How average speed cameras work - and how you can avoid getting a fine

There are a lot of myths about average speed cameras - here are the facts

Speed cameras are a constant topic of discussion, whether they're mobile, fixed, average speed or smart motorway cameras. We've taken a look at how average speed cameras function and how drivers can avoid being caught out for speeding.

How do these cameras work?

At least two cameras are set up at different points along a road, a minimum of 200m apart, and are synchronised to record the exact time each car passes using number plate reading technology, as reported by Bristol Post. A computer then calculates the average speed between the cameras to determine if the vehicle was exceeding the speed limit.

Some drivers mistakenly believe that each camera records their speed as they pass each one before the computer calculates the average speed as the car passed every camera - this is why some drivers think they can speed up between the cameras and slow down as they pass them. However, this approach is likely to result in a fine - the cameras simply record the time you pass them and the computer works out how long it has taken you to pass the distance between them.

Do the cameras work at night?

Yes, according to Wales Online. They are equipped with infra red illuminators to ensure they operate day and night, in all weather conditions.

Can the cameras run out of film?

No. Unlike some other speed cameras, average speed camera data is stored on a computer.

Can the cameras catch motorbikes?

Yes, the cameras are designed to capture all types of vehicles.

If a vehicle changes lanes, will they avoid any fines?

No, the cameras account for lane changes.

However, this misconception can lead people to dangerously switch lanes, increasing the likelihood of accidents.

If a driver passes more than two sets of average speed cameras in a sequence while over the speed limit, will they be fined more than once?

This is unlikely.

Only certain cameras in the sequence are typically 'paired', so where, for example, there are four in a sequence it may be your speed between the first and third that is recorded, or the second and fourth or first and fourth, and so on. But you will not know which ones are recording your number plate at any time.

Where there are separate sections of the same road where average speed camera zones are in force, however, a driver would be committing separate offences by speeding through each one.

If you are less than 10 per cent above the limit, will you get a ticket?

It has been commonly assumed by many drivers over the years that you will not get a ticket as long as your speed does not exceed the limit by more than 10 per cent plus 2mph.

This is due to guidance to officers from the National Police Chiefs Council. Several police forces nationwide have indicated that drivers can expect far less leeway, as cameras become more accurate - and the law states that a driver can receive a ticket as soon as they have exceeded the limit, even if it is only by 1mph.

How can you steer clear of a fine?

There's only one foolproof method to avoid receiving a ticket from average speed cameras - and that's by adhering to the speed limit.