The Impact Of Red Light Cameras Automated Enforcement On Safety In Arizona

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.

At head of title: National Cooperative Highway Research Program.

Contains summaries of the knowledge regarding the effects of 128 road safety measures. This title covers various areas of road safety including: traffic control; vehicle inspection; driver training; publicity campaigns; police enforcement; and, general policy instruments. It also covers topics such as post-accident care, and speed cameras.

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.