Former WA Labor premier Carmen Lawrence has launched a scathing attack on the proposed Perth Freight Link, labelling the State Government "pig-headed" and the Environmental Protection Authority "weak".

Dr Lawrence is now a professor of psychology at the University of Western Australia, and rarely makes political comment.

The North Fremantle resident said the stage one Roe 8 component of the $1.6 billion Perth Freight Link was an "absolutely ridiculous idea" that was shelved by several previous governments for good reason.

"God knows why they've chosen to put it back on the agenda and to spend the best part of $2 billion on part of a road that in the end goes nowhere, it gets stuck at the Stirling Bridge ... It's wrong headed and pig-headed," she said.

The Barnett Government has committed to the completion of Roe 8 through the Beeliar Wetlands by extending the Roe Highway from Kwinana Freeway to Stock Road, with contracts expected to be awarded in the coming months.

The second stage, known as Roe 9, would link Roe Highway to the Fremantle Port by an as-yet undetermined route.

Dr Lawrence said the business case for the freight link project was incomplete and did not fully take into account social impacts.

"We don't know what these other effects will be let alone on the sense of human wellbeing and community, and big roads like that drive a wedge right between communities," Dr Lawrence said.

"People will be losing their houses, there will be increases in particulate pollution and we don't even the extent of that ... and for children it's a serious risk."

Dr Lawrence said alternatives should be considered.

"Partly because the Port of Fremantle isn't going to be the principal port in 10, 15 years' time, and secondly, rail is a far better option for most of that traffic, and there are smarter ways of planning cities than driving big freeways right through the middle of them," she said.

Concern over environmental values

Dr Lawrence condemned the Environmental Protection Authority (EPA) for its role in approving the freight link, and said the general approach to the project was part of a wider silencing of environmental concerns in WA.

"It (the EPA) appears to simply fall in line with the Government. There was a time when it was a more much vocal supporter of environmental values," she said.

"When people talk about the need to protect their places, whether it's Indigenous culture or for instance the suburbs that are affected by the Roe Highway, they are told they are being nimbys or they are being selfish.

"We are losing species at such an alarming rate, it should be headlines everyday frankly. We've got Marri trees dying, peppermint trees, there are all sorts of impacts from sources we are not even clear about on our South West forests.

"We can be better custodians of this land instead of seeing it as ripe for rip and tear."

Dr Lawrence's criticisms come ahead of her keynote speech, titled 'Bleeding the Land Dry', at the Festival of Disrupted Ideas at WA's State Library tomorrow.

A spokesman for the Transport Minister Dean Nalder said the preferred concept design for Roe 8 met strict environmental conditions and regulations determined by the EPA.

"It would be built on land partly cleared for overhead power lines in order to minimise the environmental footprint, and had been subject to comprehensive environmental studies and a public participation program," the spokesman said in a statement.

The statement also highlighted environmental work to be done as part of the project, including a wetland restoration program, a top-down construction approach, the use of wetlands bridges and the purchase of more than 400 hectares of native vegetation as an environmental offset.