The queuing system for lorries approaching Dover will remain in place until after the Easter bank holiday weekend, it has been announced.
Operation Brock, where lorries heading to Dover queue on one side of the M20, was put in place last week.
It was brought in to deal with heavy congestion exacerbated by P&O Ferries routes being suspended.
The Kent Resilience Forum said Brock will remain in place until after Easter "as a precaution" to manage traffic.
Queues of freight on both the M20 and the A20 heading to the cross-Channel ports again stretched for miles on Tuesday.
Also on Tuesday, the Maritime and Coastguard Agency (MCA) said it had detained the Spirit of Britain, one of the ferries which normally runs on the Dover-Calais route.
An MCA spokesperson said the ship had been detained "due to surveyors identifying a number of deficiencies".
Another P&O Dover-Calais ferry, the Pride of Kent, had previously been detained. Three other vessels have yet to be inspected.
The inspections follow the dismissal of almost 800 P&O staff last month without notice, which sparked widespread condemnation.
A trade body raised "humanitarian" concerns over HGV drivers stuck in lengthy queues without access to basic hygiene facilities, food and water.
Heidi Skinner, from Logistics UK, which represents logistics firms, said: "We are calling for an urgent review into the effectiveness of Operation Brock as a traffic management scheme, and most importantly, the humanitarian issues it raises as HGV drivers are left unable to access basic hygiene facilities, food and drink."
A Kent Resilience Forum spokesperson said for "safety reasons it is not possible to provide welfare on a live motorway where traffic is moving, even if slowly".
However, when cross-Channel freight queues were at a standstill, food and water were provided, the spokesperson added.
Nicola Bell, National Highways' regional director, said: "Our top priorities are to help people complete their journeys and allow local communities and businesses to go about their daily business with minimal disruption.
"We keep the deployment of Operation Brock under continual review."