There are a lot of road signs, and trying to learn them one by one is slow. The good news is that the UK system follows a few simple rules about shape and colour. Learn those first and you can work out what most signs mean before you've even read the symbol, which is exactly what you need when a theory test question shows you one you don't recognise.
Rule one: the shape tells you what kind of sign it is
Circles give orders
Something you must or must not do. A speed limit, no right turn, no entry.
Triangles warn
Something ahead you need to be ready for. A bend, a junction, a school, a level crossing.
Rectangles inform
Directions and information. Where a road goes, a lane layout, parking, a hospital.
Two signs break the shape rules on purpose, so they can be recognised even when covered in snow or seen from behind: the eight-sided STOP sign and the upside-down triangle of GIVE WAY. Both mean you have to give way, and STOP means you must stop completely, even if the road looks clear.
Rule two: the colour of a circle tells you which kind of order
- A red ring means you must not. No overtaking, no U-turns, no vehicles over a certain weight, maximum speed 30 mph. The red ring is the prohibition.
- A blue circle means you must. Turn left ahead, keep left, minimum speed, route for buses and cycles only. Blue circles are positive instructions.
This is one of the most commonly confused areas in the test. A blue rectangle gives information, but a blue circle gives an order. A blue circle with "30" is a minimum speed limit, not a maximum.
Rule three: on direction signs, the colour tells you the type of road
| Background | What it shows |
|---|---|
| Blue | Motorways, and routes on the approach to them |
| Green | Primary routes, the main A roads between towns |
| White | Non-primary and local routes |
| Brown | Tourist attractions and facilities |
| Yellow or black and yellow | Temporary signs, such as diversions and roadworks |
A blue background also appears on local signs for things like parking, but on a direction sign pointing to a destination, blue means motorway.
The signs people mix up
No entry and no vehicles
No entry is a solid red circle with a white horizontal bar. No vehicles is a white circle with a red ring and nothing inside it. They look alike at a glance, but no entry is about direction: you can't go in this way. No vehicles means no vehicles at all, except pedal cycles being pushed.
No waiting and no stopping
Both are blue circles with a red border. No waiting has a single red diagonal line. No stopping, used on clearways, has a red cross. Remember it as one line, you can stop briefly; two lines, you can't stop at all.
The national speed limit sign
A white circle with a black diagonal stripe means the national speed limit applies. It doesn't tell you a number, so you need to know it for the road and vehicle. For a car, that's 60 mph on a single carriageway and 70 mph on a dual carriageway or motorway. It's lower for some vehicles, such as cars towing caravans or trailers.
Built-up areas
Where there are street lights and no other signs, the limit is generally 30 mph in England and Scotland. In Wales, the default on these roads is 20 mph. The test may ask about the limit on a road with street lights, so remember it can depend on which country you're in, and that signs always override the default.
End of restrictions
Signs with a black or grey diagonal line through them often mark the end of something: the end of a minimum speed, a zone or a restriction. Look for the diagonal before you decide what a sign means.
Road markings are signs too
Many theory questions are about markings on the road rather than signs on posts. The ones worth knowing well:
- Double white lines in the centre. If the line nearest you is solid, you must not cross or straddle it, apart from a few exceptions such as passing a stationary vehicle.
- Hatched areas. Diagonal white lines separate traffic or protect turning lanes. If the edge is a solid line, you must not enter except in an emergency.
- Zigzags at crossings. White zigzags mean no parking or overtaking near a pedestrian crossing. Yellow zigzags outside schools mean no stopping.
- Yellow box junctions. Don't enter the box unless your exit is clear. You can wait in it while turning right if only oncoming traffic is stopping you.
- Long white lines broken by short gaps. A hazard warning line. The longer the painted section, the more care is needed.
Lights and signals
Traffic lights run in a fixed order: red, red and amber together, green, amber, then red again. Red and amber means stop: don't go until green shows. A flashing amber at a pelican crossing means you may go if the crossing is clear.
On motorways, a red X above a lane means you must not drive in that lane. Signals on overhead gantries can show a lower speed limit, which you must follow.
How to learn them
Group the signs rather than learning them in a list: all the blue circles, all the warning triangles about roads narrowing, all the end-of-restriction signs. Then test yourself the other way round: look at a meaning and picture the sign.
When you're ready, try our free road sign quiz: ten signs at random, with the meaning explained after each answer.
The official reference is the DVSA's Know Your Traffic Signs, which is on GOV.UK and covers every sign in use. Our app has a searchable road signs guide sorted by category, plus the official sign pages, if you'd rather learn on your phone.
Based on the Highway Code and the DVSA's Know Your Traffic Signs.
Sources
Rules and fees can change. If anything here differs from GOV.UK, GOV.UK is right. How we write our guides.