free hit counter

How They Work

Get Adobe Flash player

Fixed Truvelo speed camera
Fixed Truvelo speed camera

Truvelo cameras are similar to Gatso cameras, in that they are permanently installed next to the carriageway. However, unlike Gatso cameras, the can be rotated to take photographs of either the front or the rear of a vehicle. A magenta filter is applied to the flash to prevent oncoming drivers from being dazzled. Truvelo camera housings are painted yellow to make them visible to motorists from a distance.

In front facing mode, Truvelo cameras work as follows:

  • Sensors in the road record the time at which the vehicle crosses them.
  • The time difference between sensors 1 and 3, and between sensors 2 and 4, is calculated. These measurements are used to calculate the speed of the vehicle.
  • If the vehicle's speed is above a preset threshold (eg. 30 mph) then a photo is taken.
  • There are three white lines painted on the road surface. The photo is taken when the vehicle crosses the middle white line. The other two white lines are set at +/-10%. This is the legal required accuracy.

In rear facing mode, Truvelo cameras work as follows:

  • Sensors in the road record the time at which the vehicle crosses them.
  • The time difference between sensors 1 and 3, and between sensors 2 and 4, is calculated. These measurements are used to calculate the speed of the vehicle.
  • If the vehicle's speed is above a preset threshold (eg. 30 mph) then two photographs are taken.
  • These photographs show the vehicle's position in relation to the check marks on the road.

Truvelo cameras are less common than Gatso cameras in the West Midlands, but are used in locations where front facing cameras are more suitable. Though the technology is different, the cameras are still used based on a deployment strategy.

More information

These diagrams and explanations are designed to give a fair interpretation and overview of how different cameras work. They are not an exact technical representation of cameras and camera sites.

Birmingham City Council Coventry City Council Dudley Council Her Majestys Courts Service Highways Agency Sandwell council Solihull Council Walsall Council West Midlands Police Wolverhampton City Council