THERE are two main types of speed camera you will see on the roads in Bolton.

Fixed speed cameras are the most common ones on our roads. They are rear-facing cameras which to catch motorists exceeding the speed limit on a given road.

The first speed camera in the UK was put up in the A316 over Twickenham bridge in 1992.

The speed limit was 40mph and the trigger speed was set at 60mph. In 22 days it caught nearly 23,000 drivers speeding at over 65mph.

Average speed cameras, like the ones in the A675/Belmont Road and the A666/St Peter's Way work differently.

They are front-facing and use number place recognition technology to detect and calculate their average speed by measuring the time taken to travel between fixed points of a known distance apart.

There is no way of knowing what speed will trigger a speed camera but you can be fined for doing even 1mph over the limit on a given road.

The Royal Society for the Prevention of Accidents estimates speed is a factor in 26 per cent of road deaths.