Some travellers said they didn't mind the new exit checks.
"I don't think there's a problem, it's even good. You can't go to another country without showing any I.D., so I think it's good," said one traveller.
"That's good, I'm happy with that, makes no difference to me as long as it doesn't add to the queues. Why not," said another traveller.
While no major delays or problems were reported on Wednesday, the real test to the system was yet to come, warned a travel expert.
"The pressure is really going to start building up on busy weekends in summer, when you could see cars start to back up along the M-20, which point I think they may decide to abandon exit checks temporarily," said travel journalist Simon Calder.
The M-20 motorway links London to the Channel ports of Dover and Folkestone where motor traffic can link to France via the Channel Tunnel or via ferries