Study Details
Study Title: Effectiveness and Site Selection Criteria for Red Light Camera Systems
Authors: Ko et al.
Publication Date:JAN, 2013
Abstract: The objective of this paper is to evaluate the safety effectiveness of automated traffic enforcement systems, that is, red light cameras, installed at 254 signalized intersections in 32 jurisdictions in Texas. In addition, criteria for site selection were evaluated to provide analytical resources for camera installation. A before–after study by the empirical Bayesian methodology was performed to remove the regression-to-mean bias during the evaluation of treatments. The results indicate significant decreases in the incidences of all types of red light running (RLR) crashes and right-angle RLR crashes by 20% and 24%, respectively. A significant increase of 37% for rear-end RLR crashes was discovered. The study results suggest that a significant safety benefit for red light cameras is achieved if intersections have four or more RLR crashes per year or have two or more RLR crashes per 10,000 vehicles. Red light cameras show counterproductive results if intersections experience fewer than two RLR crashes per year or have one crash per 10,000 vehicles per year. This paper also evaluated criteria for the selection of sites for the implementation of RLC systems. Intersections are selected for the treatment on the basis of crash history, traffic volume, or crash rate. However, no specific guidelines on when the implementation of RLC systems is warranted exist. The results of this study demonstrate that RLC systems have a significant and positive impact when intersections with greater than or equal to four crashes per year or a crash rate of two crashes per 10,000 vehicles per year are selected for the treatment. It is expected that those intersections will have a reduction of about two or more RLR crashes per year after the RLC installation. If the intersections with less than two RLR crashes per year or a crash rate of less than one are selected, then a negative safety impact should be expected after the treatment.
Study Citation: Ko, M., S. R. Geedipally, and T.D. Walden. "Effectiveness and Site Selection Criteria for Red Light Camera Systems". Transportation Research Record No. 2327, Transportation Research Board of the National Academies of Science, Washington, D.C., (2013).
Related Citations: Walden, T. and Bochner, B., "Effectiveness of Red Light Cameras-Texas Statewide Evaluation." ITE Journal, Vol. 81, No. 12, (2011) pp. 30-33.
CMFs Associated With This Study
Category: Advanced technology and ITS
Countermeasure: Install red-light cameras
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|---|---|---|---|---|---|
| 0.8 | 20 |  | All | All | Not specified |
| 0.76 | 24 | | Angle | All | Not specified |
| 1.37 | -37 |  | Rear end | All | Not specified |
