The M4 is closed as emergency services respond to a road traffic collision.
999 crews were called to the motorway westbound between junctions 16 (Swindon) and 17 (Chippenham) at around 5pm this afternoon (Monday).
National Highways say the route will remain closed until around 6.45pm.
The closure is causing major delays on Junction 16, and surrounding roads. Traffic is also queuing between junctions 15 and 16 westbound.
UPDATE 7PM: The carriageway has reopened, with just one lane closed for ongoing vehicle recovery work.
