How do average speed cameras work and are they effective?

Updated
Newport, Wales - January 2023: Average speed cameras above the M4 motorway
Average speed cameras are becoming a more common sight on roads. (PA) (Ceri Breeze)

Motoring experts have suggested that drivers should expect to see more average speed cameras on the roads in the years ahead.

Usually, a common sight through stretches of roadworks, average speed cameras were first used in 1999 and are now a more frequent sight on standard stretches of roads. In recent weeks, for example, the cameras have been set up in favour of fixed-spot installations in areas such as Solihull in the West Midlands, Caithness in Scotland, Glasgow and Bolton.

The RAC has said they “appear to be gaining in popularity”, telling Yahoo News this is because they can be effective at controlling drivers’ speeds over longer distances rather than "just catching drivers out at specific points on the road”.

Road safety spokesperson Rod Dennis said: “It’s vital drivers understand how they work and, wherever they are introduced, keep their speed in check over the whole section of road that’s being monitored – or risk an unwelcome fine.

“Previous RAC research found a majority of drivers favour their use on faster roads over traditional fixed speed cameras and mobile speed traps.”

A road sign tells drivers they are entering a section of motorway which has average speed check cameras on, so shouldn't drive at excessive speed.
Average speed cameras are usually – but not only – seen on stretches where roadworks are taking place. (PA) (WireStock, Wirestock, Inc.)

Average speed cameras measure the average speed you drive between two set points on the road and work out whether you are going over the limit.

Driving past the first camera will trigger it to record your number plate, which is then recorded again at the second point. The cameras don't capture your speed in a single flash at one point.

This stops drivers from being able to fool the cameras by simply slowing down as they pass them, forcing them not to go faster than the maximum speed limit on that particular stretch.

The cameras are painted yellow and tend to be fixed higher than other speed cameras. They are equipped with infrared illuminators, to enable them to work in all weather conditions, 24 hours a day. They use Automatic Number Plate Reading (ANPR) technology to measure your speed, rather than images and will continue to work if a driver switches lanes.

According to the RAC, average speed cameras can work over distances up to 20 kilometres and need to appear at least 200 metres apart.

The AA has broken down the three different types of average speed camera here[1]. This includes: SPECS, which uses video and ANPR tech on motorways and dual carriageways; Siemens SafeZone cameras, which are most commonly used in towns, cities and villages; and SpeedSpike, which are linked in a network of up to 1,000 cameras and can catch drivers going in both directions.

Speed Camera Warning Sign
Average speed cameras usually come with a reduced speed limit. (PA) (Tim Slater)

While some drivers may find average speed cameras a nuisance, motoring organisations and road safety charities believe they are extremely good at preventing accidents and ensuring drivers obey road laws.

A spokesman for the AA told Yahoo News UK that they “moderate driver behaviour”, preventing vehicles from braking hard at particular points – lowering the risk of crashes or congestion.

The spokesman added: “They deal with the problem of local drivers and those familiar with those roads slowing down only where they know there are fixed cameras, and then speeding up afterwards.

"Since they proved their value on the A77 in Scotland, they have been a particular tool used along dangerous main roads through rural areas, where vehicles and farm machinery may pull out of side roads or cross over.”

Research by Road Safety Analysis in 2016 found that the number of fatal and serious collisions decreased by 36% after average speed cameras were introduced. They also substantially decreased injury collisions, especially those of higher severity.

A spokeswoman for the Road Safety Foundation told Yahoo News UK that average speed cameras “are very effective at improving speed compliance”.

She added: “The reason they are so effective is that speed is a very critical factor in determining crash likelihood but even more so survivability of crashes. Reducing speeds by a little has a large impact on collision severity – speed really does mean the difference between life and death.“

References

  1. ^ here (www.theaa.com)