The air ambulance was called after a driver was left trapped when a van crashed into the central reservation on the M20.
Emergency services rushed to the scene just before 7am this morning following the smash between junction 8 for Leeds Castle and the Maidstone Services, and junction 9 for Ashford.
Traffic was being held in both directions, causing long delays, but all lanes in both directions are now open.
Fire crews used hydraulic cutting gear to free the driver before handing over to the ambulance service.
A police spokesperson said: "Kent Police was called at 6.55am to reports that a van had collided with the central reservation of the M20 coast-bound and the driver was trapped."
Initially there was a lane closure on the London-bound side to allow emergency services access to the trapped driver.
A spokesperson from Secamb said: "At 6.58am we responded with a car and ambulance when a vehicle collided with the central reservation and rolled over.
"The driver was trapped so the road closed and fire called to extricate him. The air ambulance also attended and flew the patient to King’s College Hospital, London, with head and pelvic injuries."
Delays reached up to an hour and 10 minutes on the London-bound side.