A section of the M4 eastbound has been closed for an investigation, following a collision in the early hours of Sunday morning.
National Highways said a car left the eastbound carriageway at around 02:00 GMT near Leigh Delamere Services, prompting a road closure between Junction 18 (Bath) and Junction 17 (Chippenham).
National Highways said no timeframe is in place for reopening, but early indications suggest the road will remain closed into Sunday afternoon.
Trapped traffic has been released and a diversion is in place on the A420.
