Thousands of pages of reports on the environmental effects of the Andrews government's West Gate Tunnel project have been released.

Roads Minister Luke Donnellan announced the release of the Environment Effects Statement in Yarraville on Monday morning.

The West Gate Tunnel, originally known as the Western Distributor, is a proposed 5km tollway to link the West Gate Freeway at Yarraville with CityLink at Docklands.

The $5.5 billion tollway will have at least two city off-ramps into West and North Melbourne.

The public will have 30 working days to respond to the expected effect of the massive road project. The reports to be released by Transurban and the government on Monday will contain an estimated 10,000 pages of information.

Two custom-made tunnel boring machines will be used to build the tunnel, shifting more than 1.5 million cubic metres of rock and soil – some of it badly contaminated.

The government has also committed to planting more than 17,000 trees as part of the project, including 4000 mature trees, replacing those that need to be removed at a ratio of more than three to one.

Mr Donnellan said the new tollway would deliver time savings for motorists from Ballarat, Geelong, Lara and Point Cook "of at least 20 minutes".

He said the environmental effects statement was the first time there had been a "human impact study" done for such a project, and it had found there would be "no noticeable changes to human health".

The planned location for ventilation stacks from the tollway tunnel had been moved as a result of this work, he said.

Asked why the community was only being given 30 working days to respond to the design of the project, Mr Donnellan said there had been two years of extensive consultation already.

"No-one would suggest we have hidden this project under a bushel. We have been out there for many years consulting with the community ensuring we get it right."

The state government is concerned that it will have to fight for the support of either the Greens or the Coalition to get the financial arrangements for the West Gate Tunnel through Parliament.

The project is being done by Transurban. The government will hand Transurban an extension of tolls on CityLink for at least a decade, in return for the toll road operator building and partly financing the new tollway.

An analysis last year by The Age and transport actuary Ian Bell, for the then-proposed 12-year extension of the CityLink tolls to help pay for the West Gate Tunnel, found it would generate $20 billion to $30 billion in extra toll revenue for Transurban.

Greens MP Colleen Hartland said it was not acceptable that community groups would only get 30 working days to respond to the Environment Effects Statement.

Transurban and the government had taken almost a year to write the reports, she said, but residents, community groups and councils would only get weeks to respond.

"It's disgusting. It totally eliminates community consultation. If they are genuine about community consultation, you give people at least 60 days to do this."

Ms Hartland said that the problem of adequately responding to the environment report the was shown by issues even councils had in getting their responses together.

"Maribyrnong Council's biggest problem has been finding traffic consultants [to write a report responding to the road] because they're all working for Transurban," she said.

Opposition roads spokesman Ryan Smith said that the government would struggle to get support for the project through Parliament unless it was more transparent about the financial deal being done with Transurban.

"Until we see financial statements for this project, we're not supporting it," Mr Smith said.

"My personal position is that Transurban is gouging motorists and Daniel Andrews has backed himself into a corner – it's the worst negotiating position possible for taxpayers," he said.