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Rules of the Road

UK Road Signs: The Complete Guide

Every category of UK road sign explained — warning, prohibition, mandatory, and information — with the signs most likely to appear in your theory test.

8 min read

UK road signs follow a consistent shape and colour system. Once you understand the system, you can work out what an unfamiliar sign means even if you've never seen it before. Shape tells you the category; colour and symbol tell you the specific instruction.

Warning

Red-bordered triangle

Prohibition

Red-bordered circle

Mandatory

Solid blue circle

Information

Rectangle (blue / green / brown)

Warning Signs

Red-bordered equilateral triangle — white background

Warning signs alert you to hazards ahead. They do not require you to stop or take a specific action — they tell you to be aware and adjust your speed or position for what is coming.

Crossroads ahead

Theory test

A junction where roads cross. Neither driver has automatic priority — approach with caution.

Roundabout ahead

Theory test

Slow down, select your lane, and prepare to give way to traffic already on the roundabout.

T-junction ahead

Theory test

The road ahead ends at a junction. Give way or stop unless signs indicate otherwise.

Bend ahead (left or right)

Theory test

A sharp bend in the direction shown. Reduce speed before the bend — not during it.

Double bend (first to left or right)

Theory test

A series of bends ahead. Adjust speed before the first bend and stay in lane throughout.

Road narrows on both sides

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The road becomes narrower ahead. Reduce speed and be prepared to give way to oncoming vehicles.

Road narrows on right (or left)

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One side of the road narrows. The arrow indicates which side is affected.

Slippery road

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A permanently slippery surface — not just in wet weather. Common near bridges, shaded bends, and treated roads.

Loose chippings

Freshly laid road surface with loose stones. Reduce speed and increase following distance — chips can crack windscreens.

Steep hill downward

Theory test

A steep descent ahead. The gradient percentage is shown. Use a lower gear — do not rely on brakes alone.

Pedestrian crossing ahead

Theory test

A controlled crossing (pelican, puffin, or toucan) is ahead. Be prepared to stop.

School crossing patrol ahead

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A lollipop person operates here. You must stop when they signal — this is a legal requirement.

Children ahead

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A school or playground is nearby. Children may run into the road without warning.

Level crossing without barrier

Theory test

A railway line crosses the road with no barrier or gate. The most dangerous type of level crossing.

Level crossing with barrier

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A controlled crossing. Obey all signals and barriers — never attempt to drive around a closing gate.

Traffic signals ahead

Traffic lights are ahead, often used where signals are hidden beyond a bend or brow of a hill.

Two-way traffic straight ahead

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You are leaving a one-way system. Oncoming traffic will be present — keep left.

Risk of ice

Road surface may be icy. Reduce speed significantly — stopping distances can be up to ten times greater on ice than dry roads.

Prohibition Signs

Red-bordered circle — white background

Prohibition signs tell you what you must not do. Disobeying them is a criminal offence. The symbol or number inside the red ring indicates the specific prohibition.

Speed limit (e.g. 30mph)

Theory test

Maximum permitted speed on this road. Applies until a new speed limit or national speed limit sign is shown.

National speed limit applies

Theory test

White circle with a diagonal bar. This means 60mph on single carriageways, 70mph on dual carriageways and motorways. It does NOT mean unlimited speed.

No entry

Theory test

Vehicles must not enter. Usually at the exit of one-way streets. Entering past this sign is illegal and extremely dangerous.

No right turn

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Right turns are prohibited at this junction. The arrow indicates the banned direction.

No U-turns

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U-turns are not permitted here. Often found on busy roads where a U-turn would be hazardous.

No overtaking

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Overtaking is prohibited. Usually where bends, hills, or road width make it dangerous. Applies until the restriction ends.

No motor vehicles

Cars, motorcycles, and powered vehicles are prohibited. Pedal cyclists and pedestrians may still use the road.

Clearway (no stopping at any time)

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A red X on blue background or red-bordered circle with a red X. Stopping is prohibited at all times, not just during certain hours.

No waiting

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Vehicles must not park here. Brief stopping to set down or pick up passengers may be allowed — check accompanying signs for time restrictions.

Give Way

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An inverted red triangle — unique in the UK road sign system. You must give way to traffic on the road you are joining, but you do not have to stop if the road is clear. The painted Give Way lines on the road (two dashed white lines) mark where you must yield.

Note: Give Way is not a circular sign — its inverted triangle shape distinguishes it from all other prohibition signs and means you can identify it even without reading the words.

STOP

STOP Sign

Theory test

The only octagonal road sign in the United Kingdom. You must come to a complete standstill at the solid white stop line — even if the road is clear. Slowing down without stopping is an offence.

The octagonal shape is deliberate. It was chosen precisely because no other sign shares it — which means that even if the sign is obscured by snow, ice, overgrown vegetation, or is damaged to the point where the text or colour is no longer visible, the silhouette alone is enough for a driver to know they are at a STOP junction.

Theory test: Candidates are often asked to identify the STOP sign from shape alone, or asked why it uses an octagon. The answer is always recognisability under obstruction.

Mandatory Signs

Solid blue circle — white symbol inside

Mandatory signs tell you what you must do. The solid blue circle distinguishes them from prohibition signs (red border on white). The white symbol inside indicates the required action.

Ahead only

You must continue straight ahead. Turning is not permitted at this junction.

Turn left ahead

Theory test

You must turn left at the next junction — not at this point. "Ahead" means the instruction applies to the following junction.

Turn left

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Turn left at this junction. This is an instruction, not a warning — failure to comply is an offence.

Keep left (or right)

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Pass on the side indicated. Used to direct traffic around a central obstruction or refuge island.

Roundabout

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Blue circle with a circular arrow. You are approaching a roundabout — give way to traffic from the right.

Mini-roundabout

Same rules as a roundabout: give way to the right. Never reverse on any roundabout.

Minimum speed

You must not travel slower than the speed shown. Rare in the UK — occasionally seen in tunnels. A diagonal bar through the number ends the restriction.

Information Signs

Rectangle — blue, green, or brown background

Information signs provide guidance rather than instructions. The background colour indicates the road type or purpose: blue for motorways and general information, green for primary A-roads, brown for tourist attractions, white for local directions.

One-way traffic

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All traffic travels in the direction shown. Never drive against the flow. Usually a blue rectangle with a white arrow.

No through road

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The road ahead is a dead end. Shown as a T-bar symbol on a blue background.

Hospital ahead

A hospital is nearby. Avoid unnecessary horn use in these areas.

Motorway (blue background)

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Motorway signs use a blue background. Learners may use motorways only with an ADI in a dual-control vehicle.

Primary route (green background)

A recommended route on a primary A-road. Green background is unique to primary route direction signs.

Tourist attraction (brown background)

Direction sign for a tourist or leisure destination. Brown is used exclusively for this purpose across the UK.

Theory Test: Key Points

Shape tells you the category before you read the sign

Triangle = warning, red-bordered circle = prohibition, solid blue circle = mandatory, rectangle = information. You can eliminate wrong answers on the theory test using shape alone.

National speed limit ≠ "no limit"

A white circle with a diagonal bar means the national speed limit applies — 60mph on a single-carriageway, 70mph on a dual carriageway or motorway. It does not mean there is no limit. This is consistently one of the most misunderstood signs.

The slippery road sign is a permanent warning

The skidding car inside a triangle warns of a permanently slippery surface — not just in wet conditions. Often placed near bridges, shaded bends, or roads treated with surface dressing.

Give Way vs STOP — know the difference

Give Way (inverted triangle): slow and yield if necessary — you may proceed if clear. STOP (octagon): you must physically stop, wheels stationary, even on a clear road. Failing to stop at a STOP sign is an offence regardless of traffic conditions.

Turn left vs Turn left ahead

"Turn left" means turn at this junction. "Turn left ahead" means the instruction applies to the next junction, not the current one. The arrow shape inside the mandatory blue circle shows the difference.

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