How do average speed cameras work?
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Average speed cameras are a common form of speed limit enforcement that's increasingly being used on fast-moving roads and motorways.
These cameras operate differently from standard digital Gatso speed cameras and so some drivers might be unfamiliar with how they work.
How do average speed cameras calculate your speed?
Simply put, average speed cameras calculate your speed by recording how long it takes you to travel between two set points on the road.
A minimum of two cameras placed at least 200 metres apart are required for the calculation to be made. The first camera records your number plate as you pass and your average speed is calculated once you pass the second camera.
The cameras use the formula: speed = distance/time. If you’re travelling down a motorway at the UK national speed limit of 70mph and pass through an average speed camera that’s spaced 200 metres apart, it’ll take you no less than 6 seconds to travel between the two points.
Where do you find average speed cameras?
In theory, average speed cameras can be found on pretty much any road, although you’re most likely to see them on motorways and dual carriageways.
Sometimes temporary average speed cameras are set up when there are roadworks in place and the speed limit has been lowered. In these cases, there will be signs clearly stating that they are in operation.
Average speed cameras are sometimes given the nickname ‘yellow vultures’ because they usually sit upon tall yellow poles placed to the side of the road. The cameras look similar to CCTV cameras.
What happens if an average speed camera catches you speeding?
If you do exceed the speed limit you won’t receive any visual indication like a camera flash. This is because infrared lights are used to reliably read number plates in low light conditions.
The penalty for an average speed camera is the same as with any other camera. A £100 fine and 3 points on your licence is the minimum that you’ll receive, although you may be offered a speed awareness course instead.
Depending on how far over the speed limit you’re travelling you can receive up to 6 points on your licence or even disqualification with fines up to £1,000.
Read more about speed cameras here.