Rail passengers are accustomed to crowds and disruption over the festive period, but 2020 will be different from anything that has gone before.

The prospects for the 19 million people in the UK without access to a car look tricky. These are the key questions and answers.

In past years, travel patterns over Christmas and New Year have been easy to predict, There is a surge in long-distance journeys in the build-up to 25 December – usually peaking on 23 December.

On Christmas Eve, there is significantly lower demand, and services tail off towards late afternoon and evening. Almost all trains have reached their final destinations well before midnight.

No trains run on 25 December, and only a handful of services on Boxing Day. Normally the morning of 27 December is busy on long-distance routes – because of the pent-up demand after two days of no trains.

But for the remainder of the year it’s fairly quiet, picking up sharply on 2 January – unless that falls at a weekend, in which case it is the Monday afterwards.

Yes, dramatically so. All travel restrictions will be lifted from 23 to 27 December, with no legal obstacles to travel anywhere in the UK, whether within England, Wales, Scotland and Northern Ireland or between them.

While the coronavirus pandemic is making predictions difficult, it seems certain that 23 December will be the busiest day on the railways (and, incidentally, the roads).

For many people who are travelling for work, it will be a normal day – but much more significant will be the relaxing of travel during the “Christmas Ease” window.

Added to this, Christmas isn’t Christmas without Network Rail engineering works. But work on key projects will make life even trickier for travellers.

Social-distancing measures mean that capacity is being strictly limited, so you should book in advance to be sure of travelling. While in the past rail travellers with open tickets have been able to jump on any train (and possibly have to stand for hours on end), this is not possible during the coronavirus crisis.

GWR, linking London Paddington with Bristol, the West of England and South Wales, is selling good-value Advance tickets up to 1 January 2021. CrossCountry, connecting southwest England with the Midlands, northern England and Scotland, is selling weekday tickets up to New Year’s Day, but Saturday services only up to 12 December and Sundays to 6 December.

On Avanti West Coast, connecting London Euston with the West Midlands, northwest England, North Wales and southern Scotland, at present no Advance tickets have been released.

If you are one of the hundreds of thousands planning to travel on LNER – the main operator on the East Coast main line linking London King's Cross with Yorkshire, northeast England and Scotland – you will need to wait until Friday 27 November to make bookings.

Grand Central and Hull Trains, the two open-access operators on the East Coast main line, are selling Advance tickets up to 24 December. Both have suspended services during England’s lockdown, up to and including 2 December.

For long-distance journeys on the West Coast main link connecting London with the Midlands and northwest England, London Northwestern is offering some unbeatable prices to book now.

For a Christmas Eve journey from Euston to Birmingham New Street, London Northwestern has £7 Advance tickets available on many services – compared with £26 for the cheapest Avanti West Coast fare. The journey takes around two hours, compared with 80 minutes on the Avanti expresses.

For travellers heading further north and west from the capital, the £9 Advance ticket on the 6.36am from Euston to Crewe compares with £57 on Avanti. At Crewe you can connect with Avanti, Transport for Wales and Northern trains – though you will need to buy separate tickets.

Similar deals are available on southbound services, and for intermediate journeys – for example, Milton Keynes Central to Stafford for £6.

The one inter-city link on 26 December is on Chiltern Railways, which has a single round-trip between London Marylebone and Birmingham Moor Street. But the train operator warns: “Train times from Monday 14 December onwards may not be available and current timetables are subject to change, please check back before you travel.”

The UK’s two largest airports, Heathrow and Gatwick, will have services from London Paddington and Victoria respectively.

ScotRail will run some services on 26 December, mainly in the Glasgow area.

Prepare for disruption. Normally demand is light in the week between Christmas and New Year, so Network Rail schedules engineering work accordingly. 

On the East Coast line, the big problem will be the complete closure of London King's Cross between the last trains on the evening of Christmas Eve and the first departures on the morning of New Year’s Eve. Restrictions and disruption will continue until Sunday 3 January.

In addition, work in the Bristol area means that Bristol Temple Meads is cut off to the west, north and east on 27 December, which means there will be no direct trains between the southwest, the Midlands and the northeast.

On the line linking London with East Anglia, passengers for Colchester and Ipswich face travelling from London Liverpool Street to Stansted Airport – from where they will need to travel onwards by bus.

There will be sharply reduced services between London Waterloo – normally the busiest station in Britain for passenger – and Clapham Junction, the busiest for the sheer number of trains from the last trains on Christmas Eve to the first on 4 January. This will affect trains between the capital and Portsmouth, Southampton, Weymouth and Exeter.

“Bookings from December onwards may be subject to service alterations,” warns ScotRail. “Please check the journey time closer to your date of travel.”

Because of this uncertainty, Advance tickets over the festive period are not available.

Note that no ScotRail trains will run on 1 January.

Transport for Wales is not yet selling advance tickets for the festive spell. On the main long-distance link within Wales (which strays into England a couple of times), only full fare tickets at £87 one way are currently available between Cardiff Central and Holyhead.

No trains will run anywhere in Wales on Boxing Day.

The beleaguered cross-Channel rail operator is suffering more than any other train firm in the UK, due to the quarantine restriction the UK government imposes for travellers from all its destinations.

At present Eurostar plans three Christmas Eve trains from London St Pancras to Paris Gare du Nord, with a flat one-way fare of £103.

Remarkably, given the thin traffic, it plans four London-Paris trains on Boxing Day, for £69.

To Brussels there are two trains on 24 and 26 December, with a single departure on each day to Amsterdam.

On most trains there are no restrictions, but ScotRail and LNER have strict no-alcohol policies.

Not if you have any of the symptoms of coronavirus. The governments of the four nations emphasise they are not positively encouraging people to travel. You should consider whether or not your journey is necessary.

Of course if you do travel by rail, you must observe all the protocols – notably wearing a face covering throughout the journey.