Frequently Asked Questions

The Australian and South Australian governments have committed $150 million (80:20) to upgrade the Mount Barker and Verdun interchanges.

The project aims to improve connectivity to the South Eastern Freeway and improve the capacity of the interchanges in response to existing and projected growth for Mount Barker and the Adelaide Hills area.

The project is expected to support approximately 260 full-time equivalent jobs per year over the construction period.

The existing Mount Barker Interchange will be upgraded to include a new three-lane bridge across the South Eastern Freeway for northbound traffic, with the existing bridge converted to accommodate three lanes of southbound traffic and a new Shared Use Path. It will also include improved ramp capacity and new traffic signals to improve safety and reduce congestion.

Key features include:

• a new three lane bridge over the South Eastern Freeway for northbound traffic;
• conversion of the existing bridge to accommodate three lanes of southbound traffic;
• a new signalised intersection at Adelaide Road and the freeway exit ramp from Murray Bridge;
• upgrades to the existing ramps to and from Adelaide to improve safety and capacity;
• a new bus priority lane;
• a new Shared Use Path;
• a new northbound on road bike lane; and
• improved accessibility and safety for Adelaide Road service road.

Major construction at the Mount Barker Interchange is planned to start in late 2025. The interchange is expected to be open to traffic in late 2027.

We expect the roads will remain open for most of the construction period with speed and lane restrictions in place, however, it’s likely there will be some temporary closures to tie into existing road infrastructure.

We will continue working on minimising any impacts to road users and the community wherever possible and will provide more information on traffic impacts as it becomes available.

We encourage you to subscribe for updates to receive the latest information about the project.

The concept design indicates that there will be some impact to existing vegetation and trees located at the intersection. As the design progresses, further details will be made available regarding any vegetation impacts.

We’re aware that there is a significant River Redgum in the reserve adjacent the existing Mount Barker Interchange bridge, known as “Old Man Barker”. We can confirm that this tree will be retained, and there are no plans to remove it as part of the project.

Fauna considerations form part of the Department for Infrastructure and Transport’s standard Environment and Heritage Impact Assessment processes. Ecological assessment will be undertaken to identify fauna habitat and ecological communities to assist the design.

We understand the ecological importance of roadside vegetation and will continue to minimise potential impacts to vegetation and fauna in the next stage of design.