Operation Stack, which closed parts of the M20 to cars for several days, has been lifted, Kent Police has said.
The operation involves parking – or stacking – lorries on the motorway when cross-Channel services are disrupted.
Eurotunnel services have now returned to normal after the backlog was cleared following disruption caused by migrants.
However, DFDS Seaways has suspended services between Dover and Calais due to disruption at the French port.
Lorries have been parked between junctions eight and 11 of the coastbound M20 in Kent on 21 days over the past three months, but Kent Police said on Sunday the operation was no longer required.
The force tweeted: “#OpStack has now been stood down. The #M20 is now open to all traffic. Thank you for your cooperation and understanding.”
Cross-Channel issues remain for DFDS customers as the ferry operator has suspended crossings between Dover and Calais until further notice, stating there is currently “no access” to the French port.
A DFDS spokesman said customers travelling to France were asked to check in as normal to be transferred to a Dover to Dunkirk service.
Those sailing to the UK from France have been advised to travel to Dunkirk, where they will be placed on the next available ferry.
The statement added: “We are working hard with the parties involved to gain access to the port of Calais as soon as possible.”
PO Ferries said it was running full service but with delays of up to 90 minutes.
A PO Ferries spokesman said there were 58 sailings across the English Channel on Sunday, adding: “Things are clearly very busy, but we are doing everything we can to ensure journeys across the Channel are as trouble-free as possible.”
Operation Stack caused major problems for Kent residents, with gridlock on roads surrounding the M20.
Businesses as diverse as hairdressers and osteopaths said customers cancelled appointments because of travel difficulties.
Vanessa Challess, from Maidstone, who is eight months pregnant, said she feared what would happen if she needed to get to hospital in Ashford to give birth.
A contraflow on the M20 could be introduced to keep local traffic moving if Operation Stack is enforced again.
Kent County Council’s cabinet member for transport, Matthew Balfour, said he hoped it would be ready next week.