A raft of South Australian road projects are on the chopping block after the federal government scrapped its commitment to fund the upgrades, but the state's marquee North-South Corridor tunnel has been spared the axe.
Two major congestion-busting investments in the Adelaide Hills, the $202 million Truro bypass project and the $250 million Hahndorf township improvements and access upgrade, had their funding scrapped on Thursday.
Funding for the Main South Rd upgrade between Myponga and Cape Jervis, the Old Belair Rd upgrade at Mitcham and the upgrade of the Onkaparinga Valley Rd and Tiers Rd intersection at Nairne has also been cut.
A federal government review of the nation's infrastructure pipeline found the projects "do not demonstrate merit, lack any national strategic rationale, and do not meet the Australian government's national investment priorities".
"In many cases these projects are also at high risk of further cost pressures and/or delays," the report said.
South Australia Infrastructure Minister Tom Koutsantonis said the state did not have the money to forge ahead with the five unfunded projects, with $440 million lost in Commonwealth lost.
"That would be a dramatic impact on the South Australian budget and we've got our priorities to try and make sure we can deliver on our health commitments, on our education commitments and our infrastructure commitments," he told reporters.
"These are the Commonwealth government's cuts.
"These are not our decision."
Mr Koutsantonis said the Truro bypass was vital for improving road safety and freight movements and pledged to push the federal government to get it over the line in the long term.
He said South Australian taxpayers should feel aggrieved with the federal government's decision, given $50 million had already been spent by the state on projects which will no longer be going ahead.
The Commonwealth will sink an extra $2.7 billion into the North-South Corridor, the cost of which has blown out to more than $15 billion.
The project, which involves the construction of twin 10.5km tunnels from Torrens to Darlington, will continue to be funded on a 50:50 basis between the state and federal governments.
Another $361 million was set aside for eight projects lumped into a newly-established Princes Highway corridor.
Opposition Leader David Speirs welcomed the increased funding for the North-South Corridor, but said the cuts had a disproportionate impact on regional SA.
"This announcement is devastating for South Australia and proves Labor has completely turned its back on our region," he said.
"South Australians were told with both state and federal Labor in government Peter Malinauskas would stand up to his Canberra colleagues for the best interests of our state - but he's just waved the white flag."
A report released by the state's auditor-general on Tuesday found budget overruns and rising interest costs incurred by South Australia's infrastructure program threatened the government's fiscal capacity and ability to deliver services.