We are planning to build a new section of motorway south of Newport alongside complementary measures.

First published:
27 September 2017
Last updated:


Project status: planned
Region/county: south east
Start date: end of 2018
End date: end 2023
Cost: approximately £1.3bn
Design Development Team: Costain, Vinci and Taylor Woodrow with consultants Arup and Atkins, supported by environmental consultants RPS.

If we proceed with this project, we will register it with the Considerate Constructors Scheme (external link).

Why we are doing it

Our proposal for a new section of motorway, and complementary measures, is considered to be the sustainable, long-term solution to current social, environmental and economic problems associated with this route. It forms an essential part of our vision for an efficient integrated transport system in South Wales.

It will improve accessibility for people as well as Welsh goods and services to international markets.

Current progress

We have published environmental information, draft Orders and associated reporting for the proposed M4 project.

At the public local inquiry, independent inspectors examined the scope of the scheme, objectors' suggested alternatives and all social, cultural and economic issues. They have heard evidence from technical specialists, supporters and objectors.

The inspectors are considering the Scheme and all suggested alternatives and will report on the findings.


Public Local Inquiry: closing statements were heard 28 March 2018

Following the inquiry, should the decision be made to proceed to construction, the timetable could be as follows:

Start of construction: end of 2018
Completion of new section of motorway: end of 2023

Next steps

The inspectors will report on the findings of the Inquiry and this will inform the final decision on whether to go ahead with construction.

You will be able to view evidence presented to the inquiry on Persona Associates' website (external link).

Contact Brian Greaves about the M4 Newport corridor around Newport project on 029 2069 5650.

Why hold a public local inquiry

At a public local inquiry an independent inspector examines the social, environmental and economic issues and hears evidence from technical specialists, supporters and objectors. The inspector will consider the proposed solution and all suggested alternatives and report on the findings. This will inform the final decision on whether to go ahead with construction.