The Australian Government has shortlisted two bidders to tender for the construction of the Darlington Upgrade on the North South Corridor.

The two bidders are Lend Lease and Gateway South, a consortium consisting of a joint venture between Fulton Hogan Construction and Laing O’Rourke.

The Australian Government is contributing 80% of the cost of the A$620m ($461m) Darlington Upgrade project with the remaining 20% being contributed by the South Australian Government.

The government has identified the two bidders by conducting expressions of interest earlier this year.

"The Darlington upgrade will deliver significant travel time savings for commuters travelling through this section of South Road."

Claimed to be one of the largest road investments in South Australia, the project will see the upgrade of the 2.3km section of Main South Road between the Southern Expressway and Ayliffes Road.

During the construction phase, the project is set to create 370 jobs a year and efforts will be put in to increase the local employment opportunities for South Australians.

Australia’s Federal Assistant Infrastructure and Regional Development Minister Jamie Briggs said the Darlington upgrade was an important project for southern commuters.

Briggs said: "The Darlington upgrade will deliver significant travel time savings for commuters travelling through this section of South Road, particularly during peak periods.

"In March, we announced an improved design, which will allow thousands of motorists and freight operators travelling to and from Flagstaff Road, Main South Road and the Southern Expressway to avoid three sets of traffic lights."

Major construction works are scheduled to begin later this year with completion of the Darlington upgrade expected by the end of 2018.

State transport and infrastructure minister Stephen Mullighan said: "The contenders’ local industry participation plans will be weighted by 15% as part of the tender process.

"That means local South Australian businesses and employees will leverage the maximum benefit available from the project."

Kellogg, Brown and Root, SMEC Australia and Jacobs Group have been identified by Gateway South as its exclusive design coalition for the project, while Lend Lease have engaged design firms ARUP, Parsons Brinkerhoff and Golder to support their bid.