TunnelUnited Kingdom
Traffic rules
United Kingdom
1. Tunnel
A tunnel is a covered passage that carries a road through or beneath an obstacle such as a hill, mountain, building, waterway or another transport route. Road tunnels may contain one or more traffic lanes and can carry traffic in one or both directions.
Driving in a tunnel requires particular attention because visibility, available escape routes and space for avoiding hazards are limited. Drivers should follow the applicable lighting, speed, lane and following-distance rules and pay attention to emergency exits, traffic signals and variable-message signs.
What should I check before entering a tunnel in the United Kingdom?
In Great Britain, follow tunnel signs and use the required lights. Allow at least a two-second gap on high-speed roads and in tunnels where visibility is reduced; a large vehicle in a tunnel should allow four seconds. Double the gap on wet roads and increase it further on ice. If stopped in a tunnel, leave at least five metres ahead.
🔗 gov.uk • Great Britain Highway Code: Rules 109,113–115,124–126; tunnel signs
🔗 gov.uk • DfT Know Your Traffic Signs: warning signs (Great Britain)
Does a tunnel sign in the United Kingdom set a universal speed limit?
No single speed can be read from the tunnel pictogram. Apply the road’s relevant limit and any permanent or electronic speed restriction, and drive more slowly when visibility, queues or another hazard require it.
🔗 gov.uk • Great Britain Highway Code: Rules 109,113–115,124–126; tunnel signs
🔗 gov.uk • DfT Know Your Traffic Signs: warning signs (Great Britain)
Is every tunnel in the United Kingdom open to pedestrians and cyclists?
No. Check the road category and access signs before entering. A motorway tunnel, a vehicle-restricted tunnel and a purpose-built walking or cycling underpass have different access arrangements. Emergency evacuation routes do not establish ordinary public access.
🔗 gov.uk • Great Britain Highway Code: Rules 109,113–115,124–126; tunnel signs
🔗 gov.uk • DfT Know Your Traffic Signs: warning signs (Great Britain)
