Fixed safety camera systems assess the speed of every vehicle passing through a speed detection zone, the cameras will only operate/trigger if the assessed vehicle is travelling at or above the threshold of speed set within the camera system.

The offence images produced by the camera show the time and date of the offence and are displayed along with a photograph(s) of the offending vehicle.

The registration plate of the offending vehicle is used to identify the registered keeper who will then be sent a notice of intended prosecution.

The Gatso

This type of camera is a radar operated system. Every vehicle entering the radar zone is assessed, the information produced by the radar is processed by the built in computer and if the speed of the vehicle is at or above the speed threshold, the computer triggers the camera.

The camera takes two images 0.7 seconds apart which are then used to verify the offence.

The white lines painted on the road which are near the speed detection zone provide a secondary check and are used to confirm the speed of the vehicle depicted by the camera system.

The Truvelo

This system detects the speed of passing vehicles by using sub surface sensors which are embedded in the road. When pressure from the front wheels of a vehicle is applied to the sensors they begin a distance divided by time calculation. The sensors produce two independent speed readouts per vehicle and the lower of the two speeds is used as the primary speed readout, for the camera to trigger and for there to be a valid offence the lower speed detected by the camera must be at or above the speed threshold set within the camera system.

The system will then calculate where the front wheels of the vehicle will be at a set distance further down the carriageway. At this set point there will be three white lines painted on the road surface. The camera will trigger when the front wheels of the car are within these three white lines. This system takes one photo per offence.

TSS, rear facing

This system detects the speed of passing vehicles by using sub surface sensors which are embedded in the road. When pressure from the front wheels of a vehicle is applied to the sensors they begin a distance divided by time calculation. The sensors produce three independent speed readouts per vehicle and the lower of the three speeds is used as the primary speed readout, for the camera to trigger and for there to be a valid offence the lower speed detected by the camera must be at or above the speed threshold set within the camera system.

For verification of offence the camera takes two images 0.5 seconds apart, these photographs show continuous movement down the carriageway which is confirmed by the secondary check ladder markings painted on the road surface.

TSS forward facing

This system detects the speed of passing vehicles by using sub surface sensors which are embedded in the road. When pressure from the front wheels of a vehicle is applied to the sensors they begin a distance divided by time calculation. The sensors produce three independent speed readouts per vehicle and the lower of the three speeds is used as the primary speed readout, for the camera to trigger and for there to be a valid offence the lower speed detected by the camera must be at or above the speed threshold set within the camera system. The system will then calculate where the front wheels of the vehicle will be at a set distance further down the carriageway. At this set point there will be three white lines painted on the road surface. The camera will trigger when the front wheels of the car are within these three white lines. This system takes one photo per offence.

Average speed cameras

This system will read the registration plates of vehicles as they enter and exit a speed detection zone. The average speed of the vehicle is calculated by using timings taken from the registration plate, these timings are then worked into the formula speed = distance/time. The camera system uses the same set distance in every calculation to ascertain the speed of each vehicle.

Redspeed

When a violation occurs, the Redspeed system takes three digital images. A zoom shot is taken showing the vehicle license plate, then a wide angle shot showing make, model and colour. Finally, after a short delay dependant on vehicle speed, a third image is taken showing that the offending vehicle is in motion at the time of offence. Along with digital images of the offence taking place, the Redspeed system will record data that is relevant to the specific location and offence. The images are encrypted and then stored, ready to be sent to the central computer.