More than 20 million vehicles are expected on UK roads over the festive period resulting in delays of up to four hours, according to new analysis.
The busiest days are predicted to be December 20, 21 and 22 as a surge of drivers get an early start on the Christmas getaway, traffic information supplier Inrix said.
The firm reported that a spike in the number of online shopping deliveries will add to the impact of people visiting friends and families.
Motorways expected to have the worst hold-ups include the M25 anti-clockwise, M1 in both directions and M6 southbound.
Significant delays are also predicted on December 27 as the volume of cars rises due to high street sales and people returning from Christmas breaks.
Inrix analysis of the 2016 festive period showed that traffic peaked at around 5pm on the Friday before Christmas with more than 300 hold-ups recorded.
The company's chief economist Dr Graham Cookson said: "As we head into the Christmas period, when many use the roads to visit family and friends, we advise motorists to use the latest real-time traffic technology to keep up to date with the situation on the roads.
"Drivers would be well advised to take alternative routes or avoid driving during peak times altogether."
Almost 400 miles of roadworks will be lifted by Highways England to ease journeys over Christmas.
The "roadworks embargo" will be in place on motorways and major A roads from 6am on December 22 until 12.01am on January 2.
The Government-owned company responsible for the strategic road network said 99% of carriageways will be open during this period.