Performance of safety cameras in London: Final Report

Safety cameras are a familiar sight throughout the country, and have been used in London for just over a decade. This report details a robust analysis of the safety performance of the speed cameras under the authority of the London Safety Camera Partnership, focusing on those which would have met the current primary government criterion for installation (i.e. having four or more collisions, each involving at least one person who was killed or seriously injured, in 3 years, over a distance of 1 km). Red-light cameras were not included in the analysis. The principal methodology adopted for this research was a "before" and "after" study comparing collision numbers at safety camera sites with those at suitably matched control sites. The study design enabled the effects of cameras to be isolated from regression-to-mean and trend effects. A secondary methodology, known as Empirical Bayes, was also used which enabled estimates of the effects of cameras on individual types of accident to be made.