A $2 billion infrastructure package has been promised as a centrepiece of Labor's re-election hopes for the March 17 election in South Australia.

Premier Jay Weatherill told a launch function at the Adelaide Convention Centre a fifth-term Labor government would remove seven level crossings, further extend tram lines across Adelaide and build a bulk commodity port on Spencer Gulf.

Level crossings which would go: Marion and Cross roads, Plympton Park

Marion and Cross roads, Plympton Park Goodwood Road, Goodwood

Goodwood Road, Goodwood Cross Road, Westbourne Park

Cross Road, Westbourne Park Brighton Road, Hove

Brighton Road, Hove Trimmer Parade/Tapleys Hill Road, Seaton

Trimmer Parade/Tapleys Hill Road, Seaton Park Terrace, Salisbury

Park Terrace, Salisbury Torrens Road, Ovingham

"This package, which guarantees a continuous pipeline of work for the construction industry, will create 1,700 jobs every year over the coming four years and build on Labor's record of delivering world-class infrastructure," he said.

"[We will remove] seven of the most dangerous and congested train and tram level crossings across Adelaide, expand our city tram network and establish a multi-use bulk commodity port in the Spencer Gulf."

Labor said its level crossing upgrades would be entirely funded from state budgets, not dependant on federal money.

The South Australian Freight Council said a new deep water port would offer significant benefits for the mining and farm sectors.

Council executive officer Evan Knapp said both sectors had long been urging improvements to benefit the Eyre Peninsula-Upper Spencer Gulf region.

"There are several mining ventures in the region that could potentially benefit from a new deep water export facility now," he said.

"[There are] more large projects in the development pipeline — like Iron Road's Central Eyre iron project and OZ Minerals' Carrapateena copper project."

Mr Knapp said a deep water facility would allow massive ships into the region.

Opposition Leader Steven Marshall said Labor had made numerous deep port promises over the years.

"I think this is Labor going back to the old campaign ideas drawer," he said.

Liberals' first 100 days pledge

At a news conference, Mr Marshall has outlined how a Liberal government would spend its first 100 days in office.

He said efforts to lower payroll tax, dissolve the TAFE SA board and ban fracking in the south-east of South Australia would start in his first week as premier.

Steven Marshall, flanked by colleagues, announced plans for a first 100 days in government. ( ABC News: Trent Murphy )

"What you're going to get from the Liberal Party is not talk, but action — action straight away, day one of a Liberal government," he said.

Mr Marshall expressed confidence all the members of his current shadow cabinet would be re-elected and serve as ministers in their current portfolio areas.

"We will be not only be creating charter letters for each of our ministers, identifying what they need to be delivering on, but we're going to be publishing these to the public," he said.

"People need to see a government that is going to be held accountable and responsible for real action for the people of South Australia."

He said the public and the media could hold a Liberal government to its plan.

First 100 days priorities outlined by Mr Marshall included:

Preparing legislation to extend shop trading hours and cap council rates

Preparing legislation to extend shop trading hours and cap council rates Starting a $100 million battery subsidy scheme to benefit 40,000 homes

Starting a $100 million battery subsidy scheme to benefit 40,000 homes Announcing parliamentary sitting dates and working on the next state budget

Announcing parliamentary sitting dates and working on the next state budget Preparing to set up a state productivity commission

Preparing to set up a state productivity commission Rezoning the Repatriation Hospital Adelaide site as a health precinct

Emergency levy relief promised

Nick Xenophon said if SA Best achieved the balance of power beyond the election, active emergency services volunteers would receive a full rebate on the emergency services levy (ESL) they paid.

He said for a volunteer and family with a house valued at $430,000, the rebate would achieve a saving of about $270 annually.

Mr Marshall was sceptical of his political opponent's move.

"Again it's thought-bubble politics from Nick Xenophon. He hasn't spoken to the volunteers, they're not actually calling for this," he said.

Mr Weatherill was also dismissive.

"It's up to Nick to explain these things and how he's going to pay for them," he said.

SA Best also promised to match a Liberal pledge to reduce annual ESL bills for the wider community.