National Highways is offering a solution to ensure there are never too many heavy HGVs using the Severn Crossing. This will enable the current weight restriction to be removed.
At present HGVs weighing over 7.5tonnes are diverted onto the M4 Prince of Wales bridge. To solve this, from next autumn HGVs will leave the M48 at Junctions 1 (westbound) and Junction 2 (eastbound) via the off-slip roads with re-entry controlled by signals on the on-slips.
For the vast majority of the time the system would operate to release HGVs so they are spread out across the length of the bridge and not concentrated together, creating very little delay to HGV or car traffic.
The system can also be used to keep HGVs off the bridge if there is a significant incident in the area. Alan Feist, Programme Leader for National Highways, said: “Safety is our number one priority, and this weight restriction is about keeping the bridge safe for use now and for years to come.
“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.
“We appreciate that this has been disruptive for businesses and hauliers, but we have been working at pace to reach this solution and are pleased to be on track to get HGVs back onto the M48 Severn Bridge next year.”
Roads and Buses Minister, Simon Lightwood, said: “I am pleased to see National Highways making progress to allow HGVs to return to the M48 Severn Bridge next year.
“Safety remains the number one priority, while ensuring this important crossing continues to serve the businesses and communities who depend on it.”
Cabinet Secretary for Transport and North Wales, Ken Skates, said: “We welcome and support the news from National Highways. We will continue to engage with the team as measures to address a longer-term solution for the Severn Bridge weight limit are explored.”
The M48 Severn Bridge carried roughly 32,000 vehicles a day in 2024, 3,270 of which were over 7.5t, meaning around 10 per cent of traffic is currently diverted via the M4 Prince of Wales Bridge with the current restrictions in place.
Since the bridge opened nearly 60 years ago, the size and weight of HGVs has increased significantly due to evolving transport demands, some rising from 22tonnes to 44tonnes.
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.
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 that National Highways reduce the load on the bridge to minimise further damage.
