The cameras are being progressively introduced at intersections with a history of serious crashes, which is the sole criterion for selecting red light camera locations. Recent red light camera trials in Canberra found there was also a high incidence of speeding through traffic lights, while some vehicles were detected both speeding and running red lights at the same time. Crashes at intersections generally involve a side impact collision with a consequent high risk of serious injury or death. The higher the speed, the greater the risk. Speed cameras have also proved to be an effective deterrent to speeding.
Sensors embedded in the road detect the presence of vehicles at the intersection.
If a vehicle proceeds against a red light, a signal is sent to the camera, which then takes a series of colour photographs of its passage through the intersection, as well as a close-up of the number plate. The same sensors also calculate the speed of vehicles at the intersection and activate the camera if the pre-set limit is exceeded. This occurs regardless of whether the traffic lights are green, red or amber. The system is able to detect red light and speeding offences that occur simultaneously. Vehicles that are speeding and running red lights at the same time can incur infringement notices for both offences.