Holidaymakers heading towards the south and south-west of England are facing mounting congestion on the roads.
The AA said its first “amber traffic warning” remains in place until 7pm on Friday after it was extended from 3pm.
The warning will then take effect again between 11am and 3pm on Saturday.
This is due to a combination of the first switchover days for holiday lets during the school summer holidays in England and Wales, a rail strike, the Commonwealth Games in Birmingham, and the start of the Football League season in England.
Fears of a repeat of last week’s horrendous delays on roads approaching the Port of Dover and Folkestone proved unfounded, but queues are building on routes towards the south and south-west of England.
As of Friday afternoon, most of the M25 has been hit with congestion while the M5 heading south-west is seeing start-stop traffic.
Jams are also slow-moving on the westbound sections of the M4 towards Bristol and the other side of the Prince of Wales Bridge heading into Newport and Cardiff.
Meanwhile, major disruption is still being felt on the M55/M6 interchange near Preston, Lancashire, following a lorry fire earlier.
The M42 east of Birmingham, and the M60 and the M62 in Manchester have become hotspots, as well as the A64 into York.
However, the AA said roads into the Port of Dover and Eurotunnel terminal in Folkestone have not been affected by traffic.
As well as taking food and water, some form of entertainment for younger passengers might just hold off a sigh and mutterings of ‘I’m bored!’ for a while
Jack Cousens, AA
Jack Cousens, head of roads policy for the AA, said: “The amber warning has been extended to 7pm tonight as people commuting back from work begin to merge with holidaymakers.
“While this heavy traffic is a frustration for many, those working for the British tourism industry should be delighted that so many want to holiday at home and explore the best Britain has to offer.
“The one shining light has been the South East where both Dover and Folkestone have little to no delays.
“However, tomorrow will be even busier, so drivers planning to hit the road need to be prepared for stop-start traffic.
“As well as taking food and water, some form of entertainment for younger passengers might just hold off a sigh and mutterings of ‘I’m bored!’ for a while.”
Tens of thousands of families saw the start of their cross-Channel journeys ruined last weekend as the roads approaching Dover were gridlocked, leading to delays of several hours.
This was blamed on a shortage of French border officers and a serious crash on the M20.
Drivers travelling in and around Kent are advised to plan ahead as this weekend is likely to be extremely busy
The operation was much smoother on Friday morning, with P&O Ferries saying there were “no queues at border controls and traffic is free-flowing through the port”.
Port of Dover chief executive Doug Bannister said on Thursday that French border controls will be “fully resourced”, which will make a “fundamental difference”.
The port expects to welcome around 140,000 passengers, 45,000 cars and 18,000 freight vehicles between Thursday and Sunday.
National Highways, which manages England’s motorways and major A roads, said: “Drivers travelling in and around Kent are advised to plan ahead as this weekend is likely to be extremely busy.
“Operation Brock contraflow remains in place on the M20 and 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.”