Drivers will face overnight closures, lane restrictions and a 50mph limit on the M20 when work starts on the return of Operation Brock next month.

The dreaded contraflow caused months of frustration last year after a 15-mile stretch between Junction 8 for Leeds Castle and Junction 9 for Ashford was cut to just two lanes.

Now the Department for Transport is preparing to reinstall the system at the end of the year as it gears up for disruption once the Brexit transition period ends on December 31.

When active, the scheme sees one side of the motorway used by HGVs heading to cross-Channel ports, with all other traffic restricted to a 50mph contraflow on the opposite carriageway.

This year, moveable concrete blocks will be used instead of the previous metal barrier that took a month to put in and remove.

The blocks – which bosses say can be installed within hours – will be stored on the hard shoulder so highways chiefs can access them quickly when needed.

But to ensure workers can put them on the hard shoulder safely and check the M20 is ready for the return of the contraflow in December, a temporary steel safety barrier will be used between September and November, reducing the London-bound stretch to just two lanes with a 50mph limit.

Highways chiefs will close the London-bound side overnight, between 9pm and 6am, from Tuesday, September 1 to Friday, September 11, to allow for installation of the steelwork.

It will then be shut again between Monday, November 16 and Wednesday, November 25 so contractors can remove the barrier.

Highways England says closing the road overnight means no full closures in the daytime are needed.

But work to install gates on the central reservation will require some additional overnight closures of the London-bound carriageway and overnight lane closures on the coastbound side.

Bosses say the safety barrier will "gradually be moved up" the motorway as sections of the work are completed and is expected to move along the carriageway once every two weeks.

During the works, the coastbound M20 will remain open, but a 60mph limit restriction will be in place.

Nicola Bell, Highways England South East regional director, says the work has been "carefully planned to avoid closures during the August bank holiday and October half term".

"Road closures are always challenging and we recognise the impact this work will have on the region’s businesses and communities," she said.

"However, this new solution avoids month long closures to install the barrier and by closing the road overnight, we are reducing disruption during busier periods, which is positive for drivers, local businesses and residents.”

When the London-bound carriageway is closed, Highways England says these clearly signed diversion routes will be in place:

• Junction 9 to 8 London bound diversion route: Traffic will be diverted from junction 9 via the A20 to rejoin the M20 at Junction 8.
• Vehicles over 4.7m high need to follow a different route, which is to turn around at Junction 9 to rejoin the M20 towards Dover, then the A20, the A2, then the M2. Drivers should then leave the M2 for the A249, to rejoin the M20 at junction 7 and head back towards junction 8.

Earlier this month, the government launched a consultation on Operation Brock, which will see a specialist 'zipper' machine used this year to put the concrete blocks into place.

The consultation period runs until midnight on Sunday (August 23).

Visit www.gov.uk to take part in an online survey or email OperationBrockSIs@dft.gov.uk

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