The bizarre scene is a government test of its plans for UK border disruption in the event Britain leaves with no-deal.
The trial on Monday is to see if Manston airfield near Ramsgate can function as a mass HGV holding bay to ease congestion on roads to Channel ports.
The first practice run began in rush-hour shortly after 8am, with four convoys leaving at intervals between 8.13am and 8.39am.
The first of the convoys arrived in Dover at 8.52am and lorries are beginning to arrive back at Manston Airport ready for the second trial run due to take place at around 11am.
For the second trial, all 89 lorries are travelling in one convoy to test out a different scenario.
Traffic was unusually light on the route this morning and the owner of one lorry firm suggested this was because it had been publicised beforehand.
Tracey Ives, who owns haulier INT Logistics, said: “The roads were very quiet today.
“I would have thought we would have got a better, more realistic overview of it all if it hadn’t been advertised beforehand.
“It has been on all the media all weekend so everyone was aware it was going on.”
At least one driver taken part has tweeted that he had his “feet up drinking coffee”.
The Independent’s Tom Peck is covering the story from Manston Airport. He said: “In ten years at the Indy, I’ve been taught literally how to ride a bike by an Olympic cycling coach.
“I’ve entered my dog in Crufts. I’ve trained as a Wimbledon ball boy.
“I’ve never been on an assignment anywhere near as stupid as this.”
Up to 150 lorries were expected to take part but a Department for Transport spokesman on Monday morning confirmed 89 had attended.
Drivers taking part are costing the Department for Transport £550 per driver, their spokeswoman has said, meaning a total of £48,950.
Lord Patten said the exercise was “enough to make one weep”, adding the House of Commons must reject as “snake oil” the option of a “managed no-deal” plan and instead vote to extend or revoke Article 50 to allow more time to work out a “sensible” future relationship with the EU.
“If we can’t do that by getting a majority for staying within the single market and customs union, then I think we have no alternative but to go back to the people for another vote,” he said.
He added: “I don’t like referendums, but we got into this miserable shambles because of a referendum, and it may be the only way we can get out of it.”
Theresa May will intensify efforts to win over her Brexit critics and seek fresh guarantees from Brussels ahead of next week’s crunch vote on her deal.
The Prime Minister acknowledged she was “still working on” getting further assurances from the European Union to address concerns about the backstop measure aimed at preventing a hard border with Ireland.
But as MPs returned to Westminster after the Christmas break she was warned that the attitudes of Tory Brexiteers had hardened, with Boris Johnson stating that a no-deal Brexit was closest to what people voted for in the referendum.
The test “seems to be going quite well”, according to a driver taking part in the exercise.
Ben Pearce, who is working for haulier Jempsons, said: “It will give them a fair idea how the traffic will behave if they do use the space as a holding bay.
“If they do say there’s no-deal Brexit and they use Manston, I think it will be busier in this area because there’s one stretch of the route which is a single carriageway that gets quite narrow.”
There was also a problem with congestion around the entrance to the airfield which needs resolving, Pearce added.
He is being paid at his normal rate for taking part in the exercise and added: “It is not too bad just sitting here, drinking my coffee.”
A DfT spokeswoman said: “We do not want or expect a no-deal scenario and continue to work hard to deliver a deal with the EU.
“However, it is the duty of a responsible Government to continue to prepare for all eventualities and contingencies, including a possible no deal.
“We will be testing part of Operation Brock to ensure that, if it needs to be implemented, the system is fully functional.”
Congestion at the Channel ports caused by the reintroduction of customs checks on goods has been one of the most commonly cited negative effects of a no-deal withdrawal from the EU at the end of March.
Also known as Kent International Airport, the site closed in 2014 after owners could not find a buyer.