Operation Stack has been lifted on the M20 after being put in place following delays at the Port of Dover due to industrial action in Calais.
The 24-hour closure of the Port of Calais began at 08:00 BST on Thursday.
Operation Stack is activated on the M20 to allow lorries to line up to enter the port and was lifted at about 03:00 BST, Kent Police said.
The Port of Dover says there may continue to be delays after Calais reopens.
Ferries between Dover and Calais were suspended due to the 24-hour strike by staff at the French port.
Ferry operator DFDS switched one of its Calais ships to the Dover-Dunkirk route to provide extra capacity.
When Operation Stack is in place, freight is separated into two queues on either side of the coast-bound carriageway of the M20 between Junctions 8 and 9.
One lane is used for traffic heading to the Eurotunnel terminal and one lane is for port traffic. The middle lanes are kept clear for emergency vehicles.
Non-freight traffic is diverted off the motorway and onto the A20.