Height limitUnited Kingdom
Traffic rules
United Kingdom
34. Height limit
A height limit prohibits vehicles whose total height exceeds the value shown from entering or passing a road section, bridge, tunnel, gateway or other structure. The vehicle’s height includes its load and any equipment attached above it.
Drivers of high vehicles must know their exact height, observe advance warnings and use an alternative route when necessary. They should never rely only on visual judgement or attempt to pass beneath a structure when safe clearance is uncertain.
Wikimedia.org • Kilnburn
How should you read a low-bridge height restriction in the United Kingdom?
British low-bridge signs may include a mandatory circular height restriction or a triangular warning of available headroom, often with both metric and imperial figures. An overheight vehicle must not pass a mandatory limit. Check whether an arch has different clearance across its width.
🔗 gov.uk • Great Britain Highway Code: Rule 109; mandatory height limits and warning headroom
🔗 gov.uk • DfT Know Your Traffic Signs: low bridge signs (Great Britain)
Vehicles higher than indicated prohibited.
English • GB diagram 629.2A • Maximum height. Vehicles higher than the stated 4.4 m / 14 ft 6 in must not proceed. Include the load when checking height.
Sources
🔗 Commons.wikimedia.org
🔗 Legislation.gov.uk • Traffic Signs Regulations and General Directions • Great Britain
🔗 Gov.uk • Department for Transport • Know your traffic signs
SVG source: UK Government • Public domain • Original revision 2011-10-29. Wikimedia original unmodified.
Does a roof load count when checking vehicle height in the United Kingdom?
Yes for practical clearance: measure the vehicle at its highest point with its load and fitted accessories, such as a roof box, bicycle or roof rack. Check the local legal measurement rules as well; an empty vehicle’s registered height is not enough when equipment has been added.
🔗 gov.uk • Great Britain Highway Code: Rule 109; mandatory height limits and warning headroom
🔗 gov.uk • DfT Know Your Traffic Signs: low bridge signs (Great Britain)
What should you do if your vehicle is too high for a bridge or tunnel in the United Kingdom?
Do not try to squeeze under the structure. Use the signed alternative route and, if you are already close to the obstruction, stop where safe and seek traffic-control assistance rather than reversing unpredictably into moving traffic.
🔗 gov.uk • Great Britain Highway Code: Rule 109; mandatory height limits and warning headroom
🔗 gov.uk • DfT Know Your Traffic Signs: low bridge signs (Great Britain)
