The great festive getaway will be at its busiest on Friday with the majority of road, rail and air passengers travelling with time to spare before the Christmas holidays.
Drivers can expect the heaviest motorway delays on Friday and into Saturday, while many rail passengers are looking to avoid engineering works that will slice one of the key national arteries – the west coast main line – from Sunday onwards.
The traffic data analysts INRIX expects about 60% of those driving away for Christmas to be braving the wet weather between 4pm and 6pm on Friday, with roads across the south generally busiest, although it forecasts that the most severe delays will be on the M6.
Trafficmaster, for the AA, warns of hotspots on five motorways, where the networks intersect: on the M25 between the junctions with M3 and M40; the M6 between the M6 toll junction and M62; the M1 north of the M25 to Milton Keynes; the M5 between junction 15 for the M4 and junction 18; and the M62 between the M6 and M60 junctions, 10 and 12.
The Highways Agency said it would complete more than 250 miles of roadworks before Christmas, with many repairs also now suspended until 2 January. But works remain in place at 19 locations on main highways, including the M4 near Reading, the M25 near Godstone in Surrey and the M5 outside Bristol.
British Airways and easyJet will carry more than 200,000 passengers between them on Friday.
About 4 million people will go abroad over the festive period. Heathrow and Manchester airports expect to see their busiest day of the holiday periodon Friday, with more than 105,000 people flying from the west London airport.
Gatwick, where air traffic will peak on 23 December, said the top three Christmas destinations this year were Dubai, Edinburgh and the ski hub of Geneva. Eurostar is attributing ski trips for its own bookings peaking on Friday and Saturday for international train getaways, including direct winter services to the Alps.
While the Association of Train Operating Companies stated "the vast majority of people expected to travel by train over the Christmas and new year holiday period should experience no disruption", Virgin Trains and Network Rail said £125m signalling upgrade work over four days would mean no direct trains between London and Manchester or Liverpool and other cities on the west coast mainline after Saturday until 27 December.
A slow service would run on the Chiltern line to Birmingham.
Coach travel could benefit from the Christmas rail disruption; bookings on routes served by West Coast Line trains or CrossCountry trains – where strike action was threatened – are doubling year on year, according to National Express.
Saturday is the most popular travel day for coach passengers. National Express said it had added 10,000 extra seats to the coach network to meet demand. Its services also run on Boxing Day.
In London, a planned tube strike for Boxing Day will cause "significant disruption" to services, according to Transport for London. Arsenal's home fixture has been called off.