Drivers are being warned to expect severe queues on the roads with up to 17 million leisure trips by car predicted to be made over the Easter bank holiday weekend.
Major roads in south-west England and some in the Home Counties are likely to experience the worst congestion on Good Friday, according to the RAC and transport analytics company Inrix.
More than double the normal traffic levels are predicted for the A303 westbound near Stonehenge in Wiltshire, the M5 south between Bristol and Bridgwater, and the M25 anticlockwise between Hertfordshire and Surrey.
Queues are likely to be increased by engineering work on the railways, including the closure of London Euston station.
A survey of 2,400 UK drivers commissioned by the RAC suggested 2.7 million car journeys have been planned for Good Friday and Easter Sunday by drivers embarking on day trips or overnight stays.
Saturday and Easter Monday are expected to be slightly less busy, with 2.3 million separate getaway trips on each day.
Many people may be waiting to see what the weather has in store as there is potential for another seven million trips to be staggered throughout the long weekend.
RAC spokesman Rod Dennis said: “With many people keen to make the most of the double bank holiday this Easter weekend, we’re expecting the customary jams across parts of the road network to make this Good Friday a bad Friday for drivers, especially those who are planning on covering longer distances.
“Traffic volumes could be even higher if the sun chooses to make a welcome appearance.
“The South and West are the areas to watch as they’re home to some vital roads responsible for carrying vast numbers of people to the holiday destinations of the West Country.
“Our advice to anyone heading that way is to get on the road as early as possible on Good Friday, or travel on a different day entirely.”
Inrix transportation analyst Bob Pishue said: “We expect a large jump in holiday driving, with most congestion occurring on major roads around urban areas and popular destinations.
“Nationwide, we anticipate travel times during the holiday weekend to increase about 25% compared to normal.
“Knowing when and where congestion will build can help drivers avoid the stress of sitting in traffic.”
Mr Dennis urged motorists to give their vehicles “a bit of TLC before setting out”, such as ensuring tyres are properly inflated and checking levels of oil, coolant and screenwash.
National Highways will temporarily remove more than 1,400 miles of roadworks on England’s motorways and major A-roads by 6am on Thursday until Tuesday April 11.
That means more than 98% of its road network will be free from roadworks.
Network Rail is carrying out more than 600 engineering projects on Britain’s railways over the Easter weekend.
No trains will run to or from London Euston between Good Friday and Easter Monday as the West Coast Main Line will be closed up to Milton Keynes Central.
This will disrupt Avanti West Coast and London Northwestern Railway services, and Caledonian Sleeper trains will use London King’s Cross.
Track and signalling modernisation work on some lines into London Victoria means Southern and Gatwick Express services will not call at the station during the bank holiday weekend.
Some trains will be diverted to London Bridge.
Network Rail said it often schedules major engineering work for bank holidays to minimise disruption for passengers as fewer people travel during those periods.