Post-Brexit security checks could see travel delays for all travellers through the Port of Dover and Eurotunnel this Bank Holiday weekend and half-term break.
Some coach passengers faced 15 hour waits at the docks at Easter.
Port of Dover chief executive, Doug Bannister, said it has since taken steps to process up to 5,500 cars and 350 coaches expected on Friday.
The Kent Resilience Forum, a multi-agency emergency planning group, said in a statement: “The passenger forecasts from both Eurotunnel and the Port of Dover indicate an extremely busy period for cross-Channel traffic over the bank holiday weekend at the end of May.
“This also coincides with schools in the UK breaking up for half-term.”
A key issue for Bannister is the time it takes for travellers to pass through border controls following the UK’s departure from the European Union.
The added security needed to check passports by French authorities can take up to 15 minutes for a coach to get through while a car can take 90 seconds.
But it is the coach checks which hold the other vehicles back.
Bannister told the BBC: “Right now, what has to happen is coach passengers need to disembark the coach, present themselves in front of Police aux Frontières to have their passports reviewed, any security questions that need to be asked are asked and the passport is stamped and they get back on the coach.”
“There’s no doubt that the additional checks are a factor in the queues,” he said.