Analysis of infringement data from fixed red light and speed cameras at signalised intersections in South Australia

Safety cameras are installed at some signalised intersections in South Australia. They photograph vehicles that enter the intersection after the signal has changed to red, or that exceed the speed limit by more than a selected amount. Infringement data at 21 safety camera sites in metropolitan Adelaide was used to track how disobey red light and speeding infringements changed during the first year of operation. It was found that both speeding and red light running decreased over time after the installation of a safety camera. Red light running decreased slowly over time, while speeding fell more rapidly. For the more serious levels of speeding, there was a more rapid fall in infringements during the first few weeks and a slower decline thereafter. Based on this, safety cameras appear to generate a worthwhile improvement in driver behaviour. The fact that continued reductions are seen during the first year of operation suggests that some learning on the part of drivers is occurring.Mackenzie JRR, Kloeden CN, Hutchinson T