Citation

Llau AF, Ahmed NU, Pekovic V, Khan HM, Cevallos FG. Traffic Injury Prev. 2015; 16(8): 773-780.

Affiliation

a Epidemiology , Robert Stempel School of Public Health, Florida International University , Miami , Fla , U.S.

Copyright

(Copyright © 2015, Informa - Taylor and Francis Group)

DOI

10.1080/15389588.2015.1023896

PMID

25793316

Abstract

OBJECTIVE To determine the safety effect of red light camera (RLC) programs, this study attempted to estimate its impact on collisions within Miami-Dade County, Florida Methods A before-after evaluation using a comparison group along with traffic control correction was employed. Twenty signalized intersections with RLCs which began enforcement on January 1(st), 2011 were matched to two comparison sites located at least two miles from camera sites to minimize spillover effect. An Empirical Bayes analysis was used to account for potential regression to the mean effects. An index of effectiveness along with 95% CI's were calculated based on the comparison between the estimated and actual number of crashes in the after period.

RESULTS During the first year, RLC sites experienced a marginal decrease in right-angle/turn collisions (-3%), a significant increase in rear-end collisions (+40%), and significant decreases in all-injury (-19%) and RLR-related injury collisions (-24%). An increase in right-angle/turning (+14%) and rear-end (+51%) collisions at the RLC sites was observed after two years despite camera enforcement. A significant reduction in RLR-related injury crashes (-17%), however, was still observed after two years. A non-significant decline in all injury collisions (-12%) was also noted.

CONCLUSIONS RLCs showed a benefit in reducing RLR-related injury collisions at camera sites after enforcement commenced, yet its tradeoff was a large increase in rear-end collisions. There was inconclusive evidence whether RLC's affected right-angle/turning and all injury collisions. Statutory changes in crash reporting during the second year of camera enforcement affected the incidence of right-angle and rear-end collisions, nevertheless, a "novelty effect" could also not be ruled out. Future research should consider events such as low frequencies of severe injury/fatal collisions and changes in crash reporting requirements when conducting RLC analyses.

Language: en