The London-bound stretch of the A20 near Dover has been shut after an HGV overturned and left the carriageway in the early hours of Sunday.
Kent Police said officers were called at 01:20 GMT to a report of an overturned vehicle and closed the carriageway so the vehicle could be recovered.
The section between the A256 for Dover and the B2011 at Capel-le-Ferne is expected to remain shut for most of the morning, it said.
National Highways said the closure was required to ensure the safety of specialist recovery crews working at the scene.