Cabinet confidentiality ensures that we do not know how Tony Abbott voted when the Coalition frontbench met in 2000 to consider a proposal to finance part of the cost of the Alice Springs to Darwin railway link.
The so-called ''Steely Snowy'' scheme was a pet project of then prime minister John Howard and, after cabinet approved a $165 million contribution towards the $1.2 billion project, Asia Pacific Transport Consortium was chosen to lay the railway under a "build, own, operate and transfer back'' arrangement.
Although independent studies showed the completion of the Adelaide to Darwin railway would be economically viable, it has been anything but, and in 2010 the debt-plagued owner was sold to a US company for $334 million.
Any possibility that Mr Abbott might embrace a Steely Snowy scheme of his own at some point in a future Liberal-National Party government receded on Monday when he said the Coalition would focus on road projects, which could be started immediately and would deliver "better outcomes tomorrow, rather than in 40 years' time''. The first stage of a high-speed railway link between Sydney and Melbourne via Canberra (to which Prime Minister Kevin Rudd pledged $52 million on Monday for planning work) will be operational in 22 years, not 40. Nonetheless, two decades is an aeon in Australian political terms.
The high-speed rail advisory group says the cost would be $23 billion in current dollar terms. Mr Rudd's characterisation of this as cheaper than the opposition's paid parental leave scheme was pure politics but well made. When the cost of the second-stage Sydney to Brisbane line is added in, however, construction costs rise to an eye-watering $114 billion.
Transport Minister Anthony Albanese nonetheless believes that the economic benefit of a high-speed railway "stacks up'', and that it would created about 10,000 jobs in the construction phase. As the Alice Springs-Darwin debacle illustrates, all such claims need to be taken under advisement. And what of the economics of operation?
The passenger and freight catchment area for an east-coast high-speed rail link would dwarf that of the Northern Territory and South Australia but it is far from clear that it would provide the critical mass to justify Mr Albanese's confident predictions. Only by offering fares and freight deals similar to the airlines' and trucking companies' would a high-speed train be capable of attracting custom - and that would require significant, recurrent subsidies.
Even in compact and populous Taiwan, the economics of a high-speed railway have proved problematic. Pitching fares at the same level as airlines may have lured business travellers but people who are used to driving on Taiwan's well-maintained road network saw little reason to make the switch. The tendency would be for private motorists do the same in Australia.
So long as the alternatives of driving and flying are inexpensive, reliable and quick, the economics of operating a high-speed railway would be nigh on impossible. There is, of course, no guarantee this will continue to be the case, which is the biggest single argument for persevering with a high-speed rail link. A steep escalation in the price of oil would be a potential game-changer, although there is a likelihood that a switch to some other automotive fuel (such as compressed natural gas) would keep many travellers on the roads and away from railway stations.
The appeal of high-speed rail travel might well be improved if government stopped, in effect, subsidising road travel. Motorists bear only a fraction of the billions of dollars spent by governments on building, improving and maintaining interstate highways and, as Australia's population rises, these roads are going to become increasingly crowded and problematic. Politicians like Mr Abbott are right to be sceptical about claims made of a high-speed rail link, but to continue to subordinate rail to roads would be to put Australia's future transport efficiency at risk.