M4 Eastbound closed

Motorists are advised to expect delays on the M4 eastbound carriageway between junctions 30 and 29 due to a broken-down vehicle. The affected stretch of road runs from Cardiff Gate to Castleton in South Wales, approximately 10 miles east of Cardiff city centre. The incident occurred at 1:11pm on 14 August 2026 and is expected to be resolved by 2:40pm on the same day.

The Welsh Government has issued a statement confirming a lane closure on the M4 eastbound carriageway, with delays possible for drivers. Motorists are advised to use alternative routes where possible, such as the A48 or A48(M) motorway, and to check traffic apps for the latest updates before embarking on their journey. Road Closures UK recommends that drivers also consider checking the official highways agency website or social media channels for the latest information on this incident.

The affected stretch of road is a key route for commuters and hauliers travelling between Cardiff and the M49 motorway. The incident is expected to cause moderate delays, and drivers are advised to plan their journeys accordingly. Motorists are also reminded to drive safely and to take regular breaks to avoid fatigue.

The highway authority responsible for the M4 motorway is the Welsh Government, which has been working to resolve the incident as quickly as possible. Drivers are advised to follow the instructions of traffic management staff on site and to follow the signs directing them to the nearest exit.

Motorists are also advised to allow plenty of time for their journey and to consider checking the latest traffic updates before setting out. This can be done by checking traffic apps such as Waze or Google Maps, or by following the official highways agency social media channels. Road Closures UK will continue to provide updates on this incident as more information becomes available.

For the latest information on this incident and to plan your journey, visit Road Closures UK, or follow the Welsh Government on social media for the latest updates.