Former airport Manston Airport is being used as a lorry park for a trial run in the UK leaves the European Union with no-deal.
The trial was organised by the Department of Transport and Kent County Council to deal with traffic queuing for border checks at Dover, which could stretch back 29 miles when the UK leaves on 29 March.
Nearly 90 HGVs set off at 08.00h in batches of 25, with the HGVs supposed to use the emergency exit by Jentex on Canterbury Road West but instead left at the other end of the site on to the A299, according the Isle of Thanet News.
The trial will test how the A256 copes with increased lorry traffic, with HGVs travelling 20 miles from Manston to the Port of Dover.
Operation Brock is an updated version of lorry queuing system Operation Stack to deal with a backlog of HGVs.
Phase 1 uses the A20 and Dover and Eurotunnel buffer zones, phase 2 uses the M20 motorway, phase 3 uses the A256 and sends up to 6,000 lorries to Manston, while phase 4 uses the M26 and phase 5 takes traffic out of the country.
The move has been criticised by Rod McKenzie, managing director of policy and public affairs at the Road Haulage Association, who questioned why it had not been done sooner.
On Twitter, he wrote: “As an exercise – fine – but should have been done 9 months ago and repeatedly stress tested – too little too late – window dressing”.