The Morrison and Marshall Governments have put $5.4 billion on the table towards completion of the final section of the North-South Corridor, between Darlington and the River Torrens.
Once complete, the 78-kilometre North-South Corridor will be the major non-stop route for north and south bound traffic, running between Gawler and Old Noarlunga.
The final 10.5-kilometre section will link the Darlington upgrade which is currently under construction to the recently-opened Torrens to Torrens project.
"The final section of the North-South Corridor will be the single biggest infrastructure project in South Australia's history," said Premier Marshall.
"The Liberal Government has always been committed to completing what is South Australia's number one infrastructure priority.
"This project will be the major route for freight and commuters traveling north and south and will slash travel times and boost economic productivity.
"Importantly, this project will underpin thousands of construction jobs for almost the next decade.
"We have already announced a record $11.3 billion investment in infrastructure in South Australia and this massive project underpins a strong pipeline of works for years to come."
Minister for Transport, Infrastructure and Local Government Stephan Knoll said the business case for this massive project was being fast tracked and was due in the middle of the year.
"The Marshall Government committed $5.5 million in our first State Budget to fast track the business case for this remaining section of the North-South Corridor," said Minister Knoll.
"Unfortunately, the previous State Labor administration failed to start this business case at all – Labor did absolutely zero work on this – zip, zilch.
"By contrast we're getting on with the job and we're fast tracking this business case which is a very significant and complex body of work.
"Through the business case process, we are assessing what will deliver the best outcome and if that is going to include one long tunnel, a number of smaller tunnels or at grade motorways.
"This final 10.5-kilometre section of the 78-kilometre North-South Corridor is set to cost more than the other 68 kilometres that has either been built or is currently under construction."
