Tunnel ahead
A red triangle with a tunnel mouth silhouette warns of a road tunnel. Switch your headlights on (most tunnels require dipped beam by law), remove sunglasses, increase your following distance, and tune your radio if there's a tunnel-radio frequency posted. If a longer tunnel has emergency exits, count the bays as you pass.
- Shape
- Triangular
- Background
- White
- Border
- Red
- Primary symbol
- Other
- Diagram reference
- 529.1
Where you'll see this sign
Motorway and A-road tunnels, urban underpasses of any significant length, and routes through major hills or under rivers.
Test yourself on UK road signs
How well do you really know your road signs? New Driver Hub's free mock theory test pulls from official-style DVSA questions and tells you which signs you keep getting wrong.
