National Highways launches Severn Bridge resurfacing trial on M48

National Highways will trial a new, thinner resurfacing method on a 200-metre west-bound stretch of the severn bridge from Saturday August 1 until Sunday September 27. Drivers using the M48 Severn Bridge will face overnight closures, lane closures, 24-hour weekend closures, and a contraflow during part of the work.

Chris Pope on bridge maintenance

Chris Pope, the programme manager for National Highways, said the work is needed to maintain the bridge. He said: "Many of the motorways and major A roads we manage were built around 60 years ago and need maintenance to ensure they remain fit for purpose for generations to come."

He also warned road users to plan for delays. "We appreciate this trial may cause some delays in the area and we're advising road users to allow extra time for journeys, especially during peak hours," he said.

Severn Bridge traffic changes

The contraflow will run from 8pm Saturday August 8 until 8pm Friday September 18. During that period, there will be a single narrow lane in each direction on the eastbound carriageway, with the speed limit cut to 30mph and average speed cameras installed.

When the bridge is fully closed, diversion routes will run via the M4 Prince of Wales bridge, and access will be maintained to Chepstow throughout the works. Planned lane closures on the Prince of Wales bridge will be kept to a minimum.

Why the trial matters

National Highways says any new surfacing needs to be laid at the same thickness of 35mm. The original bridge design and construction in the 1960s used a hand-laid 35mm mastic asphalt surface, and the bridge was resurfaced with the same thickness between 1989 and 1991.

If the trial works as planned, National Highways says full resurfacing of both carriageways is scheduled for 2027 and 2028. For drivers, the practical step is simple: expect slower journeys, especially during peak hours, and use the M4 Prince of Wales bridge when closures are in force.