An ambitious plan set by Prime Minister Tony Abbott to turn Adelaide's South Road into a non-stop north-south corridor in the next 10 years will cost almost $7 billion, a planning study provided to ABC News shows.

The $8.5 million strategy, prepared by the South Australian Government, shows 10 different road projects need to be completed at a total cost of $6.8 billion in today's money.

That does not include two projects that have already been funded: the Darlington Road upgrade, and River Torrens to Torrens Road upgrade.

The costs include building elevated and lowered sections of roadway, and acquiring land, homes and businesses, which will cost more than $1 billion alone.

The 161-page planning study highlights the section of South Road from Anzac Highway to Torrensville as the biggest priority, but also the most expensive.

An upgrade of that section would cost $2.3 billion, and would include short tunnels under James Congdon Drive, Sir Donald Bradman Drive and Henley Beach Road.

In October 2013 Mr Abbott pledged to upgrade South Road within a decade.

"Let's try to get the whole North-South Road Corridor upgraded within a decade," Mr Abbott said.

"Let's face it, we've been talking about it since 1968."

State Treasurer Tom Koutsantonis said the 10-year pledge was unlikely to be met because no additional funds were put forward in the 2015 federal budget.

"We've based our strategy on an 80:20 funding split," Mr Koutsantonis said.

"Minister Briggs has got no new money in this budget for it. We can't acquire any new properties.

"The project has basically blown by a year."

State Government to blame for delay: Briggs

The planning study was paid for by the Federal Government, but delivered by the State Government ahead of an agreed schedule.

But Federal MP Jamie Briggs has blamed the State Government for stalling the project, saying the planning study does not provide sufficient detail.

"This is just a plan. This is not a project proposal and there is no proposal from the State Government on what their priority is yet," Mr Briggs said.

Mr Briggs said the planning study did not make a recommendation on a construction program and did not include any economic analysis of corridor projects.

He said he would now ask Infrastructure Australia to decide which South Road projects should be built first.

The north-south corridor extends 78 kilometres between Gawler north of Adelaide and Old Noarlunga to the south.

It traverses rural and urban land and South Road is lined with businesses and homes throughout metropolitan Adelaide.

Some 44 kilometres of non-stop motorway has already been completed, with a further 34km needed to be developed to complete the full corridor.

The timely acquisition of land is considered critical for the project's timeframe, with the document acknowledging that "compulsory acquisition is a highly emotive outcome".

The non-stop motorway proposal is designed to cater for high speed free-flowing traffic, but would also include a "surface arterial" South Road, that would generally run parallel to the motorway for local traffic.

SA Government 'most difficult in Australia'

Federal Treasurer Joe Hockey told 891 ABC Adelaide this morning that he had difficulty negotiating with the SA Government, and called it "the most difficult government to work with in Australia".

Treasurer Joe Hockey discusses the north-south corridor in 891 ABC Adelaide studio with breakfast co-host David Bevan. ( 891 ABC Adelaide: Brett Williamson )

"Unfortunately, they're keen on playing politics all the time, rather than getting on with the task of building things," he said.

"If you want it done quickly, the best thing to do is to stop playing politics."

Mr Hockey said the Government had received a draft plan of the road strategy in December, but it did not include any proposals.

He said it responded with feedback and further added that tolls should be considered as a funding mechanism to help pay for the corridor.

Mr Koutsantonis said if the Federal Government wanted the project completed within 10 years, then it needed to allocate funding immediately.

"This plan has been with the Federal Government since December last year yet received no support in the federal budget," he said.

He said the Federal Government "always had a partner in South Australia if they were willing to fund productive road infrastructure".

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