In this there is ''moral hazard'', because those who will make money from the road are not those who will invest in it or use it. Knowing that their employer and cash cow has committed itself to the construction, there is a strong incentive for consultants to invent reasons for the project from which they can walk away when the financial architecture they have created collapses like a house of cards. Private investors are surprisingly gullible when it comes to investing in road schemes. The Sydney Cross City Tunnel, coincidentally another east-west link, is a case in point. There are distinct similarities between the tunnels. The history of the Cross City Tunnel should be kept firmly in mind by the federal government, its agency Infrastructure Australia and any private investment funds that, if the state Treasurer is to be believed, are clamouring to put money into the venture. The Cross City Tunnel, initiated by the NSW Road Traffic Authority, began with the idea of bypassing a bottleneck and making the surface streets more available for north-south traffic crossing the proposed tunnel. The plan included changes to city streets and nearby residential streets to make life safer for pedestrians. According to the cost-benefit analysis, most of the benefits of the tunnel were to accrue to the general public in the form of pedestrians and residents of nearby neighbourhoods.

As in Victoria, but more so, the NSW Treasury did not want to pay for the tunnel. So the government insisted a fee of $100 million be added to the business case for the tunnel to cover the state's expenses. This ensured there would be no loss to taxpayers if the project failed, but it also added one-sixth of the project cost and increased the risk for private investors. If the project were to be built at all, it had to be funded by tolls. This meant its business case had to be based on unrealistically high traffic estimates, which grew as project negotiations progressed. The final business case was based on traffic volumes of 90,000 vehicles a day. It is perfectly clear this flow could never have been achieved. That many vehicles (subject to morning and evening peak flows) could simply never have been accommodated in a two-lane tunnel with an 80km/h speed limit and single-direction peak load, no matter what the demand. Moreover, the predicted demand for the total number of people estimated to wish to move east-west in 2006 was only 77,000. As soon as the tunnel opened, criticism began. Traffic numbers were (unsurprisingly) much lower than forecast. Tolls were considered exorbitant given the distance to be travelled. The government was accused of aiding the company that built and owned the tunnel by allowing the tunnel operators to make the contracted changes to surface streets. The original owners, including several Australian pension funds, were declared insolvent in 2006, within two years of the project opening. Changes to the surface streets were reversed, the benefits to surface users (pedestrians and residents) abandoned. The project resulted in increased road space for toll payers and little else.

The similarities between Sydney's Cross City Tunnel and Melbourne's east-west link are significant. Well-paid consultants will be appointed to generate a business case that includes sufficient tunnel users to pay the tolls - whether or not they can reasonably be expected to emerge. Much of the $294 million allocated to planning for the tunnel over the next two years will be paid to consultants. The Victorian government wants to be seen to be building something good for the broader community but not to pay for it. To promote the idea that the tunnel is not simply about facilitating access to the city for drivers and to limit the destruction to Royal Park from new exit and entrance points, unrealistic requirements are being written into the specifications. There will apparently be no off ramps into the city, which will make the tunnel less attractive for the large majority of Eastern Freeway users. It would be surprising if this requirement makes it into the final project. Similar promises were originally made for CityLink, but abandoned when the traffic numbers simply didn't stack up. Of course, the other possibility is that the tunnel truly isn't about drivers entering the city, but instead about spreading the load of B-double trucks to the relatively truck-free eastern suburbs - so they, too, can enjoy the dubious benefits of accepting the transport costs associated with just-in-time logistics. The east-west tunnel is a road to a loss. The only question is who will lose and by how much: the public through taxes levied by the state and Commonwealth, the Eastern Freeway motorists through tolls, or the private investors.

Sophie Sturup and Nicholas Low researched CityLink, the Sydney Cross City Tunnel and the Perth Southern Railway for the OMEGA project. OMEGA is a 10-nation study of transport mega-projects led by Professor Harry Dimitriou of University College London.