Speed cameras in the UK come in several types, and they measure speed in genuinely different ways. Knowing which is which matters less for avoiding a ticket than for understanding the road you are on, but the confusion around them produces some persistent and expensive myths, particularly about tolerances and about what happens to a new driver who gets caught.
<div class=”gmp-keyfacts”><p class=”gmp-keyfacts__title”>Key facts</p><ul><li>The main types are fixed, average speed, mobile and traffic light cameras.</li><li>The minimum penalty for speeding is 3 penalty points and a £100 fine.</li><li>There is no legal tolerance above the limit; any published allowance is guidance, not law.</li><li>Average speed cameras measure your speed between two points, not at one.</li><li>New drivers lose their licence at 6 points within the first two years.</li></ul></div>
For learners, one point is worth putting first: penalty points received while learning carry over to your full licence, and they count towards the new driver limit once you pass.
What are the main types of speed camera?
Fixed cameras. Mounted in a housing at the roadside, usually painted yellow, measuring your speed at a single point. Most modern units are digital and rear-facing, though older forward-facing types remain in places. Because they measure one moment, they catch the driver who is over the limit at that spot.
Average speed cameras. A pair or a series of cameras that read your number plate at two points and calculate your average speed over the distance between them. Common through roadworks and on long stretches of motorway and A-road. You cannot brake for these: slowing at each camera and speeding between them still produces an average over the limit.
Mobile cameras. Operated by police or camera partnerships, from a marked van, a car, a motorcycle or on a tripod at the roadside. They can appear anywhere, and often work in locations with a collision history rather than the obvious places.
Traffic light cameras. Positioned at junctions to catch drivers crossing after the light has turned red. Many also record speed, so the same unit can catch both offences.
Specialist cameras. Increasingly used for other offences, including mobile phone use and seatbelt compliance, and for enforcing bus lanes and box junctions.
How do average speed cameras work?
Average speed cameras read your number plate as you pass the first camera and again as you pass a later one, then divide the distance by the time taken. If the resulting average exceeds the limit, an offence is recorded.
Two things follow from that:
- Braking at each camera achieves nothing. The system is not measuring your speed at the camera; it is measuring how long you took to cover the section.
- Changing lanes does not defeat them. Modern installations read across all lanes.
They are used through roadworks in particular because a steady, moderate speed through a contraflow is safer and keeps traffic flowing better than the accelerate-and-brake pattern that fixed cameras encourage. Setting your cruise control slightly under the limit is the simplest way to drive a managed section without thinking about it.
Is there a tolerance on speed cameras?
Legally, no. The limit is the limit, and you can be prosecuted for exceeding it by any amount.
In practice, official National Police Chiefs’ Council enforcement guidance has commonly worked to a margin of 10% plus 2mph, which in a 30mph limit would mean action from 35mph. This is guidance about when to prosecute, not a legal entitlement, it is applied at the discretion of individual forces, and it is not a speed you are allowed to drive at.
Treating that margin as a buffer is a mistake for two reasons. It is not guaranteed, and it means driving at a speed you cannot justify if conditions change. Speedometers also read slightly high by design, so your true speed is usually a little below the number on the dial rather than above it.
The reliable approach is to drive at or below the limit and treat the limit as a maximum for good conditions rather than a target. Our guide to UK speed limits covers the limits that apply to different roads and vehicles, and the national speed limit sign explains the one that confuses drivers most.
What happens if a speed camera catches you?
If a camera records an offence, the registered keeper of the vehicle is normally sent a Notice of Intended Prosecution and a Section 172 request asking who was driving. That request must be answered, and failing to identify the driver is itself an offence carrying 6 penalty points.
What follows depends on the speed and the circumstances:
- A fixed penalty, most commonly 3 penalty points and a £100 fine.
- A speed awareness course, offered in some cases for lower-level offences if you have not attended one recently. Completing it means no points, though you pay for the course. Details are in our speed awareness course guide.
- A court summons for higher speeds, where fines are calculated from your weekly income and the court can impose more points or a disqualification.
Penalty points stay on your driving record for 4 or 11 years depending on the offence, though they are usually only counted towards totting up for 3 years. The penalty points guide explains how the totals work.
Speed cameras and new drivers
This is where the consequences change sharply. Under the New Drivers Act, if you accumulate 6 or more penalty points within two years of passing your first driving test, your licence is revoked. You return to provisional status and must pass both the theory and practical tests again before driving unsupervised.
Two single speeding offences at 3 points each will do it. So will one offence at 6 points.
Points picked up while you are still learning count too. They sit on your record and, once you pass, count towards that two-year total. A learner who collects 3 points before passing is one ordinary speeding offence away from losing the licence they have just earned.
The full mechanics of how points accumulate are in our penalty points guide.
Do speed cameras always have to be visible?
Fixed camera housings in Great Britain are generally painted yellow and are intended to be conspicuous, on the reasoning that a camera that changes behaviour is doing its job better than one that simply collects fines. Signs commonly warn of camera enforcement on a route.
That is policy rather than a legal requirement, and it does not extend to everything. Mobile enforcement does not have to be signed at the point it is operating, and an unmarked vehicle or an officer with a handheld device is perfectly lawful.
The practical conclusion is the obvious one. Anticipating cameras is not a driving skill. Reading the limit for the road you are on is, and it is the habit that will still be serving you when the camera locations change.
If your speed judgement is the thing you are least confident about, that tends to be a road-reading problem rather than a rules problem. Recognising a road type from its layout, lighting and street furniture is something that improves quickly with concentrated practice, which is what an Advanced course is built around for drivers who already have the basics.
Frequently Asked Questions
How much over the speed limit can you go before a camera catches you?
Legally there is no allowance at all: you can be prosecuted for exceeding the limit by any amount. Official National Police Chiefs’ Council enforcement guidance has commonly worked to a margin of around 10% plus 2mph, which would mean action from about 35mph in a 30 limit, but that is discretionary guidance about when to prosecute rather than a speed you are entitled to drive at. Different forces apply it differently and none of it is guaranteed. Since speedometers are designed to read slightly high rather than low, treating the margin as a buffer is riskier than it seems.
Do average speed cameras catch you if you slow down at each camera?
No, and this is the most common misunderstanding about them. Average speed cameras do not measure your speed at the camera itself. They read your number plate at two points and calculate your average speed over the distance in between, so braking as you pass each unit and accelerating afterwards still produces an average above the limit. Changing lanes does not help either, as modern installations read across all lanes. The only way to drive a managed section legally is to keep your average at or below the limit throughout.
Do penalty points from learning carry over when I pass?
Yes. Penalty points received while you are learning stay on your driving record and count towards the New Drivers Act total once you pass your first practical test. If you accumulate 6 or more points within two years of passing, your licence is revoked and you return to provisional status, needing to pass both the theory and practical tests again. This means a learner who already has 3 points is a single ordinary speeding offence away from losing their new licence, which is worth knowing before you assume points now are a minor matter.
Can I take a speed awareness course instead of getting points?
Sometimes. A speed awareness course may be offered for lower-level speeding offences if you have not attended one within the previous three years and your speed falls within the qualifying range for your area. Completing the course means you avoid penalty points, though you pay the course fee yourself and the offence is recorded as having been dealt with. It is offered at the discretion of the police force concerned rather than being something you can request as of right, and it is not available for higher speeds, which are dealt with by fixed penalty or in court.
Are all speed cameras painted yellow?
Fixed camera housings in Great Britain are generally yellow and signed, as policy rather than legal obligation, on the basis that a visible camera changes driving behaviour more effectively than a hidden one. That does not apply universally. Mobile enforcement can operate from marked or unmarked vehicles without warning at the point of use, and handheld devices need no signage at all. Relying on spotting cameras is not a workable strategy: reading the limit for the road you are on is the skill that matters. GetMyPass arranges courses with DVSA-approved instructors who teach road-type recognition properly.