The South Australian Government's lobbying efforts for federal transport funding have switched focus onto tram and rail projects, and away from roads, following the departure of Tony Abbott from the prime ministership.

Acting Premier John Rau said the State Government would make new submissions to Infrastructure Australia to significantly expand Adelaide's tram network and complete the electrification of the Gawler railway line.

"Mr Abbott as prime minister wasn't very interested in rail," he said.

"The fact that we now appear to have a different attitude in Canberra is very welcome and that means we shift our emphasis now from road projects that we've got sitting there, over to rail projects."

Mr Rau said he had been encouraged by comments from Prime Minister Malcolm Turnbull and recently appointed Minister for Cities and the Built Environment, Jamie Briggs.

The tram network expansion plan was unveiled in 2013 and would see new lines branching out to destinations including Semaphore, Blair Athol, Mitcham, Magill and the airport.

But Mr Rau said he was happy to consider alternatives.

"If the Commonwealth's happy to talk about going up O'Connell Street, so are we," he said.

The full electrification of the Gawler rail line was announced in 2008 but later delayed for budgetary reasons.

"We're talking in the hundreds of millions of dollars. It's a significant investment," Mr Rau said.

"We have to sit down with [the Federal Government] and find out what they've got in terms of their budget."