Why there have been long delays on the M4 around Swansea today

Thursday morning, May 26, saw heavy congestion build during morning rush hour on the M4 eastbound carriageway around Swansea. At their worst, queues stretched from Junction 44 all the way to Junction 48 (Hendy / Llanelli and Forestfach), with a travel time of up to 45 minutes. You can read our live updates as the incident unfolded here.

Emergency repairs from around 6am at Junction 45 A4067 (Ynysforgan) were initially to blame for the congestion, as one lane was closed to allow for this to take place, according to traffic monitoring service Inrix. But these delays were compounded by a one-vehicle road traffic collision that saw a car land on its roof. The incident happened between Junction 45 and Junction 44 Peniel Green Road (Llansamlet).

One lane was closed following the crash to assist with recovery as traffic officers attended the scene. Cameras showed heavy traffic in the area, with one motorist reporting that congestion was also backing down the hill from the Penllergaer turn off around Junction 47, all the way through to Pontlliw.

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Traffic at junction 45 on the M4 eastbound carriage. One lane was closed at the junction from the early morning due to emergency repairs (Traffic Wales)

Traffic at Junction 46 of the M4 eastbound carriageway was also heavy this morning and problems were continuing to persist into the afternoon (Traffic Wales)

Queues stretched as far as Junction 47 (Penllergaer) (Traffic Wales)

Police and the fire and ambulance services all attended the scene after being called at around 7.45am. South Wales Police confirmed that one vehicle was involved in the crash. Mid and West Wales Fire and Rescue Service said crews from Morriston and Port Talbot stations arrived to find one private motor vehicle on its roof.

The Welsh Ambulance Service said it was called at about 7.45am and attended the scene with two ambulances and a rapid response vehicle, and its crews were supported by emergency medical retrieval and transfer service colleagues and a duty operations manager. One person was treated and taken to Morriston hospital. To get more traffic news sent straight to your inbox every single day, click here.

Traffic backed down a hill at Penllergaer all the way through to Pontlliw (Oscar Wright)

An AA traffic map showing queues persisting just before 1pm from Junction 45 to Junction 46 (AA)

A person in a passing vehicle took this picture of an overturned car before junction 43 of the M4. It is unclear if this is related to the incident between Junction 44 and Junction 45 (Supplied)

The vehicle involved in the accident was recovered, and all lanes were re-opened from Junction 44 to Junction 45 at around 9.40am. But delays persisted to just after Junction 48 and through Morriston as one lane remained closed due to the emergency repairs at Junction 45.

The lane was still closed in the afternoon, but congestion had eased at Junctions 44, 47 and 48, with heavy queues remaining from Junction 45 to Junction 46, near Morriston Hospital.

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