The eastbound carriageway is shut between junction 15 and junction 14, after an incident before 9am on Thursday, August 6, which brought the motorway to a standstill.
The closure is in place near Membury Services for what has been described as a ‘serious incident’.
Thames Valley Police has been unable to publicly confirm many details at this stage, but passersby say they’ve been left ‘totally shaken’ at the scene.
One eyewitness described the incident to the Swindon Advertiser as a “truly horrific scene”, adding: “We drove past this before anybody was on the scene. I’ve never witnessed anything like this in my life. I’m totally shaken.”
The M4 eastbound has been closed past Swindon (Image: National Highways)
A spokesperson for Thames Valley Police said: “We are currently dealing with a road traffic collision on the M4.
“Junction 15-14 on eastbound, near Membury services is shut. There are significant delays and growing tailbacks in the area, and traffic on the westbound carriageway may also be affected.
“Please avoid the area if possible and consider alternative routes while emergency services work at the scene.
“We will provide further updates when available. Thank you for your patience.”
The M4 eastbound has been closed past Swindon (Image: National Highways)
Eastbound traffic is being diverted off the motorway north onto the A419 and south towards Marlborough. Both of these routes are experiencing delays and increased congestion as a result.
Motorists are urged to avoid the M4 eastbound where possible.
Wiltshire Police has stated that Thames Valley Police is leading the response, and emergency services remain at the scene.
Further information will be released as soon as it becomes available, and the public is asked not to speculate about the incident.
