Two lorries collided on the M1 in Bedfordshire, causing the road to be shut for hours.
The crash at about 06:40 GMT happened on the southbound side between junction 12 at Flitwick and 13 near Bedford.
A spokesman for the East of England Ambulance Service said the air ambulance was sent and two patients were treated at the scene.
The road was closed in both directions but the northbound carriageway reopened at about 13:00.
Motorists were urged asked to use other routes. Supporters travelling to the FA Cup match between Fulham and Aston Villa were earlier advised to use the M40.