All fixed speed control safety cameras are designed to measure the speed of approaching vehicles, or departing vehicles, or both, depending upon the type of camera.
They are calibrated so that vehicles travelling within the speed limit are invisible. Only vehicles travelling above the limit are seen and photographed by the camera.
Gatso cameras are activated as the vehicle crosses a radar beam and takes two photographs half a second apart, whilst Truvelo cameras are activated as the vehicle travels over sensors in the roads. On-board computers instantly calculate the distance travelled between the two points.
It's basic maths - distance travelled over time = speed.
The white line markings on the road surface provide a secondary back-up check, verified by an operative who examines the film taken by the camera.
Every camera is checked to ensure it is properly calibrated and working every single time it is placed inside its yellow housing. Twenty-four hours or so later, when the camera and film are removed, the camera is checked again to ensure that it has been working properly. In addition, the camera conducts a self-test every time it takes a photograph. Furthermore, every single photograph is subsequently checked 'by eye' by an operative.
The calibration and checking regime is rigorous in the extreme to ensure that no innocent motorists are accidentally caught by the cameras. In other words, the cameras are only capable of catching speeding motorists. So, if they catch you, you have been speeding
The mobile safety camera units operate across the region using a range of different equipment. The Partnership uses mobile Gatso cameras, which are bright orange in colour and are mounted on a tripod on the side of the road. The Partnership also uses highly sophisticated and accurate laser technology which is housed in the mobile vans or from a specially adapted motorbike.
The cameras operate effectively in poor light conditions, including night-time and also in rain and snow without the beam being refracted by water drops. This ability will enable the roadside patrols to be available to assist motorists more often and for longer during winter months when road conditions are generally more hazardous, road surfaces are often slippery and driving at a safe and appropriate speed becomes even more important.
The equipment is calibrated daily, before and after each time it's switched on, and it self-tests every time it takes a picture. In-built anti-tampering security measures prevent camera settings being altered by the officers (or anyone else).
Red Traffic Light Cameras
Red traffic light safety cameras monitor the junction at which they are located twenty-four hours a day. Vehicles that cross the Stop line break a magnetic field that causes a photograph to be taken of the offence. It does not record the vehicle speed but does record the make, model and registration details which can be used to trace the owner and issue a Fixed Penalty Notice. These cameras are also activated by vehicles that exceed the speed limit whilst the light is on green.
Safer Road Humber are operating speed and red traffic light cameras at Lindsey Oil Refinery, Immingham, to protect workers and contractors during a major refit of the plant.