Infrastructure expert Sir Rod Eddington has called for maximum transparency to allow the public to make up their own minds about major transport projects such as Melbourne's east-west link.
Sir Rod said he hoped to reach a point where governments are prepared to release detailed costings to allow independent scrutiny of major projects, saying his 2009 study examining the need for a new link had included 800 pages of analysis.
"I think transparency is invariably a good thing and I hope we will get to that point soon," he told a transport reform network lunch on Tuesday.
The state government is refusing to release an analysis of the costs and benefits or detailed traffic predictions for the 5.5-kilometre road link, suggesting it could jeopardise sensitive commercial negotiations.
It has instead published a "short form" brochure asserting the road, expected to cost between $6 billion and $8 billion, will generate $1.40 benefits for every $1 invested.
Opposition Leader Tony Abbott has warned there will be no money for commuter rail projects if he wins Saturday's election, saying the Commonwealth should "stick to its knitting" and fund road projects.
Asked about the comments, Sir Rod said he was keen to avoid a road versus rail debate, arguing a mix between the two modes would be vitally important to ensure people and freight continued to move efficiently.
"The premiers who are closest to the issues in their own particular state will decide what projects they wish to champion and which projects they don't, and then it is up to the federal government to decide where it does or doesn't want to provide financial support to those projects," he said.
"That's what elected governments do. I'm sure in my own mind that the states will take a broad, modally agnostic view of projects and will decide what their priorities are.
"But if they want to go to the federal government and get federal support for these projects then they will need to be mindful of which projects are and are not likely to be supported by the prime minister of the day."
Premier Denis Napthine has argued his government is still more transparent than the previous Labor government about the release of information on major projects.