Is a combined enforcement and penalty strategy effective in combating red light violations? An aggregate model of violation behavior in Hong Kong.

Red light violations are a major cause of traffic crashes at signalized intersections. In Hong Kong, prosecutions for red light violations have increased in the past decade. An automated enforcement camera system has been established to combat this prohibited driver behavior. In addition, both demerit points and financial penalties were revised upwards in 2006 to strengthen the deterrent effect of the system. An observational study of driver tendency to run a red light was conducted to evaluate the effectiveness of the combined penalty and camera strategy. Both the short- and long-term effects of the strategy on red light violations were estimated. The influences of factors including temporal variation, the presence of a red light camera, geometric design, and traffic control type were also determined with an aggregate count data model. The results show that the frequency of red light violations significantly decreased after the implementation of the new penalty system, and that the reduction remained significant one year after implementation. Interestingly, no evidence was found for an association between the frequency of red light violations and the presence of a red light camera.