Starting May 27, 2025, the Severn Bridge, which carries the M48 motorway between South Gloucestershire in England and Monmouthshire in Wales, will no longer permit trucks that weigh 7.5 tonnes or more. The restriction is expected to last 12 to 18 months during major construction work to repair bridge suspension cables that have deteriorated and weakened.
During this period, Trimble is adding a temporary weight restriction for the bridge in its map data. The restriction will be included in the Q2 2025 Europe map data release for CoPilot, PC*Miler Web and Web Services, and Trimble Maps. The map data update is expected to be released on May 27, 2025.
- CoPilot users must install the Q2 2025 map update on their devices in order for the routing algorithm to obey the new weight restriction.
- For PC*Miler and Trimble Maps users, the update will be available immediately upon release if the application’s map data version is set to Current.
The new restriction will cause the Trimble applications to generate HGV (Heavy Duty), MGV (Medium Duty), and some LDV (Light Duty) truck routes that avoid the Severn bridge. Many routes will follow the M4 Prince of Wales Bridge over the Severn Estuary—a diversion of approximately 14 miles.
Are there exceptions to the weight restrictions?
The restriction does not apply to coaches, gritters, recovery, and emergency vehicles. However, Trimble’s map data restriction will be based solely on weight, not the type of vehicle, and any vehicles of 7.5 tonnes or more will be routed to avoid the Severn bridge.
How do I know if my trucks are set to 7.5 tonnes or more in Trimble applications?
- For HGV (Heavy Duty) and MGV (Medium Duty) trucks, the vehicle’s weight will always be more than 7.5 tonnes.
- Using the default LCV (Light Duty) truck profile would not exceed the 7.5 tonne limit. However custom LCV profiles can have weights of up to 15 tonnes so the vehicle routing profile in use should be checked to confirm the actual configured weight.
- Auto and Van profiles are below 7.5 tonnes.
What happens when the M4 Prince of Wales bridge is closed?
Occasional closures of the M4 Prince of Wales bridge, which is the main alternate route, are anticipated during the 12- to 18-month restriction on the Severn bridge. In those cases:
- Applications that subscribe to Trimble’s live traffic service will receive closure updates, and truck routes will also avoid the Prince of Wales bridge. This closure, in addition to the Severn weight restriction, may result in a diversion route of approximately 100 miles via the M5 and the M50.
- However, depending on the type of closure, the M48 Severn Bridge may temporarily reopen to vehicles over 7.5 tonnes. Check with local authorities for specific updates in such cases.