Third Menai crossing plans revived as ministers announce study into M4 road options

Planning and design work for a third Menai crossing will resume immediately, while an 18-month study will examine road improvements to tackle congestion on the M4 around Newport.

Deputy Minister for Transport Mark Hooper announced the plans in the Senedd alongside shorter-term measures to improve journeys on both routes.

The third crossing proposal, shelved in 2023, will return to development, including work on its design, environmental assessment, business case and statutory approvals. Construction has not been authorised, and no building timetable or updated cost has been announced.

A review of the Menai crossings identified disruption when either existing bridge is restricted or closed as the main concern for communities and businesses on Ynys Môn and across north Wales.

The Welsh Government will continue investing in the maintenance and operation of both crossings, alongside measures on Britannia Bridge including wind deflectors, variable speed limits and other changes intended to reduce disruption.

A proposal to introduce three lanes operating under a tidal-flow system on Britannia Bridge will not proceed after the review identified significant safety and operational concerns.

Mr Hooper said: “People on Ynys Môn and across the north of Wales have waited a long time for greater certainty about the future of the crossings.

“Today we are setting out a clear way forward, with action to improve the resilience of the existing crossings while immediately beginning work to develop a third crossing.”

Around Newport, the Welsh Government has concluded that road improvements are needed alongside public transport and other measures.

A preferred road option will be selected after the 18-month study. No route or scheme has been chosen at this stage.

Ministers will also take forward a five-year programme of shorter-term improvements, including maintenance of the motorway, changes to how it is managed and targeted work on roads and junctions around Newport.

They also want to make better use of alternative routes, including the A465, to reduce disruption to freight journeys.

Public transport measures include support from Transport for Wales to accelerate delivery of Cardiff Parkway and Magor and Undy stations, improve access to Severn Tunnel Junction station and strengthen bus connections between Newport and Cardiff.

Mr Hooper said: “Alongside that work, we are taking action to reduce peak-hour traffic by up to around one in ten vehicles. Every vehicle taken off the road helps on a motorway that is already operating at or beyond capacity at the busiest times.”

Background and context

Plans for a third Menai crossing were shelved in 2023 following the Welsh Government’s roads review. The scheme was then estimated to cost £400m, and deputy climate change minister Lee Waters said it would not happen “anytime soon” because the funding was unavailable. The preferred proposal was for a new four-lane bridge east of Britannia Bridge.

‘Backwards’

The latest announcement also follows a warning from Future Generations Commissioner Derek Walker that the Welsh Government must not “take Wales backwards” in its response to M4 congestion.

Speaking ahead of the Senedd statement, Mr Walker said any new plan must address the climate and nature emergencies.

He said: “The M4 Relief Road was rejected for good reason, with the Well-being of Future Generations Act helping to protect vital natural habitats and prevent huge costs being handed to future generations.

“We cannot solve today’s transport problems with yesterday’s answers and any new plan must again pass the future generations test, delivering better connectivity across Wales, better public transport, more choice for people and solutions that work for communities and nature, not against them.”

The former Labour Welsh Government’s proposed relief road would have created a 14-mile, six-lane motorway south of Newport across the Gwent Levels, bypassing congestion on the existing M4.

Then-First Minister Mark Drakeford rejected the scheme in June 2019, after more than £100m had already been spent on the project.

Its estimated cost had risen to more than £1.6bn, and Mr Drakeford concluded that it would cause irreversible damage to protected wildlife and habitats on the Gwent Levels.

His decision followed a public inquiry in which planning inspector Bill Wadrup concluded that the proposed route between junctions 23 and 29 was in the public interest and that environmental objections had been overstated.

Senedd motion

A Welsh Conservative attempt to revive the project through a Senedd motion was defeated in June 2025, with Plaid Cymru and Labour voting against it.

In June this year, Mr Hooper ruled out reviving Labour’s relief road scheme but said the Plaid Cymru government would consider “all other road options”, including junction closures.

At that point, he said the overall response to Newport’s congestion would be “public transport focused”, in line with the Burns Commission’s 2020 recommendations.