Do mobile cameras lie?

A BBC programme has revealed major concerns about the accuracy of mobile speed cameras, with a brick wall creating a recorded speed of 58mph.

The machines rely on the infra red beam they sent being reflected back to the source, ideally being targeted at the number plate of vehicles to ensure the beam is bounced straight back to the machine.

Hitting a wing mirror, or targetting different parts of a vehicle can lead to errors. The BBC showed that by panning a camera along a stationary vehicle it can be clocked at 4mph, while panning along a stationary brick wall recorded a speed of 58mph.

The camera used to test these theories was the LTI 20.20, imported by Tele-Traffic, and the firm rejects any possibility of errors. The system should display an error message if there is any targetting slippage, and the camera could display speeds out by no more than 1 or 2mph.

A video was shown to the firm in which a camera recorded speeds indicating the vehicle was travelling in the opposite direction to the way it is seen going on screen, but Tele-Traffic attribute this to user error rather than camera error.

Read more about the mobile camera concerns, here.