Commuters faced long delays on the M4 after a crash left one person in hospital.
Three vehicles were involved in the collision on the eastbound carriageway near junction 33 Cardiff West, at around 06:00 GMT on Thursday.
South Wales Fire Service said one person suffered minor neck injuries.
Following the crash, tailbacks of six miles were reported eastbound, stretching back to junction 35 at Pencoed. They have now cleared.
The Welsh Ambulance Service spokeswoman said one person has been taken to University Hospital of Wales, Cardiff.