Labor tram promise 'key' to SA's future

Adelaide's proposed new tram network is essential for South Australia's infrastructure transformation, Premier Jay Weatherill says.

Federal Labor leader Bill Shorten on Tuesday pledged $500 million to kick start the AdeLINK project should he win government on July 2.

"This is an exciting announcement which addresses two of our federal election priorities - to grow our public transport network and to support our sovereign steel industry," Mr Weatherill said.

Under AdeLINK, trams would run from the CBD throughout the suburbs, not just on a single track to Glenelg.

Mr Shorten, who brought his election campaign to Adelaide on Tuesday, said Labor's promise of pre-construction funds would help create 2000 jobs and fast-track an Infrastructure Australia assessment process as the state government prepared its business case.

"We think a new tram project, six new trams, is just exactly what Adelaide needs in dealing with congestion," he told 5AA radio.

"The cost of congestion is going to quadruple in Adelaide in coming years from $1 billion to $4 billion.

"When you look at the pros and cons, this AdeLINK project is exactly what the doctor ordered for Adelaide."

But Minister for Major Projects Paul Fletcher questioned whether SA could afford to fund its part of the tram expansion.

"What we've just seen from Labor is a rushed commitment to the AdeLINK project," he said.

"There's no business case that has been prepared for this yet by the South Australian government."

The total cost of the tram project has been estimated at about $3 billion and SA will likely look to the Commonwealth for a large slice of that.

But it also hopes private investment may contribute to some of the cost along with local government.