Thousands of travellers have hit the UK's roads and railways at the start of the Christmas getaway on what was billed as "frantic Friday".
An estimated 1.3 million Christmas drivers were expected to add to the usual end-of-week traffic.
Bristol Airport cancelled flights after a plane came off the runway and several train lines reported disruption.
However, road delays were less severe than predicted, with the RAC suggesting many may travel on Saturday instead.
Many of Britain's mainline routes will be partially shut in the coming days as Network Rail carries out its biggest ever Christmas engineering programme.
With Paddington station completely closed between Christmas Eve and 27 December, Great Western Railway is urging passengers to get to their Christmas destination by the end of Saturday "at the latest".
Meanwhile, the Association of British Travel Agents said 4.5 million people were expected to travel abroad in coming days.
It said airports, ports and international train stations would be exceptionally busy and advised people to begin their journeys earlier than usual.
About 260 rail engineering projects will cause disruption to trains during the Christmas period.
- Southeastern will not run trains to London Bridge, Charing Cross and Cannon Street between 23 December and 1 January
- The West Coast main line will be halted between Preston and Lancaster from Christmas Eve to 27 December with buses replacing trains
- Other improvements on the same line will mean a reduced service, with longer travel times, to and from London Euston between 24 December to 2 January
- Thameslink services will not run through Central London between 23-29 December
- There will be no Greater Anglia trains between London Liverpool Street and Ingatestone or Billericay from 23 December to 1 January
Earlier South Western Railway blamed sickness among train crew for the cancellation of some services on Friday.
On Southern, there have been delays to journeys between East Croydon and Milton Keynes, Redhill and Reigate, London terminals and Tattenham Corner, and London Bridge and East Grinstead.
ScotRail has been suffering delays and cancellations between Stranraer/Ardrossan Harbour and Kilmarnock/Glasgow Central after a train derailment in a depot.
But Virgin trains as running a full timetable on the West Coast mainline after a planned strike was called off.
Flights in and out of Bristol Airport were suspended after a plane carrying 25 people came off the runway. The runway is now not expected to reopen until 23:00 GMT at the earliest.
A post on the airport's Twitter feed apologised for the disruption and thanked customers for their "continued patience.""
The RAC said: "Friday has turned out to be slightly less frantic than it first looked although things are hotting up this evening as holiday traffic is competing with commuters and commercial traffic."
It said it had attended 9,000 breakdowns - 15% higher than the seasonal norm.
It warned that drivers might have altered their plans, increasing the risk of serious delays on Saturday.
Earlier, the M1 was hit by three serious incidents with a vehicle fire closing three northbound lanes.
The M40 southbound was closed earlier between junction 10 (Brackley) and junction nine (Bicester), after a lorry caught fire.
Witnesses said the vehicle was carrying bottles of beer which exploded due to the heat.
However, according to Highways England, the disruption has now cleared. Some stretches of the M40 remain slow due to road works.
A "roadworks embargo" is in place on English motorways and major A roads until 00:01 on 2 January in a bid to ease festive congestion.
Many lanes are open and temporary speed restrictions are lifted. However, 27 sets of roadworks, covering a total of 122 miles, are staying in place because it would be too dangerous to lift them.
In Wales, no roadworks are taking place over Christmas and the New Year, other than essential or emergency work.
Coach operator National Express is running extra services over the festive period.