Adelaide's north-south transport corridor runs between Gawler and Old Noarlunga.

This stretch of road provides a series of strategic free-flowing road links to connect the rapidly expanding industrial and residential growth areas in the north and the south, providing new opportunities for economic development.

New road links

Once completed (subject to detailed planning and funding allocations), the 78 kilometre corridor will comprise four road links:

• Northern Expressway from Gawler to Port Wakefield Road (complete)
• A future Northern Connector from Port Wakefield Road to the Port River Expressway 
• South Road from Port River Expressway to the Southern Expressway  
• Southern Expressway from Darlington to Old Noarlunga.

South Road priorities

A non-stop South Road is an integral component of the north-south corridor and a program to eliminate the worst bottlenecks is already well underway.

Following are the priorities for South Road:

ANZAC Highway intersection

In March 2009 traffic began using the brand new South Road / ANZAC Highway Underpass, the ‘Gallipoli Underpass’ for the first time.

The construction of the $117.9 million underpass at the intersection of South Road and ANZAC Highway was prioritised because of the often lengthy delays experienced by motorists.

South Road Superway

The next priority is to address the delays to traffic and improve the accessibility for heavy freight vehicles along the northern end of South Road.

The State Government has committed $432 million over five years, which will be matched by Australian Government funding, to build the South Road Superway.

The South Road Superway will create a non-stop link from Regency Road to the Port River Expressway.

Darlington

The third priority on South Road is at Darlington. The integrated Darlington Transport Study is investigating upgrades to key road and rail infrastructure in the area. These upgrades include:

• grade separation of South and Sturt Road 
• extending the Tonsley rail line and constructing a public transport interchange.

Southern Expressway

The Darlington Transport Study identified the advantages of bringing forward the long term plan to duplicate the Southern Expressway.

Construction of the duplication of the Southern Expressway will commence in late 2011 and will open to traffic in 2014.

Links with the north

In addition to these major upgrades on South Road, the 23 kilometre Northern Expressway, which links the Gawler Bypass with Port Wakefield Road, was constructed and is now open to traffic.

Planning for the Northern Connector is progressing with the Project's impact report released in July 2011. Once complete, the Northern Connector will join the new Northern Expressway to the Port River Expressway and to South Road, making a fast and efficient rail, freight and commuter link to and from the northern region.

The Northern Connector is listed as a priority pipeline project by Infrastructure Australia – the body responsible for advising the Federal Government on Australia's current and future infrastructure needs.

Future priorities

The State Government has commenced a detailed planning study that will build on previous work and determine the best solution for the section of South Road between the South Road Superway and Gallipoli Underpass.

Future investment in South Road requires careful planning to maximise the benefits of the investment while minimising the impact on adjacent business and residential communities.

The Australian Government has also recognised the importance of a north-south road corridor to South Australia and has committed $500 million through the Nation Building program to partner the State Government in development of this corridor.