Travel warning as the M4 Severn Bridge and Tunnel will be closed for works

Travelers on the busiest routes between Wales and England could face disruption in July as both the M4 Severn Bridge and Severn Rail Tunnel close for repairs.

Trains between South Wales and Bristol, London and the south coast of England will be affected by the 16-day closure of the Severn Tunnel between Wednesday 3 July and Friday 19 July.

The M4 Bridge will also close eastbound on Wednesday and Thursday 10 and 11 July – although the original M48 Severn Bridge is to remain open when its side crossing is closed.

Highways England, which maintains the two Severn bridges, has warned commuters and tourists will face delays until the autumn as there will be a two-lane back-up on the bridge so workers can carry out resurfacing work.

It means sometimes in July the only main route between South Wales and South West England will be over the M48 bridge linking Chepstow and Aust.

Highways England said it would also need more overnight closures of the M4 bridge later in the summer and autumn as road resurfacing progresses.

“If you use the bridge this summer, please expect delays and be prepared to use the M48 to help reduce congestion,” the roads agency said.

“Carrying out this work in the summer reduces the risk of the M48 bridge being closed due to weather, providing an alternative route for anyone crossing the river.”

It comes as passengers on trains between South Wales and England face more than two weeks of disruption with the closure of the Severn Tunnel between Wednesday July 3 and Tuesday July 9.

It means travelers on mainline trains between South Wales and London face at least an extra hour on their journey as the service will go through Gloucester and not stop in Bristol.

Network Rail has also warned that there will be a limited rail replacement service running between Newport, Severn Tunnel Junction and Bristol Parkway – without running directly to Bristol Temple Meads.

Engineers will replace four miles (7 km) of track – the entire length of the southern part towards Wales – by installing 66 new tracks.

The team will also install 10,800 sleepers and over 22,000 tonnes of new ballast and remove 21,000 tonnes of waste.

Workers will also replace around 900m (2,950ft) of track at Cattybrook, near Almondsbury, and more than 230m (750ft) of sewer will be replaced at Patchway Gap – between the two Patchway tunnels near Bristol.

The Severn Tunnel will also be closed for further works on the weekends of July 27 and 28 and August 24 and 25.

Music fans attending big outdoor concerts in south Wales in July could be affected getting to and from those shows and have been warned to plan ahead and allow more time for their journeys.

Shania Twain, Sir Tom Jones and Hozier are booked at Chepstow Racecourse on July 5 and July 6 respectively while the Severn Tunnel is closed.

The National, Manic Street Preachers, Suede, JLS, Idles, Noel Gallagher and Madness will also play Cardiff Castle when the tunnel is closed.

Fans attending Rick Astley and the Lightning Seeds at Cardiff Castle on July 10 are being warned that the Severn Tunnel and the M4 Prince of Wales Bridge eastbound to Bristol will be closed after the show.