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Most car makers offer prospective buyers different models of a new vehicle. Buyers who are on a tight budget can go with a basic model with no frills. Well-heeled buyers can choose a top-of-the-line option with all the creature comforts. As in most things, what you get depends entirely on how much you are prepared to spend.

The same applies to infrastructure. The consultants working on a federal government-funded feasibility study into a high-speed rail network from Brisbane to Melbourne via Sydney and Canberra are believed to be canvassing three options for terminals in the capital - one in the heart of Civic, a station further north at Mitchell, or a terminus at the airport.

A station in central Canberra is clearly the luxury option. The consultants suggest a spur line from Yass could travel into the ACT to the east of Mount Majura, through a tunnel under Mount Ainslie, and down Ainslie Avenue before terminating near the Canberra Centre. Just where, however, is not certain.

Having declined in popularity in the post-war years, rail is now viewed as one of the smartest and most environmentally friendly of all the current and future public transport options. Many people would take pride in a high-speed train terminating at Civic, but stations at Mitchell or the airport would be attractive alternatives.

Unlike Civic, space would not be an issue at Mitchell, and a station at the airport would create a transport hub allowing passengers to quickly and easily transfer between trains and planes, making the city more attractive to international travellers . Add a light rail service connecting the Territory's major town centres and a picture begins to emerge of an integrated transport system that befits a city of Canberra's importance.

As enticing as it might be, talk of stations, and tunnels through Mount Ainslie, will appear to many to be a case of putting the cart before the horse. After all, a network in Australia remains nothing more than a vision at this point - if one explored in several costly feasibility studies. Such studies have a habit of gathering dust in the archives, and cynics would argue that the latest, initiated by former prime minister Kevin Rudd, is likely to go the same way.

It's certainly the case that rail advocates such as former Coalition deputy prime minister Tim Fischer have never been able to mount compelling economic arguments for a fast train network in Australia, let alone one operated by the private sector.

One certainly could have been made for Taiwan, a country roughly half the size of Tasmania with about the same population as Australia, in the late 1990s. A private company, Taiwan High Speed Rail Corporation, went ahead and built a line between the country's two largest cities, opening for business in 2007. Despite setting ticket prices below existing airline fares (but higher than rail and bus fares), the corporation quickly ran into financial difficulties and had to be bailed out by the central government two years later.

Like all the world's high-speed trains, an Australian network would require large government operating subsidies, probably for its life. In theory at least, Labor might be counted on to be a willing underwriter. With its ideological opposition to big government and any direct involvement in infrastructure provision, the Liberal Party's support for a high-speed train would be more grudging.

Estimates of the cost of connecting the largest cities on the east coast vary between $61 billion and $108 billion. Given that the cost of building Taiwan's 345-kilometre line - over more challenging terrain - totalled $18 billion, a figure of $110 billion appears neither conservative nor over-inflated. On the other side of the ledger, companies with an economic interest in being located on the line (such as Canberra Airport) could doubtless contribute to the cost of building stations. Increased economic activity along the corridor would also be a benefit. Among the many arguments in favour of high-speed rail, reductions in road traffic and improvements in safety are not insignificant, either.

In a sparsely populated country such as Australia, high-speed rail does not immediately present as a viable transport solution. But it has considerable appeal as an effective way to encourage decentralisation - and to reduce our dependence on carbon-intensive road transport. As our cities become more crowded, and as the threat of global warming intensifies, the environmental and economic attractions of high-speed train travel will become increasingly difficult to ignore.