National Highways Unveils Traffic-Control Solution to Reopen Severn Bridge to HGVs

Innovative traffic management system set to restore 24-hour access for heavy goods vehicles on the M48 Severn Bridge while protecting the ageing structure from excessive loading.

National Highways has confirmed it has found a practical solution that will allow heavy goods vehicles to return to the M48 Severn Bridge early next year, marking a significant step towards restoring one of the UK's key strategic freight routes.

The new system is designed to manage the number of HGVs crossing the bridge at any one time, enabling the existing 7.5-tonne weight restriction to be lifted without compromising the structural integrity of the historic crossing.

Under the proposals, HGVs will temporarily leave the motorway via Junction 1 westbound and Junction 2 eastbound, where traffic signals on the entry slip roads will regulate when vehicles rejoin the motorway. By controlling the flow of heavy vehicles onto the bridge, National Highways says the crossing will remain within safe loading limits.

For most of the day, however, traffic is expected to operate normally, with the bridge remaining in free-flow conditions for the overwhelming majority of users.

Weight Restriction Set to End

The preferred solution follows months of discussions with local authorities, businesses and other stakeholders and has been identified as the most effective medium-term option while engineers continue to examine permanent long-term interventions for the bridge.

Further traffic modelling has also produced encouraging results, indicating that restrictions previously expected to affect eastbound HGVs during the morning peak will no longer be necessary.

The change is expected to deliver significant benefits for businesses, freight operators and communities in Chepstow and across the wider region by improving journey reliability and reducing diversionary traffic.

Safety Testing Before January Launch

Although the solution has now been selected, National Highways has confirmed additional testing and safety validation are required before the system can be introduced.

As a result, implementation has been pushed back slightly, with the controlled-access arrangement now expected to become operational in January 2027.

Alan Feist, Programme Manager at National Highways, said the organisation wanted to ensure the innovative system had been thoroughly tested before it entered service.

He explained that extensive commissioning, safety audits and operational checks were essential to guarantee the technology functions reliably while continuing to protect the bridge.

Once operational, the system will allow vehicles over 7.5 tonnes to use the crossing around the clock while carefully controlling the number of heavy vehicles on the bridge at any given time.

Protecting a Historic Crossing

The M48 Severn Bridge, which opened in 1966, is a Grade I listed structure approaching its 60th anniversary.

Its exposed marine environment has accelerated corrosion within the bridge's main suspension cables over many decades, while today's traffic bears little resemblance to the volumes and vehicle weights the structure was originally designed to carry.

Routine inspections and structural assessments identified deterioration within the main cables, prompting National Highways to introduce temporary weight restrictions to reduce loading and safeguard the bridge's long-term future.

The new traffic management system aims to strike a balance between preserving this nationally significant engineering landmark and restoring an essential freight connection across the Severn Estuary until a longer-term engineering solution is developed.