Highways bosses are trying out a new moveable barrier on the M20 for the first time.

The system - dubbed Operation Brock - is designed to deal with traffic disruption at the end of the Brexit transition period on December 31.

It sees the coastbound side of the motorway between Maidstone and Ashford used by HGVs heading to cross-Channel ports, with all other traffic restricted to a 50mph contraflow on the opposite carriageway.

Using a 'zipper machine' to put the barrier in place, Highways England closed the motorway for 12 hours from 8pm last night to allow for the concrete blocks to be installed.

The stretch between Junction 7 for Maidstone and Junction 9 for Ashford reopened this morning but will close again at 8pm tonight to allow for another night of preparations.

Bosses will continue to close the motorway overnight until Tuesday, when the barrier will be shifted back to the London-bound hard shoulder.

Costing £55m, Brock is an alternative to Operation Stack, which shut sections of the M20 completely.

The barrier, which is stored on the London-bound hard shoulder when not in use, is being installed and removed during the tests.

It is placed in the middle of the London-bound stretch and is used to create the contraflow, replacing the previous metal barrier that took a month to put in and remove.

Bosses say the blocks can be installed within hours thanks to the specialist ‘zipper’ machine.

It is not the first time a concrete barrier has been used in Kent.

What was called a quick removable barrier was trialled along the M20 back in 2008 but was withdrawn in 2012 after being used just once.

Before the live test began, Highways England said "Operation Brock needs to be active by December 31".

First announced in February, the initial installation of the barrier began in September and has only just been finished with a month to spare before Britain leaves the EU.

After the test, bosses say the motorway "will return to normal" by 8am on Tuesday.

Highways England south east operations director Nicola Bell said: “We have again worked extensively with our partners in Kent and are confident that this test will provide a valuable dress rehearsal into the operation of our Kent-wide port disruption contingency measures.

"The test will help us to fine tune Operation Brock, finding ways to make the deployment quicker whenever the barrier is needed, whether it be in preparation for transition, or other disruption to cross-channel services.

“Operation Brock will keep Kent moving, and we thank road users in advance for their patience while the test is taking place.”

"Testing this barrier now will ensure that if the system is needed it can be quickly and safely deployed"

Transport Secretary Grant Shapps said: “Kent is a critical link to one of our busiest trade routes, and this state-of-the-art technology will ensure that we can keep the local road network moving.

“Testing this barrier now will ensure that if the system is needed it can be quickly and safely deployed, helping drivers get to where they need to be - even in the event of disruption at the end of the transition period and to assist with any other future disruption caused for any reason.”

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