A woman and two children remain critically ill in hospital after an M5 crash that killed four people.
A lorry crashed through the central reservation at about 14:30 BST on Saturday and hit at least two vehicles heading northwards, police said.
Highways England said it expected the northbound carriageway between junctions 16 and 14, just north of Bristol, to remain shut on Sunday.
The southbound carriageway reopened shortly before 06:00.
No details of the four people killed in the crash, which happened between junctions 15 and 14, have yet been released by police.
The injured woman and children were taken to hospitals in Bristol after the crash, where they were described as being in life-threatening conditions.
The driver of the lorry was taken to hospital to be checked over as a precaution.
