Friday is expected to be the busiest day for traffic over the festive period as millions of people embark on the Christmas getaway.
The AA predicts about 12 million cars will be on the roads due to a combination of people visiting loved ones, shopping trips and holidaymakers, as well as those travelling to and from work.
It commissioned a poll of more than 19,000 motorists which found that 41% expect to drive more than 20 miles on Friday.
AA patrol of the year John Snowling said: "On Friday, it's likely to be very busy at peak times on the major routes as the Christmas getaway coincides with commuter traffic.
"With Christmas falling on a weekend, many people will start their break from Friday, but almost a third of our members will be making their journey on Saturday and more than a fifth will be travelling on Christmas Day to visit friends and family."
Some 448 miles of roadworks on England's motorways and major roads have been suspended or completed in a bid to reduce disruption during the festive period.
Highways England said this would leave 98% of its network free of roadworks until January 3.
Roadside rescue firm Green Flag estimated almost 500,000 people will break down between December 15 and January 15 - equivalent to one every 11 minutes.
The most common causes are expected to be battery faults with more than 95,000 cases, followed by around 36,000 punctures and 22,000 engine failures.
Green Flag's head of rescue Neil Wilson said: "Many people will be hitting the roads to visit family and friends and with adverse weather conditions, it's important to ensure you have carried out the relevant car safety checks in order to avoid car faults and breakdowns."
Rail passengers face disruption, with the annual festive shutdown meaning no trains will run on Christmas Day, with only certain services on Boxing Day.
A number of lines will be closed for an extended period as Network Rail carries out up to 200 improvement projects costing £103 million.
Work on some schemes will begin on Saturday to give engineers and maintenance teams four days to carry out upgrades before the next working day.
No trains will operate to or from London Paddington between Saturday and Thursday because of work to build Crossrail.
That means the Heathrow Express service between Heathrow Airport and Paddington will be suspended for six days and Great Western Railway trains will terminate at Ealing Broadway.
Passengers travelling in Manchester and Cardiff will also be among the worst affected by engineering work.
Southern has warned passengers to expect a severely reduced and disrupted service between December 31 and January 2 due to a strike by RMT conductors.
It comes as commuters and people hoping to get away for Christmas on Thursday evening were hit by 30-minute delays to services out of Euston because of a trespasser on the line at Hemel Hempstead at around 7pm.
Amid the alterations to rail services, coach operator National Express reported last month that its bookings for Christmas Day are up by more than a third compared with the same point last year while demand for seats on Boxing Day has risen by 19%.
The firm is running its biggest-ever Christmas service, with 50% more coaches on the roads on December 25 this year than in 2015.
Travel association Abta said Friday is expected to be the busiest day for airports as people jet off to spend Christmas overseas.
More than 4.5 million people will head abroad from the UK between December 18 and January 2.
Heathrow said the most popular day for flights in the week leading up to Christmas will be Friday, with over 118,000 departing passengers.