The Government spent £200,000 redirecting traffic on the M20- then reversing the change a day later.
Operation Brock, designed to manage traffic congestion on the M20 which leads to Kent’s ports of Folkestone and Dover, came into force at 6am on 28 October.
But the plan limiting trucks to 30mph was dismantled a day later because of the time needed to remove the barriers.
A Freedom of Information (FOI) request submitted by PoliticsHome revealed the cost of activating Operation Brock, which involved putting out 7,500 cones, on 28 October - three days before the UK was due to leave the EU - was £107,000.
A further £88,000 was spent deactivating it on 29 October.
The plan came into action despite the fact that MPs had passed the Benn Act delaying a no-deal Brexit.
Boris Johnson sent a letter to Brussels requesting the Article 50 deadline be extended to 31 January.
After it was accepted by the European Council, Highways England confirmed Operation Brock was being stood down.
Highways England told PoliticsHome: “The costs associated with the activation of the contraflow was £107,847.22.
“Installing and removing traffic management is a significant operation and is a main consideration in any road scheme.
“In the case of Operation Brock it involved installing crossover points in the central reservation, altering the road layout and putting out 7,500 traffic cones and 350 signs.”
The further costs “associated with the deactivation of the contraflow were £88,547.12," it confirmed.
Highways England has been allocated £35million for the operation, £30million for the M20, and £5million assigned to adapting the nearby M26 “as an additional contingency measure”.
It was also put in place back in March ahead of the first Article 50 deadline, but was deactivated three weeks later once the extension to October 31 was agreed.
The party also blew £5m on adverts telling people that Brexit was going to happen on October 31.
The £100 million “Get Ready For Brexit” campaign was launched in September to prepare people and businesses for leaving the EU.
The Cabinet Office spent £4,719,504 on adverts counting down to Brexit day according to government papers and the overall cost is expected to rise when the Government announces how much it spent in October.
Most of the money was spent after the Benn Act.
Meanwhile the government have also been forced to reveal that one million 50p coins to commemorate an October 31 Brexit will be shredded and melted down after Boris Johnson broke his pledge to leave by Halloween .
The Royal Mint will take the humiliating step after the Treasury boasted it would mint three million special coins containing the October 31 date in the days running up to our departure.
Most of the money was spent after MPs voted to effectively block a no-deal exit through the Benn Act, which became law on September 9.
