AROUND four million Britons will be heading overseas for the Christmas break, with those staying behind having to contend with packed roads and disrupted rail services.

The peak days for those flying off to foreign climes are expected to be Friday, Saturday and Sunday coming up (Dec 20-22), said travel organisation Abta.

It added that the most -popular destinations for sun lovers were the Canary Islands, Tunisia, Morocco and the Cape Verde Islands off western Africa.

For those flying long haul, Dubai, Mexico, Cuba and Kenya are favourite spots, while for skiers Switzerland, France, Austria and Italy are the top spots.

Popular for New Year's Eve breaks are Paris, Edinburgh, Amsterdam, Rome, and Dublin, Abta said.

EasyJet expects its busiest Christmas with more than half a million passengers travelling from the UK and Geneva and Amsterdam among favourite destinations.

The airline said its busiest day was likely to this Sunday, with more than 60,000 people travelling from UK airports, including Southend, on that day alone.

For those holidaying in the UK , London and York are popular along with the seaside resorts of Llandudno in Wales, Torquay and Eastbourne.

Abta said around 360,000 travellers would be flying off from Stansted airport over the Christmas period, with around the same number leaving from Manchester, 175,000 from Luton and 100,000 from Glasgow and Edinburgh airports.

Ryanair is carrying a record three million passengers from December 20 to January 6, while Gatwick Airport will handle an estimated two million travellers between December 13 and January 5.

Also, British Airways said just under two million people will fly with the airline between December 16 and January 5, with this Friday being the busiest day with more than 115,000 travellers flying.

In addition, Channel Tunnel high-speed rail company Eurostar said it will be carrying more than 420,000 people from December 20 to January 3 - an 11% rise on the same period 12 months ago.

In the UK, an estimated £2 billion is being spent on travel to friends and families this Christmas, and the RAC is predicting that 13 million people will take to the roads from December 24-26.

With major engineering projects taking place over the festive period, rail passengers are facing line closures, reduced services and buses replacing trains on a number of routes.

Traffic information company Inrix said the busiest time on the roads was likely to be from noon to 5pm on Friday, with the M25 being the most congested spot.

Inrix warned that journey times could triple at the busiest festive time, with shopping areas being particularly busy this weekend and again on Friday December 27.

Car company Kia predicted that the average family car will be driven 413 miles over Christmas, with a survey of 2,000 motorists showing that 10% make more than 11 trips to stock up on festive food.

For rail travellers, essential engineering work means the axing of all Gatwick Express services from Christmas Day to the end of New Year's Day.

This extensive work will also affect services operated by the First Capital Connect (FCC), First Great Western (FGW) and Southern train companies. Certain trains will not run over the festive period, with bus replacement services operating on some routes.

Engineering work is taking place between Paddington station in London and Slough in Berkshire from December 27 to January 3. This will mean disruption to some FGW services, while some Heathrow Express services will be affected from December 30 to January 1.

FGW passengers will also have to put up with engineering work between Oxford and Hanborough from December 27 to 29, while FGW services and those run by the CrossCountry are being disrupted by engineering work between Reading and Basingstoke from December 27 to 30.

FGW passengers will have to use buses instead of trains between Maidenhead and Marlow from December 27 to 29 due to engineering work, while FGW services will also be disrupted from December 29 to January 3 by engineering work between Reading and Didcot Parkway.

A major £19 million upgrade at Gravesend station in Kent will mean the Southeastern company will not be able to run any trains from or through Gravesend between December 22 and January 5. Buses will replace the Gravesend trains.

The Gravesend work will also affect Southeastern's high-speed services.

Engineering work between Retford and Lincoln and between Gainsborough Lea Road and Lincoln will mean buses replace trains between Doncaster/Retford and Lincoln from December 21 to January 5.

From December 23 to 27 there will be engineering work between Manchester Piccadilly and Manchester Airport stations with lines closed at various times. Buses will replace trains on some routes during this time. There is also engineering work in the Manchester Victoria area which will affect Northern Rail services between December 27 and January 1.

Engineering work from December 28 to 30 will mean East Midlands Trains passengers will have to take buses instead of trains between Spalding and Sleaford in Lincolnshire.

Buses will replace trains on parts of London Overground between December 23 and 27 due to engineering work between Surrey Quays and New Cross Gate/New Cross.

Platforms 1-9 will be closed at London's Waterloo station from December 27 to 29, causing disruptions to services by South West Trains.

First Capital Connect (FCC) said it will not have any services running between Gatwick Airport and East Croydon from December 27 to January 1, and journey times will be extended by 70-90 minutes.

The company added that FCC passengers travelling between Gatwick and London Bridge or Blackfriars will be asked to take a bus between Gatwick Airport and East Grinstead and a Southern service between East Grinstead and East Croydon.

Michael Roberts, director-general of rail industry body the Rail Delivery Group, said of the engineering projects: "A great deal of care goes into minimising the impact of this vital work and to keep people on trains wherever possible.

"By planning ahead, the vast majority of passengers travelling by rail over the festive period can expect to travel without disruption."

Some good news for rail travellers is that there will be a few services on Boxing Day. The Chiltern company will be running trains on December 26 for the first time. Its service will operate for around 12 hours, with the first train northbound from London to Bicester North at 8.15am and the last to Princes Risborough at 6.45pm.

Southbound, the first train will run from High Wycombe to Marylebone station in London at 8.29am and the last will run from Bicester North to Marylebone at 6.57pm.

Also, Southeastern will be running some high-speed services between Ashford in Kent and St Pancras International station in London on Boxing Day.

Trains will operate on a half-hourly basis from 8am to 8pm, with free car parking provided at Ashford and Ebbsfleet in north Kent.

On the Tube there is track replacement work at Earl's Court in west London over the festive period. There will be part closures on the District and Jubilee lines between December 27 and 30, while a section of the Northern line will be shut on December 28 and 29.

The London Congestion Charge for vehicles will be suspended from Christmas Day to the end of New Year's Day.

National Express said coach travel would be at its busiest on Monday December 23 and Friday December 27, with its advanced bookings for the period December 23 to January 1 up 10% on the same period 12 months ago.

Outside London, the most popular destinations are Birmingham, Bristol, Leeds, Manchester, Bournemouth and Cardiff.

The Highways Agency said a total of 300 miles of roadworks on England's motorways and major A-roads will be completed by Monday.

A further 86 miles will be suspended between Monday and January 2, with 47 locations being involved in the suspension of work.

For safety reasons, works will remain in place at 21 locations, including schemes on the M4 near Slough in Berkshire, the M6 near Birmingham, the M1 in Yorkshire, and a northern stretch of the M25 in Hertfordshire.

The AA and traffic information company Trafficmaster said they expect the main getaway will be spread over several days, from tomorrow afternoon until Christmas Eve.

A recent AA/Populus survey of 21,587 AA members found that tomorrow and Monday will be the busiest days, with around two in five drivers travelling more than 20 miles on those days .

This Saturday is set to be the busiest day for shopping or other day trips.

One of the quietest times on the roads is expected to be New Year's Day, while Scots and those from Northern Ireland are set to drive the most miles on New Year's Eve.

VisitEngland said around 20% of the adult population planned to spend at least one night away from home over the festive period, with these trips boosting the UK economy by around £1.9 billion.

Travel search site Skyscanner said countries outside the eurozone were proving popular with Britons wanting to get away for Christmas.

Riga in Latvia, Sofia in Bulgaria and Vilnius in Lithuania are among the hotspots.

British Airways said that last year it saw a huge rise in flight bookings made on Christmas Day and it expects festive fatigue will kick in around 9.31pm on December 25, when thoughts will turn to future holidays.