Key points
- The Welsh Government says the Black Route is no longer deliverable.
- An 18-month study will look for a road-based solution, followed by a choice of a preferred option.
- A five-year programme will bring maintenance, junction changes and more freight traffic on the A465.
- About 112,400 vehicles a day used the Brynglas tunnels in 2025; HGVs make up about 14% of peak-hour trips.
- By 2042, peak demand through Brynglas is forecast at 114% of theoretical capacity.
Black Route ruled out
Deputy Minister for Transport Mark Hooper set out the plans in the Senedd on 6 October. According to the Welsh Government, a review found that congestion causes unreliable journeys and that no single measure can solve it. Road improvements are needed, alongside other interventions, and the aim is to remove up to about one in ten vehicles from the motorway at peak hours.
According to Logistics UK, the minister confirmed that the original relief road will not be revived. He said it is no longer deliverable because of the decades of preparation work it would need, and that it would not fix today’s congestion.
The Black Route, a new motorway south of Newport, was cancelled in June 2019 because of its cost, then about £1.4bn, and its impact on the Gwent Levels. The M4 around Newport review estimates that a similar scheme could now cost around £3bn.
18 months of studies, five years of patches
The Welsh Government plans:
- an 18-month study of road-based solutions, after which a preferred option will be chosen,
- a five-year programme covering renewal of the existing motorway, better traffic management, targeted junction and road improvements around Newport,
- freight resilience, with greater use of alternative routes such as the A465 Heads of the Valleys road,
- public transport, including new stations at Cardiff Parkway and Magor and Undy, and better bus links between Newport and Cardiff.
The numbers behind the jam
The review shows why a quick fix is unlikely:
- about 76% of traffic is through traffic that does not stop in the area,
- the Brynglas section carries about 3,200 vehicles per hour, its theoretical capacity,
- bringing the worst sections back within practical capacity would need a 25% cut in peak traffic,
- the best combination of measures assessed would cut M4 traffic by up to 17%, so congestion would probably remain.
The options assessed include widening the Brynglas tunnels (£1.7bn, 12 years), upgrading the A48 and A4810 (£1.8bn, 8 years, 6% less M4 traffic) and closing junctions (£14m, 2 years, 3%). The junction option would mean closing junction 27 fully, as well as the east-facing slip roads at junctions 26 and 25. Promoting the A465 for freight would cost £49m and take three years, but would cut M4 traffic by only about 1%.
Hauliers: a fix is “sorely needed”
Logistics UK welcomed the recognition that a practical solution is needed. Chief executive Ben Fletcher, who met the deputy minister, said: “A long-term solution to alleviate the traffic is sorely needed.” He added that delays on the route affect businesses’ ability to deliver on time.
According to Logistics UK, Plaid Cymru, Welsh Reform UK, the Welsh Conservatives and Welsh Labour all agree that changes are needed around Newport and the Brynglas tunnels.
What it means for hauliers
The M4 is the main freight corridor into South Wales, linking the Severn crossings with Cardiff, Swansea and the ferry ports in the west. Lorries heading to and from Fishguard and Pembroke Dock pass through Newport.
For now, operators should plan for:
- peak delays westbound in the afternoon and eastbound in the morning,
- possible junction changes during the five-year programme,
- more signage and rest areas encouraging HGVs to use the A465.
Lorry restrictions have also affected the M48 Severn Bridge in recent years, as trans.info reported. With a major road scheme at least 18 months away from even being chosen, the Brynglas tunnels will remain one of the UK’s most stubborn bottlenecks for years.
