Why are we asking this now?
Because, unlikely as it may sound, Britain could be on the brink of the biggest rail-building programme since the Victorian era.
Network Rail yesterday announced it was looking at the feasibility of building five new high-speed main routes out of London to cope with soaring passenger demand.
They would run alongside the existing West Coast line to Birmingham, Manchester and Glasgow; the East Coast line to Edinburgh via York; the Great Western to Bristol; the Midland main line to Sheffield and the Chiltern route to Birmingham.
A spokesman for Network Rail explained: "There is a huge case to be made for an expansion of the rail network. All options are on the table looking at how we address capacity issues."
The year-long review will also assess the need for high-speed trains similar to the French TGV services connecting Paris to the Mediterranean.
How has train use changed?
The rail network boomed in the 19th-century as the industrial revolution opened new markets to manufacturers and social mobility increased.
It reached its peak before the First World War, when 23,000 miles of track connected all parts of the country. Gentle decline set in after then as more freight was carried by road and better-off families were able to afford motor cars. Around one billion train journeys were still being made a year when Dr Beeching swung his axe in the 1960s, shutting down thousands of miles of little-used track, forcing people in more remote areas into cars. Use carried on falling throughout the 1960s and 1970s, dropping to a low of 630 million rail journeys in 1983.
Then something unexpected happened and customers started returning to the trains.
In 2003/04 trains carried one billion passengers for the first time in four decades and last year there were almost 1.2 billion journeys – the highest number since 1946 when the rail network was twice as big.
Why the turn-around?
Britain is on the move as a society more than ever before. The number of cars in the country has increased by 16 per cent in a decade and air travel has grown dramatically. Jason Torrance, campaigns director for the Campaign for Better Transport, said: "We're living further away from where we work, where we shop and where our friends are."
Rail has shared in that general increase, despite above-inflation costs of tickets and the strain on an ageing infrastructure. The need to travel – and the rise in most people's disposable income – has outweighed the sheer expense of train tickets not bought in advance. There is also evidence that travellers are tempted to take long rail journeys if services are made luxurious enough. Sleeper trains once seemed a relic of another more relaxed age, but demand for the London-Penzance overnight route has revived to the extent that First Great Western has announced a £2m refurbishment on the service.
Will the boom continue?
Network Rail predicts that numbers of passengers will continue swelling and could reach 1.5 billion passengers over the next decade. The amount of freight carried by train is also forecast to rise sharply as transport companies look for an alternative to congested motorways. That presents the organisation with an acute dilemma: in less than 20 years the current network will be unable to cope. Routes to the north and west of London will be under particular pressure.
Isn't it greener to go by train?
Yes. There are short-term costs – but longer-term environmental benefits – of a massive investment in the rail network.
Encouraging motorists to change their habits and travel by train would be a key way of helping Britain to hit its target for reducing carbon dioxide emissions by 60 per cent by 2050.
Richard Dyer, the transport campaigner at Friends of the Earth, said: "Expanding Britain's railways by building new high speed lines is potentially very exciting – and could play an important role in weaning Britain off fossil fuels and developing a low carbon economy."
He added: "Britain's transport system needs a new direction. It must play its part in tackling climate change and weaning the nation off our addiction to expensive and insecure oil supplies." Developing high-speed rail links would also deter travellers from London from taking to the skies to such relatively close destinations as Manchester, Newcastle and Manchester.
France, Spain, the Netherlands and Germany are all investing in high-speed routes.
Britain currently only has a paltry stretch of such track – the 67-mile Eurostar connection between London and the Kent coast. Its popularity underlines the potential popularity of fast connections between city centres – Eurostar's passenger numbers are up 22 per cent this year.
High-speed links could reduce the journey time to Manchester to just 74 minutes and to Sheffield to 71 minutes.
What is the argument against more train routes?
In a word, the price. Preparing sites and laying track – particularly high-speed connections – are formidably expensive and would daunt all but the most profligate Chancellor. One study suggested building two high-speed links would cost the country £30bn.
The benefits, both in terms of protecting the environment and encouraging economic growth, could be long-term and reaped by future governments.
And the political pain – the pressure on the public finances and the delays and disruption caused by such large building projects – could be short-term.
The environmental benefits of investing in high-speed links – as opposed to conventional rail routes – are also disputed.
Tom Harris, the Rail Minister, has said: "The argument that high-speed rail travel is a 'green option' does not necessarily stand up to close inspection. Increasing the maximum speed of a train from 200kph [125mph – the current maximum speed of trains] to 350kph leads to a 90 per cent increase in energy consumption."
The Liberal Democrats detect government prevarication on the issue. Their transport spokesman, Norman Baker, said: "The rail network is in desperate need of expansion if we don't want to force frustrated passengers back into their cars and on to aeroplanes.
"Instead, the Government has proposed cutting back public funding for the railways, condemning travellers to delay and overcrowding. Its forward plan for rail hits the buffers in 2014."
Is this the age of the train?
* Soaring passenger numbers prove there is a demand for rail travel
* Railways are a low-carbon, environmentally-friendly alternative to polluting cars
* If trains are fast enough, they are much more convenient than air travel
* The British are too fond of the convenience of cars to switch en masse to rail
* The price of tickets is a huge disincentive to train travel – particularly for families.
* Delays and disruption also put off many potential rail passengers