Average speed cameras: how do they work?

Getting a speeding ticket isn’t high up on any motorists’ to-do list, and with so many cameras around it’s easy to get caught out if you aren’t paying attention.

Average speed cameras are increasingly used in both towns and on faster moving roads, as well as on sections of motorways with roadworks that have a reduced speed limit imposed.

So what is an average speed camera and how do they work? Keep reading to find out.

How do average speed cameras work?

To put it simply, an average speed camera system tracks how long it takes you to travel between two set points on a road, measured by two cameras at each point; this information is then used to calculate your average speed.

There need to be two cameras in order for this to work and they have to be at least 200 metres apart.

When you pass the first camera, it will record your number plate. You then pass the second camera and the system will time how long it took you to travel between these two points to calculate your average speed.

For example, let’s say the cameras are 200 metres apart and the speed limit is 70 miles per hour. It should take no less than six seconds to travel between these two points at an average speed of 70mph.

This means it is no use speeding along before then slowing down as you pass the camera – your average speed will still be too high. There’s no way to beat the system.

What do average speed cameras look like?

Average speed cameras are often mounted on top of long yellow poles at the side of the road. There will be one camera monitoring each lane of traffic, and they look a bit like yellow CCTV cameras.

They differ from normal speed cameras because they are much taller, and they don’t have the powerful double flash of a standard speed camera either.

Where are average speed cameras located?

Average speed cameras can be found on all types of roads and in all speed limit zones. They are most commonly seen on dual carriageways and motorways, but they’re also used in urban areas as well as on A roads.

Temporary average speed cameras can also be set up for roadworks if the speed limit has been lowered. These have to be clearly signposted with both the new speed limit, as well as the fact that an average speed camera is in use.

The presence of speed cameras is indicated by a sign displaying an old-fashioned camera, though these signs can also be placed in areas where police conduct frequent speed checks with mobile camera vans.

What is the tolerance of an average speed camera?

Technically speaking you can be prosecuted for going 1mph over the speed limit, however, it’s unlikely that you will.

You may have heard rumours about tolerances built into speed cameras. Some do allow leeway to account for inaccuracies of car speedometers. How much depends on which police force is operating it, however.

Some constabularies allow 10% +2mph. So if you’re in a 70mph zone, for example, you’re unlikely to get a ticket unless you’re going over 79mph.

Keep in mind though that this tolerance isn’t the law, so you could end up being pulled up for doing 71mph. The only way to guarantee that a ticket won’t land on your doormat is to keep to the speed limit.

What is the penalty if I’m caught speeding by an average speed camera?

The penalty for being caught by an average speed camera is the same as with any other camera. The minimum you’ll get is a £100 fine and three points on your licence. This will increase depending on how far over the limit you’re caught at.

You can get up to six points on your licence, as well as being disqualified. The maximum fine you can be given is £1,000, or £2,500 for motorway offences.

It’ll usually take no more than 14 days for your speeding ticket to come through the door. You’ll be sent a Notice of Intended Prosecution (NIP) first, which you have to fill in with the details of who was driving and send it back. You’ll then be sent a ticket with the intended punishment detailed.

Myths about average speed cameras

• Myth: changing lanes can defeat average speed cameras. Reality: changing lanes could reportedly confuse some early average speed cameras. This is no longer the case, and all average speed cameras now cover all lanes.
• Myth: average speed cameras don’t work at night. Reality: average speed cameras use infra-red sensors, so work just as well when it’s dark.
• Myth: you can only receive one penalty over for speeding over a stretch of road with average cams. Reality: average speed cameras work in pairs, detecting how long it takes to cover a certain distance; but a single zone can have multiple pairs of cameras, potentially leading to multiple speeding penalties.

Average speed cameras FAQs

Do average speed cameras flash?

Average speed cameras do not flash as other fixed speed cameras do. This is because they use infra-red light to read your number plate in low light and poor weather conditions. There is no visual indication of being caught by an average speed camera.

Do average speed cameras take pictures of the driver?

No, average speed cameras don’t take a picture of the driver. If you’re caught, you have to fill out a form identifying the driver at the time of the offence. Failure to do this is a criminal offence and the registered keeper of the car can be prosecuted.

Are average speed cameras always on?

It’s always safest to assume that average speed cameras are always on, however, if they’re not then you’ll usually see a sign saying ‘camera not in use.’

What do average speed camera signs look like?

An average speed camera sign looks like a normal speed camera sign, and it’ll say ‘average speed check’ underneath.

Do average speed cameras work in the dark?

Average speed cameras use infra-red light to read number plates in the dark and in poor weather conditions. So yes, they do work at night.

Are smart motorway cameras average speed cameras?

Smart motorways are often covered by average speed cameras. If the speed limit is temporarily lowered, the average speed cameras will be adjusted to reflect this. Smart motorways may also feature fixed speed cameras, too.

Can one average speed camera catch you speeding?

No: they work in sets of pairs, measuring how long you take to cover a certain distance – though they can be hard to spot, so you may not have seen that you have passed more than one average camera.

Can average speed cameras catch you on your phone?

No: police have been trialling cameras that can detect speeding as well as drivers using handheld mobiles, but these are fixed, not average units – for now at least.

How can I avoid getting a ticket from an average speed camera?

By sticking to the speed limit.

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