Picture credit: Andrew Martin on Pixabay
Heavy goods vehicles have been banned from using The Severn Bridge, after safety inspections revealed deteriorating cables. As of 27th May 2025, vehicles over 7.5 tonnes can no longer use the bridge.
Two lanes remain open to other vehicles, with the HGV ban expected to be in place for 12 to 18 months. During the ban, National Highways will be developing and installing a medium-term solution to make sure bridge safety is maintained.
With vehicles getting heavier, and traffic levels having increased since the bridge’s construction, it makes sense that the cables would be feeling the strain.
The Severn Bridge opened nearly 60 years ago, and in the time since, the size and weight of HGVs has increased. Some have risen from 22 tonnes to 44 tonnes.
Roughly 32,000 vehicles a day used the M48 Severn Bridge in 2024, and roughly 10% of those were classed as heavy goods vehicles. This means that as a result of the ban, approximately 3,200 additional HGVs will now be crossing via the M4 Prince of Wales Bridge each day.
As well as traffic volumes rising over time, the removal of the toll in 2018 has also led to an increase in traffic. The bridge is now bearing much more daily weight than it was designed to handle.
Chris Pope, Programme Delivery Manager for National Highways has been quoted as saying, “Safety is our number one priority, and this weight restriction is about future-proofing the bridge for years to come.”
Lab testing back in 2022 and 2023 showed that the main supporting cables are deteriorating. Cables are the weak point in a suspension bridge, and these cables were spun from 29,000 km (18,000 miles) of wire back in 1966. Although they’ve undergone repairs and strengthening work, the cables have never been replaced.
With its route over the River Severn, close to the Bristol Channel, the bridge experiences harsh conditions, which will also affect the condition of the bridge. Moisture and steel don’t like each other, so that will be another source of deterioration due to corrosion, on top of the fatigue due to the heavy load the cables are bearing.
It will be interesting to see how engineers tackle the bridge’s problems. Bridge maintenance is very technical, and can be repetitive, so we’re lucky that there are structural engineers who are happy to work in that field. I’m much more interested in the creative and innovative work I get involved with on behalf of my clients in the architecture, construction, and property sectors.
As always, if you need any assistance with the structural elements of an upcoming project, please do get in touch.
