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Drivers warned of possible disruption as essential road works take place on M4

15 Jul 2023 2 minute read
The M4 at junction 48. Photo via Google

Motorists are being advised to plan before they travel in the coming months as a series of major road works and lane closures are set to commence on two separate sections of the M4.

Road works between junctions 47 and 49 will take place from August to December.

There will also be diversions in place between junctions 24 and 28 on the eastern side of the Brynglas tunnels in September.

Both projects involve essential maintenance work to ensure the longer term resilience of the road network and to avoid any unplanned emergency repairs.

The repairs will involve the re-waterproofing, resurfacing and replacement of bridge joints to several bridge decks.

Work is taking place during the summer period to minimise the likelihood of delays to the work caused by adverse weather conditions later in the year.


During the works between junctions 47 and 49, the traffic management layout will change to accommodate each phase of the scheme with traffic running in contraflow using the hard shoulder from early September until mid-November.

Lower, mandatory speed limits will also be in place to protect drivers and the workforce during the repairs.

To accommodate works between junction 24-28 a four-weekend and eight-night work programme has been put in place involving full carriageway closures, avoiding simultaneous closure of the eastbound and westbound carriageway.

This could be reduced to two weekends and eight nights depending on weather conditions.

Notification of the works including times for contraflow arrangements will be published on the Traffic Wales website.

The roadworks between junctions 47 and 49 will affect Llanelli Bridge, Morlais Loop Line Bridge, Loughor River Bridge and Swansea & District Line Bridge.

The works between junctions 24 and 28 will affect the Usk Bridge.

The dates earmarked to carry out works between junction 24-28 include:

7th-16th August (weeknights only)
8th to 11th September 2023
15th -18th September 2023
22nd – 25th September 2023
6th – 9th October 2023

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