National Highways has reported that two lanes are closed on the M4 westbound between junctions J14 and J15.
Traffic is building up westbound on the M4 due to a collision between J14 (Hungerford) and J15 (Swindon).
There are currently delays of one hour against traffic and the event is not expected to clear before 5pm.
Swindon Police have posted : “Please avoid the M4 between Membury Services to Junction 15.
We have reports of five miles of static traffic on this stretch of the motorway following a road traffic collision at about 1.30pm.
Emergency services are currently attending the scene.
Thank you for your patience.”
Updates to follow.