Quick Read
- A lorry overturned on the M4 westbound near Cardiff, Wales, on Tuesday, January 27, 2026, closing two lanes.
- The Welsh incident caused severe delays, with average speeds dropping to 5-10 mph, but no serious injuries were reported.
- A separate police incident shut down the M4 between Swindon and Chippenham in Wiltshire, England, on the same day.
- The Wiltshire incident resulted in a casualty being rushed to hospital and caused all westbound traffic to halt.
- Both incidents led to extensive congestion and travel disruptions across different sections of the M4 motorway.
CARDIFF (Azat TV) – The M4 motorway experienced severe and widespread disruption on Tuesday, January 27, 2026, following two distinct major incidents in different regions of the United Kingdom. A lorry overturned on the M4 westbound near Cardiff, Wales, causing extensive lane closures and traffic standstill for hours, while a separate police incident between Swindon and Chippenham in Wiltshire, England, brought traffic to a complete halt and resulted in one person being rushed to hospital.
Lorry Overturn Halts Traffic in South Wales
The first incident occurred on the M4 westbound between Junctions 34 (Miskin/Llantrisant) and 35 (Pencoed) in South Wales. Shortly after 10:30 AM, a heavy goods vehicle (HGV) overturned, reportedly coming to rest on its side in the carriageway, with some eyewitnesses suggesting it had crashed into a ditch near Junction 34. South Wales Police confirmed that officers were called to the scene at 9:30 AM. The collision led to the closure of two of the three westbound lanes, resulting in immediate and significant delays.
Traffic monitoring services like Inrix and AA reported miles of congestion, with traffic at a near standstill for hours. As the afternoon progressed and the area approached rush hour, delays intensified. An AA traffic update indicated severe delays of 32 minutes between J32 Coryton Interchange and J35 Pencoed, with average speeds dropping to 10 mph. Later, speeds further decreased to 5 mph between J33 Cardiff West and Services and J35 Pencoed, with delays estimated at 18 to 20 minutes.
South Wales Police issued a statement confirming that no serious injuries were reported in the collision. However, the recovery of the overturned lorry proved challenging due to its location, causing the lane closures to persist longer than expected. Traffic Wales, the Welsh government’s traffic information service, confirmed that lanes one and two remained closed throughout the afternoon as recovery efforts continued. Diversion routes, particularly the A4232, also experienced heavy congestion as motorists sought alternative paths.
Police Incident Shuts Down M4 in Wiltshire
Hours later, a second major incident unfolded on the M4 in Wiltshire, England, causing further widespread disruption. An unspecified police incident led to the closure of the M4 between Junction 16 (Royal Wootton Bassett/Swindon West) and Junction 17 (Chippenham). Reports from motorists indicated that all lanes were stopped, with the westbound carriageway completely blocked.
The incident, which began in the afternoon, brought traffic to a standstill for hundreds of drivers. One motorist, stuck since 3:10 PM, reported seeing numerous police and ambulance vehicles at the scene near the Chippenham junction. Wiltshire Police initially closed the motorway in both directions between junctions 16 and 17. While the eastbound carriageway (from Chippenham to Swindon) was later reopened, severe delays persisted, particularly for westbound traffic. The nature of the police incident was not immediately clear, and Wiltshire Police had not released a full official statement at the time of reporting.
The South Western Ambulance Service confirmed that a casualty was rushed to hospital following the incident. Motorists were strongly urged to avoid the M4 between Swindon and Chippenham due to the ongoing closures and severe queues, which caused delays of over an hour.
Widespread Impact on UK Motorists
The dual incidents on the M4 on January 27, 2026, underscored the vulnerability of major transport arteries to sudden disruptions. From South Wales to Wiltshire, thousands of commuters and commercial drivers faced significant travel delays, highlighting the cascading effect of even localized incidents on the broader road network. The combination of an overturned lorry requiring complex recovery and an unforeseen police operation with reported casualties created a challenging day for traffic management across a substantial portion of the M4 corridor.
The simultaneous occurrence of two unrelated, significant incidents on different stretches of the M4 motorway on the same day is a rare event that amplified the typical challenges of traffic management, necessitating a coordinated response from multiple emergency services and transport agencies across two distinct national jurisdictions within the UK.