Heavy goods vehicles weighing more than 7.5 tonnes will be permitted to use the M48 Severn Bridge again starting autumn 2026, following the implementation of a new traffic management system designed to maintain safety on the ageing structure.
New Traffic Management Solution
National Highways has confirmed that a 'medium-term solution' will be introduced next autumn to remove the current HGV restrictions that have been in place since May this year. The new system will control the flow of heavy vehicles to prevent too many from crossing the bridge simultaneously.
Under the planned measures, HGVs will exit the M48 at Junctions 1 (westbound) and Junction 2 (eastbound) via off-slip roads, with re-entry to the bridge controlled by traffic signals on the on-slips. This approach aims to spread heavy vehicles across the length of the bridge rather than allowing them to concentrate together.
Bridge Safety Concerns
The restrictions were originally implemented due to deterioration of the bridge's supporting cables. Alan Feist, programme leader for National Highways, explained: "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."
Since the bridge opened nearly six decades ago, HGV weights have substantially increased, with some vehicles rising from 22 tonnes to 44 tonnes. Traffic volumes have also grown dramatically, experiencing a 34% increase since tolls were removed in 2018.
Impact on Traffic and Businesses
The M48 Severn Bridge carried approximately 32,000 vehicles daily in 2024, with about 3,270 of these being over 7.5 tonnes. This means roughly 10% of the bridge's traffic has been diverted to the M4 Prince of Wales Bridge since the restrictions began.
National Highways acknowledged the disruption caused to businesses and hauliers but emphasised they have been "working at pace" to develop this solution. The organisation stated that for most of the time, the system would operate 'freely' to release HGVs with minimal delay to both commercial and car traffic.
The system also includes provisions to keep HGVs off the bridge entirely during significant incidents in the area. The M48 Severn Bridge remains open to emergency vehicles, scheduled buses, coaches, gritters and recovery vehicles regardless of the restrictions.
Welsh transport secretary Ken Skates confirmed that the Welsh Government will continue engaging with National Highways as they explore longer-term solutions for the Severn Bridge weight limitations.
