The state government is considering an underground rail line from the Perth CBD to Morley and then eventually to Ellenbrook, Transport Minister Dean Nalder has confirmed.
The Minister, though not intending to go public with an announcement for some months, acknowledged in response to media questioning on Monday that the government had added heavy underground rail to the list of solutions being considered for the eastern suburbs.
The underground train would go past Edith Cowan University's Mt Lawley campus to Morley, probably to the Galleria shopping centre.
Eventually, it could be extended to Ellenbrook, though modelling suggested it would be "considerable" time before this extension was required.
The government promised before the 2013 election to build a MAX light rail system to Ellenbrook but deferred the project following the election. More recently talk has centred around the possibility of a rapid bus system.
Mr Nalder said the government was using $5 million remaining in the MAX 'account' to engage independent research into a subway and compare it to that already done on light bus and MAX.
He said work on the Forrestfield airport link, about to go to tender, had proved underground rail could be achieved with similar costs to above-ground.
This was all in the context of planning for public transport to cater for the Perth and Peel regions' population as they grew to a projected 2.7-2.9 million by 2031 and 3.5 million by 2050.
While not committing MAX to the dustbin with certainty, he said he had "challenged" whether it was the best solution.
"I can't commit one way or another but what I said yesterday is that for the capital costs on the capacity you get on light rail versus heavy rail, I do favour, slightly, that heavy rail option," Mr Nalder told Radio 6PR on Tuesday.
Mr Nalder hopes to take a proposal to cabinet early in the second quarter of 2016 and thereafter provide more information to the public.
He said it was possible the subway could cost a similar amount to the MAX system, priced at $2.5 billion.
Mr Nalder said he felt state governments had a history of doing things "just in time and retrofitting public transport to a sprawling city".
"We have sprawled north and south as a city and the pressure keeps coming to retrofit public transport out to those sprawling areas to be able to bring them in. If we are a city that is going to move towards 5 million people over the next 50 years, we need to create greater density around the activity centres.
"So major shopping centres, you are going to see increased urban development around those, and I think we need to provide better linkages around the CBD and around those activity centres to encourage that density ... as well as meet the growing demand around those other suburbs."
He wanted to deliver on projects, but also lay down foundations for longer term planning that took Perth out into the next few decades and this would be announced along with the decision on the subway.
"I want this well researched so there is a clear vision for this city," he said.
