The 13-mile stretch between junctions 8 (Maidstone) and 9 (Ashford) will see the contraflow system implemented as part of Operation Brock.
This is in anticipation of the high number of passengers expected at the Kent ports during the Christmas holiday period.
Operation Brock is a measure to ensure the smooth flow of traffic in Kent in case of disruptions to services across the English Channel.
To safely set up the contraflow, the M20 will be closed overnight between 8pm on December 15 and 6am on December 16.
The closure will affect the London-bound stretch from junction 9 to 8 and the coastbound stretch from junction 7 to 9.
Diversion routes will be in place during the closure.
Drivers are advised to follow these routes rather than their satnav instructions.
Once the M20 reopens on December 16, the Brock contraflow will be active.
HGVs heading for the Port of Dover or Eurotunnel must join Operation Brock at M20 junction 8.
Other coastbound traffic, including local freight and car drivers heading for the continent, should follow the signs and crossover to enter the contraflow on the M20 London-bound carriageway.
Sean Martell, head of service delivery for the South East at National Highways, said: “Our job is to keep the country moving and Operation Brock helps us to do that during particularly busy periods at the ports in Kent.
“If you’re heading to the continent this Christmas our advice is please use our TRIP guidance to help plan your journey, check with your travel operator before setting off, and allow yourself some extra time to reach your destination.
“We work hard to try and avoid disruption and delays, but these things can happen so always remember to carry essential supplies such as food and water and make sure your vehicle has plenty of fuel for your winter travels.”
The contraflow system is part of a series of measures to improve Kent’s resilience and ensure the smooth flow of traffic through the region in the event of disruption to services across the English Channel.
