Project overview

before and after

Duplication of the Southern Expressway will be constructed on the western side of the existing roadway and will give northbound traffic:

  • two lanes from Old Noarlunga to Reynella and
  • four lanes from Reynella to Bedford Park.

The existing carriageway will be used by southbound traffic with:

  • three lanes from Bedford Park to Reynella and
  • two lanes from Reynella to Old Noarlunga.


The design and construction works are being undertaken by a Joint Venture involving Baulderstone and Abigroup. The work is expected to take up to two years to complete.

In addition to a new carriageway along the length of the existing roadway, the project will include:

  • Extension of road bridges over the existing expressway
  • Construction of new bridges for a duplicated carriageway over Marion, Sherriffs and Lander Roads.
  • A new shared use recreational path on the western side of the expressway – providing an alternative environment to the existing veloway and shared path on the eastern side.
  • Modification of all existing interchanges to create new on and off ramps for the two-way expressway including:

    - Main South Road, Darlington (signalised junction)
    - Marion Road, Sturt
    - Panalatinga Road / Main South Road, Reynella
    - Sherriffs Road, Reynella
    - Beach Road, Noarlunga
    - Main South Road, Old Noarlunga (signalised junction)

The benefits of a duplicated Southern Expressway are: 

  • greater travel efficiency and better access for commercial traffic to industrial areas and facilities in Adelaide’s south 
  • improved access for people living in the Adelaide’s south to employment, education, recreation and community facilities both in the south and the wider metropolitan area 
  • reduced travel times and ease of journey to tourist locations along the Fleurieu Peninsula 
  • two-way travel 24 hours a day, seven days a week, the length of the Southern Expressway 
  • support for southern region economic development 
  • improved road safety for commuters 
  • improved emergency service access thanks to simultaneous north and southbound travel on the Southern Expressway. 

The project brochure (1.4 MB) provides a good summary of the project and details of the construction and design works, which are currently underway.

Follow the links under Project Overview on the left-hand side for more detailed information about the project.

Further project information can also be found in the: 

  • Project Impact Report, May 2011, which presents the need for the duplication, the initial concept and potential traffic, economic, social and environmental effects.
  • The Supplement Report discusses the further investigation into the project design following the release of the Project Impact Report.  It also responds to the submissions received from members of the public, community groups, local government and state government agencies.