The Department for Transport is carrying out a live trial of an emergency traffic congestion system to be used in Dover in the event of a no-deal Brexit, with 79 lorry drivers participating.
The trucks started their journey north of the port, at the disused Manston airport near Ramsgate, at 7am on Monday and were due to make their way to Dover.
The challenge facing the government and Kent county council was evident at dawn as an argument broke out between marshals about where the trucks were supposed to go.
In the three-stage process, tests were due to be held again just after 8am at a second holding area on a closed off lane on the southbound carriageway of the A256.
The lorries took an hour to make the 33-mile journey from Manston to Dover, a trip that would normally take about half an hour.
The Road Haulage Association described the test as “window dressing”, saying it could not possibly mimic the reality of 6,000 trucks that would be held at Manston airport in the event of no deal.
The DfT had hoped 150 trucks would take part in Monday’s test, but only 79 turned up, including several from the Eddie Stobart haulage company.
“This is designed to test what happens if there is no deal and Operation Brock is implemented,” said a spokesman referring to the codename for the Brexit traffic management plan.
Kent county council, which is participating in the test, has warned that a no-deal Brexit could result in side roads across the county being backed up with 10,000 trucks a day that use the Dover and Eurotunnel #transport services to France.
It could also result in rubbish not being collected and children being unable to take exams, a 17-page council report warned last month.