Traffic light cameras: what you need to know

Traffic light cameras: what you need to know
Traffic light cameras at busy junctions play a vital role in keeping our roads safe. But if you’ve accidentally run a red light, it may not be clear whether or not you’ve been caught.

Here we’ll cover what you need to know – from what triggers the cameras, to what to do if you think you’ve been snapped.

How traffic light cameras work

Red light cameras detect vehicles which pass through lights after they’ve turned red by using sensors or ground loops in the road.

When traffic lights are on red, the system becomes active and the camera is ready to photograph any car that passes over the trigger.

It’s an offence for any part of your vehicle to pass the white stop line if a traffic light has turned red.

The vast majority of red light cameras in the UK are made by Gatsometer.

These Gatso RLC 36 units also have built-in radar technology, with dual speed and red light functions, so for the sake of safety and the law, avoid the temptation to put your foot down when they start to change.

Does every traffic light have a camera?

No, but they are quite common. Usually bigger and busier junctions have red light cameras; if a junction is a bit of an accident-prone area, then they're more likely to be installed as well.

The best advice is just to treat every junction as if there are cameras, and be careful not to disobey the lights or drive over the white lines.

Why do we need red light cameras?

All traffic cameras are there for our safety. They’re typically installed in high-risk areas, perhaps where someone has previously been injured or an accident has occurred after a red light was run.

At busy junctions and crossings you’ll often also see smaller cameras on top of the lights themselves. These are there to help monitor traffic and congestion on roads, but do not flash for driving offences.

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Does a red light camera flash?

There’s no guarantee you’ll know you’ve been caught immediately, unless the camera unmistakably flashes.

But traffic light cameras don’t always flash like Gatsometer’s more common yellow box speed cameras, so it can be tricky to judge if you made it through in time.

While Gatsometer cameras will produce a distinctive flash whenever taking a photo, newer versions of the Trevulo-D speed cameras – which can also double up as red light cameras – use an infra-red flash which isn’t visible to the driver.

If your car is captured by either, you’ll receive a Notice of Intended Prosecution (NIP) within 14 days, once the photo has been reviewed.

What happens if you've been caught by a traffic light camera?

The NIP will ask the registered owner to name the offending driver, complete each section and return it within 28 days.

In most cases, the notice will ask for an admission of guilt and order the payment of a fixed penalty fine in place of taking the case to court.

You’ll also have the right to appeal a penalty notice if you feel you had mitigating circumstances for running a red light.

What defences can I use?

In all likelihood, very few. As a ‘strict liability’ offence, you won’t get away with simply insisting you ‘didn’t intend’ to run the light, if photographic evidence proves you did.

The only circumstances which may offer a defence include:

  • Proving you did not go through the red light
  • Proving there was a defect with the light or related signage

Further, special reasons may also be considered by a court and lead to a re-assessment of your punishment.

However, it is unlikely you will be let off for allowing an emergency vehicle to pass.

The cost of running a red light

Aside from the most important cost – the safety of you and other road users – if caught, you’ll be required to pay a fine.

The current penalty for failing to stop for a red light is usually an £100 fine and 3 points on your licence. The points will stay on record for four years.

If you fail to sign or respond to a NIP, or provide the details of the correct offending driver if disputed, you could face prosecution, six penalty points and a maximum fine of £1000.

Most constabularies also offer educational courses to motorists who are caught running a red light.


The RAC also offers dedicated business breakdown services, as well as specialist products like van breakdown cover and legal expenses insurance

Get complete peace of mind at home and at the roadside with RAC breakdown cover today.

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