There has been concern about the state of the cables that hold up the first Severn Bridge since inspections in 2022/23. Further laboratory testing has revealed that the main cables are deteriorating and not as strong as they need to be to support.
To keep the 60-year-old suspension bridge in operation, National Highways is introducing a 7.5-tonne weight restriction. From Tuesday 27th May 2025 heavy goods vehicles over 7.5 tonnes will to have use the 30-year-old cable-stayed M4 Prince of Wales Bridge to travel between England and Wales.
The weight restriction will remain in place for an estimated 12 to 18 months, depending on further investigations and while National Highways develops and installs a medium-term solution to help manage the volume of heavy traffic.
The M48 Severn Bridge has undergone several assessments and interventions over the years related to its main suspension cables due to concerns about corrosion and strength reduction.
Chris Pope, programme delivery manager for National Highways, said: “Whilst 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 heavy goods vehicles over 7.5-tonnes, meaning around 10% of traffic will be diverted via the M4 Prince of Wales Bridge once the restrictions are in place.
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, for which it was not designed.
The M48 Severn Bridge has undergone several assessments and interventions over the years related to its main suspension cables due to concerns about corrosion and strength reduction.
The bridge will remain open to all emergency vehicles, scheduled buses, coaches, gritters and recovery vehicles.
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