The North-South Corridor is identified as one of Adelaide's most important transport corridors and will be the major route for north and southbound traffic, including freight vehicles, running between Gawler and Old Noarlunga.
The current roadway is not working effectively and will not be able to handle the projected number of vehicles that will need to use the road, or cater for the size of freight carriers wanting to travel along it.
In response, the federal and South Australian state governments are working collaboratively to expand the route by creating a dedicated non-stop North-South Corridor.
According to transport minister Stephan Knoll, business cases will be submitted to Infrastructure Australia for installing tunnels at the River Torrens to Anzac Highway and Anzac Highway to Darlington sections.
"One of the Liberal government's infrastructure priorities is completing the remaining sections of the North-South Corridor," Knoll told News Corp Australia.
"Unfortunately, these sections of the North-South Corridor could never begin because Labor were lazy and never did the work."
"The federal government has earmarked $1.2 billion of funding for remaining sections of the Corridor.
"We're now got a significant funding commitment from the federal government and we are moving quickly to get these projects off the ground as soon as possible."
A tender has been opened to investigate the tunnelling, and business cases will be submitted by the end of the year.