According to figures from the RAC, more than double the number of cars will take to the road over the long weekend than the same period last year.
It is thought that the weaker pound is playing a crucial role in the higher traffic forecasts, with the lower cost of sterling encouraging Brits to stay at home rather than heading abroad.
By contrast, the changeable weather does not seem to have hampered the determination of drivers to enjoy the last long break before Christmas.
But drivers should take the time to consider their travel plans and make simple checks of things like oil, coolant and washer fluid before hitting the road, according to the RAC.
Despite Highways England announcing more than 370 miles of roadworks are to be removed or completed in time for the August bank holiday, data suggests people should still expect queues.
Rod Dennis, Traffic Watch spokesman for the motorist’s champion, said: “Drivers can expect some queues, especially on the busiest routes to the coasts, Lake District and major cities, but by planning ahead and looking at alternative routes they can help alleviate some of the stress that can be associated with long car journeys.”
According to the study of drivers’ plans for the bank holiday, Saturday will be the busiest day, with the number of getaways set to rise by 2.5 million on last year to reach 5 million.
Sunday will also be busy on the roads. The figures show that some 4.4 million leisure journeys will take place, double the number that was predicted last year.
In total, there will be some 20.7 million cars on major roads between 25 and 29 August.
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But drivers may be able to escape the rush by planning their journey before setting out, using tools like the free RAC app available from the App Store or Google Play.
The RAC’s route planner can also help drivers find the best possible way to get to and from their destination.
Rod Dennis said: “It can be a good idea to travel outside peak times. This Friday evening, plus through the day during Saturday and Sunday are likely to be the most hectic with bumper-to-bumper queues expected on some parts of the network, so motorists that start their journey early or much later on each day might be rewarded with a much clearer run on the roads.”