Enforcement and behavior: the effects of suspending enforcement through automatic speed cameras

Objectives: The study exploits a unique situation in Israel where the distribution of traffic tickets using automatic speed enforcement cameras was suspended, while the system remained physically intact. This situation provides an opportunity to test the effects of non-enforcement on drivers’ behavior. Methods: Using 3 years of data on fatal and severe crashes and a quasi-experimental design, we compared the number of casualties in crashes occurring near (< 1 km) and far (> 5 km) from the nearest camera before and after the suspension of automated enforcement. Results: A multivariate negative binomial regression indicates that before the suspension there were significantly fewer casualties (by 22%) in crashes near cameras compared to crashes farther away. After the suspension of automated enforcement, this difference vanished. Conclusions: The findings provide evidence for the effectiveness of stationary speed cameras in reducing casualties and show how human behavior changes in light of deterrence and enforcement.