Signal system considered for Severn Bridge

Twm Owen – Local democracy reporter

A signal system to allow heavy goods vehicles to cross the M48 Severn Bridge could be put in place.

The bridge that connects Wales and England and carried some 32,000 vehicles in 20024, has been closed to vehicles weighing 7.5 tonnes or more since May in a bid to reduce the load on the crossing due to weakening cables.

Lorries, including many needing to access and exit industrial estates in the Chepstow area, have instead had to take a 13 mile detour and use the M4 Prince of Wales bridge.

Solution

Monmouthshire County Council and politicians in Gwent have been calling for a solution to allow heavy goods vehicles to access the bridge with National Highways having said it was working on a medium term and long term solution with the weight restriction having expected to be in place for 18 months.

It has now said it could be lifted by October 2026 by using a signal system to allowe controlled crossings over the structure which first opened in September 1966.

The signal system is intended to control the number of heavy goods vehicles and ensure there are never too many crossing at one time.

National Highways, the UK Government agency responsible for the bridge, has said it is looking at two options at both Junctions one and two, of the M48, to manage loads which would allow HGVs back across the bridge without overloading its cables.

Alan Feist, programme leader for National Highways, said safety has been its “number one priority” and while the bridge “remains safe” it wasn’t designed for the level, or weight, of traffic using the roads today.

Pace

He said: “We appreciate that this has been disruptive for businesses and hauliers, but we have been working at pace on these options and are pleased to be in on track to get HGVs back onto the M48 bridge next year.”

At Junction One, on the English side at Aust, National Highways proposes to route westbound HGVs heading towards Wales off the M48 via the off-slip and on-slip and control re-entry by way of signals.

One option would control access for all vehicles whilst another would have a dedicated HGV lane, controlling access back onto the bridge.

At Junction Two, at Chepstow, the proposal is to either control HGV movements using traffic signals across the roundabout or, like at Junction One, control HGV access from the eastbound on-slip using signals.

According to National Highways for the “vast majority of the time” the system would operate “freely to release HGVs so they are spread out across the length of the bridge and not concentrated in close proximity”. It says this would mean “very little delay” to HGV or car traffic.  The system can also be used to keep HGVs off the bridge if there is a significant incident in the area.

Chepstow Bulwark and Thornwell councillor Armand Watts, who has raised repeated concerns over the weight restriction said it is a vital link and has questioned how National Highways has made decisions related to the bridge, and the length of time taken to announce and implement a way of allowing HGVs to cross.

The Labour councillor said: “If you are a multinational business intending to distribute across Wales, or a Welsh business looking to expand, you are still uncertain about the long term situation and the economic impact on Monmouthshire, Newport and the Cardiff City region, effectively the whole of South Wales.”

Cllr Watts said he believed National Highways had responsed to pressure from Monmouthshire County Council, and other councils in the Cardiff Capital Region, but said there was still uncertainty and a lack of information including how the bridge can operate without restriction in the long term.

Closure

National Highways which has described the signal system as forming “part of a solution that will allow the current weight restriction to be removed” said it now engaging with South Wales Trunk Road Agency, local highways authorities, including Monmouthshire County Council, and several businesses and hauliers in the area, ahead of implementation by October 2026.

The M48 Severn Bridge remains open to all emergency vehicles, scheduled buses, coaches, gritters and recovery vehicles.

If there is an unplanned closure of the Prince of Wales bridge, vehicles over 7.5t need to follow the official diversion route via the M5 and the M50.