Impacts of Red Light Camera on Violation Characteristics

This paper presents the findings of a before-and-after study which evaluated the impacts of installing and operating red light cameras (RLC) at two “T” and one “X” signalized intersections. The red running violations and vehicle entry times were gathered before and shortly after RLC installation along each individual approach. After RLC installation, red running violations were substantially reduced by more than 40% at camera approaches but not the case for the opposing noncamera approaches. Overall, there was still an aggregated net reduction of about 7% across all approaches. The RLC was found to be more effective in curbing violations during weekends at camera approaches as well as encouraging red-running violators to speed up and clear the camera approaches more speedily. This had generally resulted in lower entry times of red running vehicles. From the results obtained using generalized linear modeling, it was found that the presence or absence of RLC significantly influenced the after-red times, and lower mean after-red times were observed for camera approaches. In effect, the higher the mean after-red time the higher the rate of red running violations.