Drivers across Wales faced major travel disruption on Monday, October 26, after multiple accidents and flooding affected the M4 motorway and surrounding roads. Heavy rain created hazardous driving conditions, with long queues, temporary lane closures and diversions reported throughout the morning.
According to WalesOnline’s live updates, incidents occurred near Magor, Pyle and Porthcawl, while flooding affected the A470 and other routes. Motorists were advised to drive carefully and allow extra time for their journeys.
M4 Accidents Cause Traffic Delays
One of the main incidents occurred on the M4 eastbound near Junction 23A at Magor Services, close to the Prince of Wales Bridge. The accident caused significant congestion during the morning commute, with delays initially reaching approximately 50 minutes.
Traffic queues extended towards Junction 25A near Newport. Although conditions gradually improved, drivers continued to experience slow-moving traffic across sections of the motorway.
Another collision was reported on the M4 westbound near Junction 37, serving Pyle and Porthcawl. Traffic was temporarily held while emergency crews attended the scene.
A commuter told WalesOnline that the collision appeared to involve a BMW and a white transit van. The witness reported damage to the central reservation and the BMW. Police and fire crews were reportedly at the scene, while an ambulance had already left.
Heavy rain and surface water made driving conditions more difficult. Traffic Wales South later confirmed that the westbound carriageway near Junction 37 had cleared after earlier delays.
Flooding had also affected the M4 near Junction 44 at Llansamlet, where one lane was temporarily closed. Traffic updates later indicated that the disruption had cleared.
Flooding Disrupts A470 and A48 Routes
The A470 experienced flooding between Upper Boat and Glyntaff, affecting northbound traffic. Lane one was closed, and traffic officers attended the scene. Diversions were subsequently introduced to help drivers avoid the affected section.
Conditions were also difficult around the Bridge Street roundabout in Pontypridd, where vehicles were seen travelling through floodwater.
Meanwhile, the A48 in Carmarthenshire was disrupted by a collision near Nantycaws Junction. Dyfed-Powys Police reported a closure on the eastbound carriageway between Llanddarog and Carmarthen. Diversions were directed through Llangunnor and Nantycaws.
Traffic monitoring services reported continuing congestion, with vehicles moving slowly through the area.
A separate incident involving a fallen tree closed the A478 between Blaenffos and Cardigan earlier in the morning. Dyfed-Powys Police advised motorists to avoid the road and use alternative routes. The road subsequently reopened.
Drivers Urged to Take Care
The disruption followed heavy rainfall and storms over the weekend. WalesOnline reported that 11 flood alerts were in place across Wales during the morning.
Drivers were advised to reduce their speed, maintain a safe distance from other vehicles and avoid travelling through floodwater when its depth was uncertain.
Although several incidents had cleared or improved by late morning, conditions could change quickly. Motorists were encouraged to check Traffic Wales updates before travelling.
This report is based on WalesOnline’s live coverage from October 26, 2026. Drivers should consult current traffic information for the latest closures, diversions and delays.