, the research generally indicates that camera enforcement can significantly reduce injury crashes at signalized intersections, in particular right-angle injury crashes. Most studies reported increases in rear-end crashes following camera installation. Taken together the studies indicate that, overall, injury crashes, including rear-end collisions, were reduced by 25-30% as a result of camera enforcement.

Impact of Signal Timing Information on Safety and Efficiency of Signalized Intersections

“…Retting et al (2003) reviewed and evaluated the international literature regarding the effectiveness of cameras to reduce both red light violations and crashes and reported that, overall, injury crashes including rear-end collisions,…”

Helmets Matter: Kentucky Motorcycle Crash Victims Seen at a Tennessee Trauma Center

“…Effectiveness: Red-light camera effectiveness has been studied fairly extensively. Summary reviews conclude that they increase rear-end crashes, reduce side-impact crashes (the target group), and reduce overall crash severity (Aeron- Thomas & Hess, 2006;Decina, Thomas, Srinivasan, & Staplin, 2007;Maccubbin et al, 2001;McGee & Eccles, 2003;Retting, Ferguson, & Hakkert, 2003;WHO, 2004). Because there tend to be increases in lower-severity rear end crashes that somewhat offset reductions in the target group of higher-severity angle crashes, cameras were found to be more beneficial at intersections with a higher ratio of angle crashes to rear-end crashes.…”

Countermeasures that work: A highway safety countermeasure guide for state highway safety offices

“…Effectiveness: Red-light camera effectiveness has been studied fairly extensively. Summary reviews conclude that they increase rear-end crashes, reduce side-impact crashes, and reduce overall injury crashes perhaps by as much as 25 percent (Aeron- Thomas and Hess, 2005;FHWA, 2005b;IIHS, 2002;Maccubbin, 2001;Retting et al, 2003;WHO, 2004, p. 132). Speed cameras also reduce crashes substantially, though no studies have been conducted in the United States (IIHS, 2005e;WHO, 2004, p. 128).…”