Weak bridge weight limit sign: what it means
The weight limit sign means no vehicle over the maximum gross weight shown, here 7.5 tonnes, may go past it. The WEAK BRIDGE plate says why.
What does the weak bridge weight limit sign mean?
Know your traffic signs says this sign bans vehicles over the maximum gross weight shown in tonnes. A plate below may exempt empty vehicles. “mgw” stands for maximum gross weight: the most the vehicle may weigh when fully loaded.
Quick quiz
What does the sign at the top of this page mean?
- No vehicles over the weight shown on the bridge.
- Lorries over the weight shown must not go in.
- No vehicles wider than shown.
Show answer
A. No vehicles over the weight shown on the bridge. No vehicles over the maximum gross weight shown in tonnes (Know your traffic signs). Source: Know your traffic signs: regulatory signs, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
Before old or weak bridges and structures that cannot carry heavy vehicles.
What should you do?
Know your vehicle’s maximum gross weight; it is on the vehicle’s plate and in its documents. Most cars are well under 7.5 tonnes, but large vans, motorhomes and lorries may not be.
What do people get wrong?
Confusing it with the goods vehicles weight limit, which shows a lorry in the circle and only applies to goods vehicles. This one applies to all vehicles.
Common questions
What does mgw mean on a weight limit sign?
Maximum gross weight: the most a vehicle may weigh fully loaded, as set for that vehicle.
Do weight limits apply to cars?
Yes, to any vehicle over the weight shown. Most cars weigh far less than 7.5 tonnes.
Compare with
No goods vehicles over 7.5 tonnes signLorries over the weight shown must not go in.
Width limit signNo vehicles wider than shown.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 3 November 2026 against Know your traffic signs (regulatory signs).
- Know your traffic signs: regulatory signs, GOV.UK
- Traffic sign images, Department for Transport, GOV.UK
Contains public sector information licensed under the Open Government Licence v3.0. Traffic sign images are Crown copyright, from the Department for Transport. Sources and image credits.