M4 junction to close for essential works

Lewis Smith, Local Democracy Reporter

A junction off the M4 in Neath Port Talbot will be subject to intermittent closures and speed restrictions over the coming month while essential works are carried out.

A public notice states that Welsh Ministers have made an order under Section 14 of the Road Traffic Regulation Act to allow work on or near the M4 between Junctions 38 and 41.

The order introduces a temporary prohibition of vehicles on the eastbound exit slip road at Junction 40 (Tai-bach Interchange). The closure will affect the stretch linking the eastbound main carriageway to the circulatory carriageway of Tan y Groes Roundabout.

Drivers travelling eastbound who wish to leave the motorway at Junction 40 will be diverted. The signed alternative route is to continue to Junction 38, exit the motorway, then follow diversion signs to rejoin the westbound carriageway at Junction 39, before proceeding back to Junction 40 via the westbound off-slip.

The notice explains: “The temporary prohibition and restriction, which will be signed accordingly, are expected to come into force at 20:00 on 23 February 2026 and will operate intermittently until 23:59 on 16 March 2026, or until the temporary traffic signs are permanently removed.”

Although the restrictions are only expected to apply during the specified dates, the legal order will remain valid for up to 18 months as a contingency, should the works need to be rescheduled or extended.

The notice adds: “Advance notice of any changes to times and dates will be displayed before any rescheduled work.”

In addition to the slip road closure, a temporary 40mph speed limit will be in place on this section of the eastbound carriageway near Junction 40.

Motorists are advised to plan journeys accordingly and allow extra travel time during the works period.