Safety Impact of Automated Speed Camera Enforcement: Empirical Findings Based on Chicago’s Speed Cameras

Abstract

Speeding was a factor in over a quarter of crash fatalities annually in the U.S. from 2009 to 2018. In some cities, automated speed camera enforcement is being used to curb speeding and improve roadway safety in instrumented areas. This paper reviews the effectiveness of automated speed cameras and some of the considerations informing the public debate around them in the United States. It then employs data from the City of Chicago, Illinois and the empirical Bayes approach to examine how effective speed cameras have been at reducing injury crashes and fatalities. Chicago installed most of its currently operating speed cameras in the 2013 to 2014 period. From 2015 to 2017, we estimate a 12% reduction in fatal and injury crashes across treated locations included in our analysis. Fatality and severe injury crashes declined by 15%. Some treated sites did not see the expected safety benefits, however. Recommendations to improve efficacy are made.