Impact Of Red Light Camera Enforcement On Crash Experience

At head of title: National Cooperative Highway Research Program.

Red Light Cameras (RLCs) have been used in a number of U.S. cities to yield a demonstrable reduction in red light violations; however, evaluating their impact on safety (crashes) has been relatively more difficult. Accurately estimating the safety impacts of RLCs is challenging for several reasons. First, many safety related factors are uncontrolled and/or confounded during the periods of observation. Second, "spillover" effects caused by drivers reacting to non-RLC-equipped intersections and approaches can make the selection of comparison sites difficult. Third, sites selected for RLC installation may not be randomly selected, and as a result may suffer from the regression to the mean effect. Finally, crash severity needs to be considered to fully understand the safety impacts of RLCs. With these challenges in mind this study was designed to estimate the safety impacts of RLCs on traffic crashes at signalized intersections in the state of Arizona and to identify which factors are associated with successful installations. RLC equipped intersections in the cities of Phoenix and Scottsdale are examined in detail to draw conclusions as to the relative success of RLC programs in these two jurisdictions. Both jurisdictions are operating successful installations of RLCs. Factors related to RLC effectiveness appear to include crash type and severity, left-turn phasing, presence of warning signs, approach speeds, and signal timing. Recommendations are made as to under what conditions should RLCs be considered.

Red light running, which is defined as the act of a motorist entering an intersection after the traffic signal has turned red, caused almost 5,000 crashes in Virginia in 2003, resulting in at least 18 deaths and more than 3,800 injuries. In response to a June 2, 2004, directive from Virginia Secretary of Transportation Whittington W. Clement, an evaluation of the photo-red enforcement programs that operate in Virginia was undertaken. Generally, Virginia's photo-red programs are technically feasible. Case law strongly indicates that the programs pass legal muster in the three key areas: privacy, equal protection, and due process, and public opinion surveys suggest that roughly two-thirds of respondents support red light cameras. There is, however, a practical issue with regard to issuing citations for out-of-state motorists, as noted in the report. Although an economic analysis was not feasible in the study time frame, a limited fiscal analysis suggests that, in general, Virginia localities are not generating net revenue. Finally, an operational analysis based on violations and crashes shows a potential but not definite safety improvement. The cameras clearly affect driver behavior; across the 23 intersections where reliable citation data could be obtained, citations decreased by an average of 21% per intersection. Further the data show that the cameras are correlated with a definite decrease in crashes that are directly attributable to red light running, a definite increase in rear-end crashes, a possible decrease in angle crashes, a net decrease in injury crashes attributable to red light running, and an increase in total injury crashes. More time is needed to determine whether the severity of the eliminated red light running crashes was greater than that of the induced rear-end crashes. The report recommends that Virginia's photo-red enforcement programs be continued for an additional year to resolve this question and to collect additional data that was not feasible during the 6-month time frame of this report.

The goal of this research was to find out which automated enforcement programs have been successful and what contributed to their success, as well as which programs have been unsuccessful and to draw lessons from their experiences. This was accomplished through a comprehensive assessment of automated speed and red light running enforcement activity in the United States and Canada, which led to the development of guidelines to assist agencies in implementing and operating successful automated enforcement programs. Over 350 jurisdictions with current or past automated enforcement programs were contacted by survey and phone as part of the assessment. In addition to the survey, an extensive literature review was conducted to determine the effect of the programs, cost effectiveness, and resource requirements, and to get the perspective of the public.