FOUR months of overnight roadworks on the M4 around Newport for the installation of a new average speed limit on the motorway will begin next week.

The new system forms part of plans to improve travel on the M4, following the decision to abandon the relief road plans last year.

A fixed 50mph network of average speed cameras will replace the current variable speed limit zone.

The work was due to take place earlier this year, but was postponed due to the coronavirus pandemic.


The average speed limit was one of the initial recommendations put forward by the South East Wales Transport Commission, set up by first minister Mark Drakeford to find alternative ways of improving travel in the Newport area.

The commission found that the current variable speed limit "often lead[s] to breakdown of flow on the M4 around Newport, especially on the approaches to the Brynglas tunnels".

While the variable cameras work well during quieter times of the day, the report adds, they have had a "limited impact" on improving traffic flow during peak times, and can cause "harsh" accelerating and braking from some drivers.

The commission is due to present its final report before the end of the year.

Starting on Monday, November 16, there will be daily roadworks on the M4 from Junction 24 (Coldra) and Junction 28 (Tredegar Park).

The work will be carried out overnight on weeknights, between 8pm and 6am, and will affect travel in both directions.

Traffic Wales said the majority of the work will involve closures of specific lanes, but there will be some periods when full carriageway closures are required.

The diversion route for the roadworks will be via the A48 Southern Distributor Road through Newport.

The project is currently scheduled for completion at the end of February 2021.