HGVs banned from using Severn Crossing on safety grounds

Heavy Goods Vehicles (HGVs) more than 7.5 tonnes will be banned from using the M48 Severn Crossing to minimise further damage to the bridge.

Following safety inspections, deterioration to the supporting cables was identified. 

The weight restriction, which will come into force from Tuesday, May 27, means HGVs will instead need to use the Prince of Wales bridge to travel between England and Wales.

Two lanes on the M48 bridge will remain open to all other vehicles, to ensure the safety of the bridge and reduce the load on the cables.

The HGV ban will need to remain in place for an estimated 12 to 18 months, dependent on further investigations and while National Highways develops and installs a medium-term solution, which will help manage in real-time the number of vehicles over 7.5t using the bridge.

This, it says, will ensure vehicle loads remain within safe limits.

Chris Pope, programme delivery manager at National Highways, said: “Safety is our number one priority, and this weight restriction is about future-proofing the bridge for years to come.

“Whist the bridge remains safe, it was not designed and built for today’s levels or weight of traffic. Vehicles have got heavier and traffic levels have increased significantly over the last 60 years putting greater load on the cables.

“As with all our structures, we will continue to monitor the bridge and ensure it remains safe for users.”

The M48 Severn Bridge carried roughly 32,000 vehicles a day in 2024, 3,270 of which were vehicles more than 7.5t, meaning around 10% of traffic will be diverted via the M4 Prince of Wales Bridge once the restrictions are in place.

Since the bridge opened nearly 60 years ago, the size and weight of HGVs have increased significantly due to evolving transport demands, some rising from 22 tonnes to 44 tonnes.

Traffic numbers have also increased over the decades. Since the tolls were removed on the bridge in 2018, there has been a 34% increase in traffic and these changes mean a substantial increase in weight over the bridge, which it was not designed for, says National Highways.

The M48 Severn Bridge has undergone several major assessments and interventions related to its main suspension cables due to concerns about corrosion and strength reduction, caused by its exposure to harsh weather conditions.

In 2022/23, an assessment of the bridge’s main cables was carried out followed by further laboratory testing.

Finalised in December 2024, the results revealed that the main cables are deteriorating and not as strong.

Due to these results, it was recommended National Highways reduce the load on the bridge to minimise further damage.

Pope said: “We’d like to thank drivers for their support and must stress that only heavy goods vehicles up to 7.5tonnes in weight should use the bridge.

“Continued use of the bridge by heavier heavy goods vehicles could ultimately see it closed to all traffic. We are acting now to prevent this from happening.”

The M48 Severn Bridge will remain open to all emergency vehicles, scheduled buses, coaches, gritters and recovery vehicles.

If there is an unplanned closure of the Prince of Wales bridge, heavy goods vehicles over 7.5t will need to follow the official diversion route via the M5 and the M50.

Automatic Number Plate Recognition (APNR) cameras are being explored to support enforcement of the new weight restriction.