Just like the economy, the spectre of high speed rail emerges and recedes like boom and bust cycles.
It must be high speed rail season now, as the arguments are stronger and the parties involved more passionate than at any time in the past. And the political will to start building may emerge in time for the next general election.
Last week the transport select committee of MPs slammed the Department for Transport (DfT) for, among other things, dragging its heels on high speed rail.
Such political indecision is at odds with the rail sector and construction in general, which has been buoyed by the opening of High Speed 1 and St Pancras station in November 2007. Arup, Atkins and high speed pressure group Greengauge 21 have all put forward separate plans to build on this success by constructing a new 300-350km/h line, called High Speed 2, to run from London northwards.
Greengauge 21's proposal starts at St Pancras and Heathrow and, in its first phase, only runs to Birmingham.
"It will cost £11bn, which includes the government’s 68% on top for 'optimisation bias'," says Greengauge 21 director Jim Steer.
"Journeys would take 40 minutes between Birmingham and Heathrow, and 45 minutes between Birmingham and St Pancras."
The push to begin planning now is because of the lengthy lead-in times and looming congestion, especially on the West Coast Main Line (WCML).
"Key issues with such a transport project will be a 10-year lead in time, so if the planning started today, the bulldozers would not move in until 2018," says former Railway Forum chairman Chris Green.
Others have more pessimistic time frames.
"Any expansion, even the most optimistic, would see the project started now, and see results by 2025, following a 15 year legislative period, and then construction," says Bechtel rail director Tom McCarthy.
But time frames of this length could cause bottlenecks further down the line.
"Long distance there has been 65% growth in rail travel since 1994, and 25% in the last three years," says Atkins senior managing consultant Michael Hayes.
"Between 2006 and 2021, the demand for the WCML will double. There has been little growth on the WCML up to 2003, but improvements on the line have meant growth is now rapid.
"Because journeys are so heavily skewed towards road, even small shifts from road to rail will quickly achieve a doubling in demand. Oil prices could drive this, achieving this doubling in less than 10 years.
"By 2026 we will be back to where we are today," he says.
Network Rail head of route planning Richard Eccles suggests that new lines could well be High Speed, but a lot more work needs to be done first to cost and appraise alternatives. But his message is clear – High Speed is on the menu.
"There will be a doubling of passengers numbers over the next 30 years - imagine double the number of people at Liverpool Street. What do we do when this arises?
"We have to work to identify whether High Speed has the potential to fill this gap – not by itself, but as a catalyst. There is an opportunity for intervention in the form, of one or more new lines, when all other forms of expansion are exhausted."
The green credentials also stack-up. Steer says the letter sent by Tom Harris to Liberal Democrat MEP Chris Davies, which suggested that High Speed Rail may not be as green as conventional forms is misleading (News last week).
"That disqualifies the evidence and the DfT’s own work – Eddington showed that High Speed will reduce, not increase, carbon emissions. There is a staggering advantage over flying," he says.
So if High Speed 2 is greener, quicker, if it solves overcrowding on the network, and if there is public appetite for such a service, which growth in Eurostar travel – 21% since the opening of St Pancras - would suggest, then why not just get on with it?
"We need a political champion to drive this through," says McCarthy.
"Lessons from High Speed 1 show High Speed rail can be built in the UK – this is obvious, but it is the overriding legacy. We learned that without a political champion – for High Speed 1 we had first Michael Heseltine and subsequently John Prescott – the project might not have happened."
While the government dances neatly around the subject of high speed – Ruth Kelly generally indicating she is in favour, but never quite giving it the push it needs to start – the Conservatives are far more keen.
A champion seems to be waiting in the wings. Shadow transport secretary Theresa Villiers has indicated in an exclusive interview with NCE, to be published next week, that High Speed 2 will be part of Tories' general election manifesto.
"The current government seems to be brain dead, and we are really just waiting for someone to switch-off the machine," says Imperial College professor of rail Rod Smith.
"It seems to me that we have to appeal to the Conservatives, who are very keen on these plans," he says.
"Imagine double the number of people at Liverpool Street. What do we do when this arises?”
Richard Eccles, Network Rail
"Key issues with such a transport project will be a 10-year lead in time, so if the planning started today, the bulldozers would not move in until 2018"
Chris Green, former Railway Forum chairman
Forecast increase in passengers wanting to use trains by 2035
High speed journey time from London to Birmingham
Cost of a second high speed line to Birmingham