South Eastern Freeway Upgrade

Under Delivery
South Eastern Freeway Upgrade

The South Eastern Freeway Upgrade Project will involve a major refit and upgrade of the Heysen Tunnels, to the south-east of Adelaide in South Australia.

This project will aim to address current tunnel elements that are at the end of their service life, including works to repair tunnel lining and add monitoring equipment, enhance ventilation, improve safety and lighting, and provide improved traffic management and incident response capabilities.

The project will add Managed Motorways components to the section of freeway, including new gantries, variable messaging signage, boom gates and land use management signage. 

The Heysen Tunnels are twin tube road tunnels, each approximately long, under Eagle On The Hill in the Mount Lofty Ranges in South Australia. The section forms part of the most direct road connection between Adelaide and Melbourne. 

Key Dates

Mar 2023 Contract Award
Mar 2023 Construction Commencement
Jun 2027 Expected Construction Completion

Funding contributions

Federal Government
SA Government


Procuring Agency: SA Department for Infrastructure and Transport
Successful Tenderer: Managing Contractor - McConnell Dowell Constructors


Mar 2023 The Federal Government announced McConnell Dowell Constructors had been appointed as the Managing Contractor for the works. Initial upgrades, including additional investigation works and the start of tunnel lining repairs, were to commence from 19 March 2023.
May 2024 The 2024-25 Federal Budget allocated an additional $100 million to the project, bringing the total Federal Government contribution to the project to $220 million.
Jun 2024 The 2024-25 SA Budget allocated an additional $100 million to the project over three years, increasing the total estimated cost to $350 million, with $67 million allocated to the project in FY2024-25.