Drivers are planning 13 million trips to visit family and friends during the five-day Christmas bubble period, a new survey suggests.
The RAC poll of 1,500 motorists indicated that December 23 will be the busiest day for festive road travel, with 3.1 million journeys.
Christmas Eve and Christmas Day are predicted to see 2.8 million and 2.5 million trips respectively, which is similar to levels seen in recent years.
Many of these are expected to be local journeys.
A further 2.1 million car journeys are expected between December 23 and 27 but respondents were not sure about their exact travel date.
The UK Government and devolved administrations have agreed a temporary easing of coronavirus restrictions, allowing three households to mix in a bubble from December 23 to 27.
People travelling into Northern Ireland to form a bubble can do so between December 22 and 28.
Some 57% of drivers said they are not planning to visit friends or family by car over the festive period.
One in five of those polled cited concerns about coronavirus as the reason for not getting behind the wheel.
The impact of the pandemic on traffic will be most evident after Christmas Day, according to the RAC.
Only 1.6 million trips on Boxing Day are planned, down from an average of 4.5 million over the past five years.
RAC spokesman Rod Dennis said: “The pandemic looks set to have a profound effect on drivers’ plans to see family and friends at Christmas time this year.
“Despite the loosening of restrictions to allow people to meet up as part of festive bubbles, our figures suggest many drivers aren’t keen – with a fifth saying the coronavirus is the reason why they’re not travelling.
“That’s not to say the roads will be empty over Christmas.
“Our research indicates millions of leisure journeys on major motorways and A-roads will still be taken, with 23 December being the focus of what will be a much less pronounced Christmas getaway than we’ve grown to expect.
“An estimated 5.3m trips to see family and friends will take place on Christmas Eve and Christmas Day combined, roughly in line with other years – and we expect many of these to be more local journeys.”
Network Rail chairman Sir Peter Hendy has been appointed Christmas travel tsar to oversee transport plans for the festive period.
Action being taken to smooth journeys includes shortening rail engineering work and longer trains being operated on some routes.
Highways England will remove 778 miles of roadworks from England’s motorways and major A-roads by 6am on December 20 until the early hours of January 4, meaning 96% of its network will be fully open.