South Australia's peak transport industry lobby group has expressed major concerns with a Liberal proposal to build a freight-only airport east of Adelaide to link with new rail and road bypasses around the city.
Opposition Leader Steven Marshall says the new corridor would avoid the heavily populated areas of existing freight routes and is long overdue.
He has promised to spend $20 million to investigate full funding options for the project, which would cost billions of dollars, if the Liberals win the 2018 state election.
Safe, efficient and sustainable road freight infrastructure was central to unlocking the productive capacity of South Australian businesses and exporters, Mr Marshall said.
But Transport and Infrastructure Minister Stephen Mullighan said a similar proposal had already been examined and an independent report by a world-leading engineering firm found the costs would be far greater than any benefits offered.
The SA Freight Council similarly said a freight-only airport would not be sustainable while the rail bypass had been studied numerous times and proved unviable.
Council executive officer Evan Knapp said the billions of dollars would be better spent on completing the north-south road corridor through Adelaide and addressing the significant road maintenance backlog in SA.
“We are disappointed that the freight industry was not consulted on this plan prior to a public announcement,” he said.