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decorative image of the A465 section 2

We converted 8km of the A465 between the Glanbaiden junction at Gilwern and the Brynmawr roundabout to 2 lanes in each direction.

Region / County:
south-east Wales
Start date:
end 2014
End date:
late 2023
£336 million
First published:
1 October 2013
Last updated:


Why we did it

The existing A465 was built in the 1960s and is a single three lane carriageway. The road features two lanes in the uphill direction and one in the downhill direction. A regional traffic study in 1990 identified the need to improve this road.

The width of the road restricts traffic flow and opportunities for safe overtaking. In many areas there is poor visibility. Accidents on this stretch are concentrated around junctions and areas with poor visibility.

Improving the A465 is critical to the social and economic regeneration of the Heads of the Valleys area. It will improve access to key services, jobs and markets. This will support inward investment to areas such as the Ebbw Vale Enterprise Zone.


Contractor appointed: 2011
Public information exhibitions: throughout 2011
Statutory process to obtain powers to build the road: autumn 2013 to end 2014
Public local inquiry: spring 2014
Construction began: end 2014
Completion:  Dec 2023
5 year environmental aftercare and defect correction: 2027

What we did

We have:

  • opened the A465 in its final layout in Nov 2021. Some work and maintenance will continue to take place.

Work has been carried out along the length of the scheme to steepen the surrounding ground and so that we can widen the road.

The works included the building of:

  • over 12.5km of retaining walls
  • 16 major structures and
  • 1.3 million m3 of earthworks.  

A total of 55 diversions to Statutory Undertaker apparatus (water mains, gas mains, phone lines and electricity supplies etc.) have been completed. These have included major diversions work to two high pressure gas mains and a water main that required a new 1.5m wide, 100m long tunnel at a depth of 20m below the surface. 100km of BT cables have been installed and over 20km of pipework.

The treatment of a number of old mine workings uncovered near the Brynmawr junction.

The Jack Williams Gateway Bridge was opened to traffic in 2018. The bridge is named after a local World War One hero.

Over 30,000 trees have been planted within the scheme footprint.

We wanted to:

  • reduce congestion
  • reduce queuing during peak times
  • improve air quality
  • reduce driver frustration
  • improving safety
  • improve connectivity
  • improve journey times
  • improve active travel through shared use path for cyclist and walkers
  • improve pedestrian and cyclist crossings.

How we consulted

We consulted on improvements to the A465 between Abergavenny and Hirwaun in 1994 as part of the process to develop the preferred route for the whole project.

In 2011 we held a series of public information exhibitions, presentations to local interest groups and meetings with local landowners and businesses We gathered information at these events to help the team understand how this section fit with local priorities, objectives and policies. This influenced the scheme design.

We held exhibitions of the draft orders in November 2013. These provided details of the final scheme which we then took through the statutory planning process.

An independent inspector held a public local inquiry in March and April 2014, where supporters and objectors to the scheme were able to present their case.

Alternative routes proposed by objectors were considered in a public inquiry alongside our published scheme.


Reports, environmental statements and plans


The legislation required for the project to proceed including drafts for public comment

Help and support

Ask a question about the project or report an issue

You can claim from the 21 November 2022 to 21 November 2028 for land depreciation as a result of this project.

Find out more

Costain have a dedicated community manager and a public liaison officer as part of their site team.

If you have a concern or query, you can contact: 0845 600 2664 (24 hours).