New tunnels, extra bridges across the river, an inner-city subway and new train lines are being proposed in a long-awaited transport plan for the Perth and Peel regions.

It includes a proposal for an East-West City Link to ease congestion on existing Swan River crossings east of the CBD, including the Graham Farmer Freeway and the Causeway.

The link is one of a vast number of projects in the plan, which maps out what transport infrastructure could be needed as WA moves to an expected population of 3.5 million by 2050.

The East-West Link would consist of two new connections, one which would involve a riverside bridge or tunnel connecting Canning Highway at Berwick Street to Riverside Drive at Plain Street east of the Perth CBD.

The second would be an East-West tunnel which connected Riverside Drive west of Plain Street with the Narrows Bridge interchange and Mounts Bay Road.

It was expected the East-West Tunnel section would carry about 50,000 vehicles a day and significantly reduce volumes of traffic on Riverside Drive.

It is understood the plan floats the idea of closing Riverside Drive in the longer term to enable better activation of the Perth waterfront.

The idea is the link would keep traffic travelling through, not to, the CBD, thereby relieving pressure on city roads and the Graham Farmer Freeway.

Push to get more commuters out of cars

The plan, known as Transport@3.5 million, provides a long-term vision to guide development of WA's transport network for Perth and Peel, with an expected 800,000 new homes required over the next 35 to 40 years.

Transport planners believe that would nearly double the number of trips made every day in and around Perth, leading to more than 12 million trips a day.

The ABC understands the plan aims to increase public transport use to 11 per cent of all-day trips, including about 65 per cent of peak period trips to the CBD.

Dean Nalder says the plan examines all transport modes. ( ABC News: Andrew O'Connor )

Transport planners also hoped greater public transport use would increase cycling and walking to 18 per cent of all-day trips, and reduce car driver trips to 50 per cent of all-day trips and to 29 per cent of peak-period trips to the CBD.

The plan estimated the cost of congestion in Perth in 2015 was $2 billion per year, and it is understood the plan predicts that, without change, that figure would more than double to between $4 and $5.7 billion a year by 2030.

The document is also expected to include a long-term proposal for a separate underground inner-city subway system to provide high-capacity, high-frequency, short-distance connections between central Perth, West Perth, Leederville, East Perth, Northbridge and other inner city centres.

The ABC has been told the plan would also propose a new suburban rail line to service Morley and East Wanneroo, connecting to the Joondalup line to service the far northern suburbs.

Referred to as the East Wanneroo Rail Link, the project would be delivered in three stages.

The first would be from the Perth CBD, via a tunnel to Morley, to a station in Beechboro.

The second stage would connect to the Joondalup line, north of Clarkson Station, and the third would see a rail spur built from Marshall Road in Beechboro to Ellenbrook.

The ABC has been told the plan also flags a number of routes which would have to be serviced by either light rail or a bus rapid transit system by the time Perth's population hits 2.7 million. These include:

A connection between Ellenbrook to Bassendean station, Midland and the new East Wanneroo Rail Link

A connection between Ellenbrook to Bassendean station, Midland and the new East Wanneroo Rail Link A connection from Glendalough Station to Scarborough Beach, via Scarborough Beach Road

A connection from Glendalough Station to Scarborough Beach, via Scarborough Beach Road A route between major centres including UWA QEII Medical Centre through the Perth CBD area to Curtin University in Bentley

Funding not a part of transport plan

Heading into Cabinet on Monday, Transport Minister Dean Nalder said the plan was before Cabinet and he hoped to release it for consultation by mid-July.

He confirmed the plan did not look at funding but rather what the city would look like and how West Australians would commute into the future.

"It's looking at all modes of transport across Perth, but looking a long way into the future," he said.

Rita Saffioti remains sceptical about the transport plan. ( ABC News: Andrew O'Connor )

"It can't be just about roads. It has to be about public transport. It looks at all modes."

Opposition transport spokeswoman Rita Saffioti said the Government had been trying to work on a document to plan for WA's transport needs for eight years but had failed to deliver on basics like the Max Light Rail project it promised at the 2013 state election.

She said without clear project priorities and accurate costings, the plan would be little more than a collection of grand ideas.

"This document will be full of nice pictures, some computer animations I suspect, but you can't trust the Liberals of public transport," she said.

"We are into believable and deliverable public transport solutions for Perth, not some concepts, which should have actually been delivered by now and not just creating documents."