Hundreds of motorists have been stranded on the A1 in Nottinghamshire after an accident closed the road.
Police said three lorries, a van and a car were involved in a collision on the road near North Muskham at 07:45 GMT.
An air ambulance attended and three people were taken to hospital, but their condition is unknown.
The northbound carriageway reopened after an hour but southbound traffic is likely to be halted for several more hours.