A plan to manage traffic congestion on a Kent motorway has come into force as part of plans for a no-deal Brexit.
Operation Brock sees one side of the M20 being used only by HGVs heading to cross-Channel ports.
All other traffic is restricted to a contraflow system on the opposite carriageway.
The traffic measures are designed to keep the M20 open in both directions in case there is disruption to services across the English Channel.
Lorries heading for Europe will face a 30mph limit between junctions eight (Maidstone) and nine (Ashford) on the coastbound carriageway of the M20.
All other traffic on the motorway - including lorries carrying out UK deliveries - must use a 50mph contraflow of two lanes in each direction on the London-bound side of the road.
Under plans for Operation Brock, hauliers could also be sent to a lorry park at Manston Airport, and the M26 could be be closed and used for queuing HGVs in the event of severe disruption.
A Highways England spokesperson said: "We are keeping the deployment of Operation Brock continually under review and are ready to stand it down if it will not be needed.
"Any decision to deactivate Operation Brock will be taken jointly, and we are in constant contact with the government and our partners in Kent."
Highways England said the contraflow takes about 48 hours to both activate and deactivate.
Operation Brock was last put in place in March four days ahead of the first planned Brexit date, but was deactivated three weeks later.