The Effects of Suspending Enforcement

• In Event: Assessing the Effectiveness of Deterrence-Based Policies

Abstract

The study exploits a unique situation in Israel, where following a legal question 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. Using official data on fatal and severe crashes over a period of three years and a quasi-experimental design, we compared the number of casualties in crashes that occurred near a camera (up to 1 km) and those occurring far from the nearest camera (5 km or more) before and after the suspension of enforcement through stationary automatic cameras. Findings from a multivariate negative binomial regression indicate that before the suspension there were significantly fewer casualties in crashes near stationary speed cameras compared to crashes occurring far away from a camera, by about 22%. However, after the suspension this difference vanished. 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.

Authors

• Ron Factor, The Hebrew University, Israel

• Noam Haviv, The Ashkelon Academic College

• Guy Keren, The Hebrew University of Jerusalem, Israel