National Highways has announced it is introducing a weight limit on the M48 Severn Crossing for heavy goods vehicles, in a move that it hopes will ‘future-proof’ the bridge.
Following recently conducted safety inspections that showed deterioration to the supporting cables, the new restrictions, which will come into effect from 27 May 2025, will mean that only vehicles weighing 7.5 tonnes or less will be permitted to use the crossing.
All vehicles that surpass this weight can still use the Prince of Wales Bridge when travelling between England and Wales.
Programme delivery manager for National Highways, Chris Pope, said: ‘Safety is our number one priority, and this weight restriction is about future-proofing the bridge 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.
‘As with all our structures, we will continue to monitor the bridge and ensure it remains safe for users.’
In 2024, the M48 Severn Bridge was used by around 32,000 vehicles a day, including 3,270 which weighed over 7.5t.
This suggests around 10% of the bridge’s traffic will have to be diverted via the M4 Prince of Wales Bridge following the new restrictions.
This is not the first time that the suspension cables have caused concerns; the M84 Severn Bridge has undergone several major assessments and subsequent interventions due to worries over corrosion and strength reduction in the cables.
The latest one, which was conducted in 2022/23 and finalised in December 2024, showed that the main cables were deteriorating and had reduced in strength.
The M48 Severn Bridge will remain open to all emergency vehicles, along with scheduled buses, coaches, gritters and recovery vehicles.
Automatic Number Place Recognition (APNR) cameras are being explored to support the enforcement of these new restrictions.
