Full Breakdown
Welsh Government Begins 18-Month Review of M4 Junction Closures Near Newport
By Drooid · · How we work
Review Overview
The Welsh Government has launched an 18-month programme to examine road-based solutions for chronic congestion on the M4 corridor south of Newport. The review, commissioned after transport consultants AR UP evaluated options, will consider closing junction 27 at High Cross, altering the east-facing slip roads at junction 26 in Malpas, and restricting access at junction 25 in Caerleon. It may also explore widening the Brynglas Tunnels, although any major tunnel project could take around 12 years to complete. The previously proposed “black route” relief motorway south of Newport remains “firmly off the table.”
Options and Expected Impacts
- Junction closures (Option 1.4): Full closure of junction 27 and partial closures at junctions 26 and 25. Estimated capital cost £14 million, delivery timeline two years, and a projected traffic reduction of roughly 3 percent on the M4.
- Tunnel widening: Identified as a possible long-term measure, but with a construction horizon of about 12 years.
- Alternative upgrades (Option 1.2/Blue Route): Major improvements to the A48 Southern Distributor Road and A4810 Steelworks Access Road, part of an £8 billion scheme expected to take eight years and reduce M4 traffic by about 6 percent.
Official Statements & Responses
He described the review as a multi-faceted effort:
- ““This work isn't just one piece of work that makes the difference.” — Mark Hooper, deputy transport minister”
- ““This is one of the most important transport corridors in Wales.” — Mark Hooper, deputy transport minister”
- ““Tunnel widening was one of the points that was considered in this review.” — Brynglas Tunnels. Mr Hooper, deputy transport minister”
Hooper added that any junction closures would be coordinated with Newport City Council, local businesses and residents, and would be paired with improvements to public transport and surrounding road flows.
Criticism & Opposition
Local representatives have voiced strong concerns.
- ““The people of Newport are not to blame for the congestion on the M4.” — Ms Bryant”
She called for the impact assessments and modelling to be published before any decisions are made.
Data & Statistics
- Review duration: 18 months
- Estimated cost of junction-closure option: £14 million
- Projected traffic reduction from closures: ~3 percent
- Tunnel-widening timeline: ~12 years
- Alternative “Blue Route” scheme: £8 billion, eight years, ~6 percent traffic reduction
- Previously scrapped relief road: £1.4 billion, cancelled over cost and environmental concerns
The review will shape the next phase of transport planning for one of Wales’s busiest motorways, balancing short-term relief with longer-term infrastructure ambitions.