Frequently asked questions about the Adelaide Road, Mount Barker Roundabout Upgrade

What funding is available for this project?

The South Australian Government has committed $40 million to upgrade the roundabout located at the intersection of Adelaide Road, Alexandrina Road, Wellington Road, and Flaxley Road in Mount Barker.

This has been identified as a priority upgrade within the Mount Barker Infrastructure Deed, which will support nearby residential developments occurring within the Mount Barker Urban Growth Area and the broader Mount Barker area.

Why is this project needed?

The preferred design will improve traffic capacity, safety and connectivity for road users at the intersection to support growth in the Mount Barker area.

On average, approximately 31,000 vehicles travel through the existing Mount Barker roundabout per day. Traffic volumes on these roads and the associated delays are expected to increase significantly as a result of development occurring throughout the Mount Barker Urban Growth Area, particularly during the peak periods.

Between 2019 and 2023, at the intersection of Adelaide Road, Wellington Road, Flaxley Road and Alexandrina Road, there were five reported crashes, consisting of one serious injury crash, two minor injury crashes and two property damage crashes.

Mount Barker is a regional centre within Adelaide Hills and is expected to become South Australia’s second largest city, after Adelaide. The roundabout supports local and regional traffic within and surrounding Mount Barker and includes several walking and cycling connections.

The existing roundabout has previously been identified as requiring improvement and is also identified under the Mount Barker Road Infrastructure Deed as requiring an upgrade to support nearby developments and future traffic growth within the Mount Barker Urban Growth Area.

What is planned?

The project will include a new dual lane roundabout at the intersection of Adelaide Road, Alexandrina Road, Wellington Road and Flaxley Road that will cater for the increase in traffic.

Adelaide Road and Flaxley Road will receive new signalised pedestrian actuated crossings, while the existing crossing on Wellington Road will be relocated to improve safety. The roundabout will also include new Shared Use Paths to improve connectivity and improvements to road lighting.

The intersection of Adelaide Road, Alexandrina Road, Wellington Road and Flaxley Road in Mount Barker is currently a dual lane roundabout with single lane approaches on some legs.

The design will include:

  • Additional traffic lanes on Flaxley Road, Wellington Road and Alexandrina Road.
  • Relocating a pedestrian actuated (push button) crossing on Wellington Road, approximately 50 metres south-east of the current location.
  • New pedestrian actuated (push button) crossing on Adelaide Road and Flaxley Road.
  • New pedestrian refuge on Alexandrina Road.
  • New Shared Use Path and bike on/off ramps.
  • New and upgraded lighting, line marking and drainage.
  • New asphalt and kerb and gutter.
  • New landscaping will be implemented at the roundabout.
How did you engage with the community?

In 2023 we sought feedback from the community to inform the design. The large majority of people who provided feedback described their attitude towards an upgrade at this intersection as ‘positive.’

Congestion and motorist safety were the main concerns raised by the community as the top two ranked “issues of importance.

Insights from the local community and key stakeholders, along with technical assessments, have played a key role in informing the design for the upgrade.

We will continue engaging with the community throughout the project. We encourage you to subscribe for updates to receive the latest information about the project and upcoming community information opportunities.

What are the benefits of this upgrade?

The design will improve roundabout performance and connectivity to support growth in the area, including the recently announced expansion of the Mount Barker Hospital.

Compared with other upgrade options, this design has:

  • Less property impacts
  • Less tree removals
  • A lower traffic impact on local streets
  • A lower impact on major underground services
  • Minimises disruption to road users during construction; and
  • Minimises impacts to parking.
Did you consider traffic signals?

Yes. Traffic signal options were considered during the early planning phase for this project. Traffic signal options have a bigger impact in terms of land acquisition, parking, vegetation, construction and are significantly more expensive.

The roundabout design solution has been chosen as the preferred option as it achieves relatively similar performance to a traffic light solution in terms of traffic flow and efficiency and achieves similar pedestrian safety objectives to a traffic light solution by providing safe, signalised crossing points for pedestrians on the roads approaching the roundabout.

What else did you need to consider in the early design process?

We also consulted with other stakeholders who are currently carrying out public works in Mount Barker including:

  • Mount Barker Hospital Upgrade
  • Mount Barker Interchange Upgrade
  • District Council of Mount Barker’s (Council) Integrated Transport Plan (ITP) Lead Strategy
  • Council’s review of its current Trails Plan (as part of a review of our Open Space Strategy
  • Adelaide Road and Keith Stephenson Park master plan
  • Mount Barker Township Entries
  • Arterial Road Corridor Management Plans.
Have improvements for people walking and cycling including school students been considered in the preferred concept design?

Yes. New Shared Use Paths will be provided, connecting into the existing path network which aligns with the corridor strategy to provide off-road share path movements. New on/off ramps will allow cyclists to negotiate movements around the roundabout off-road, improving safety for these road users.

Will vegetation removal be required?

The project has been carefully designed and staged to minimise vegetation impacts as much as possible, however removal of some vegetation is needed.

The design has been developed in collaboration with the Mount Barker District Council and a landscape architect to support local biodiversity and include species suited to the area.

Please refer to our Vegetation fact sheet for further information.

What is the project timing?

Works are planned to start in mid-2025, with the roundabout expected to be open to traffic in mid-2026 (weather permitting). We will continue to keep the community updated via our project website and community mailing list.

How do I contact the project or seek further information?
What can I expect during construction works?

Short-term pedestrian, motorists and cyclist detours may be required at times to safely facilitate works. Clear signage will be in place during these times to help maintain safe access and direct pedestrians and cyclists.

Speed and lane restrictions will be in place during construction. Signage and traffic controllers will help guide drivers, pedestrians and cyclists safely through the work zone. Construction activity and machinery can be distracting. Please stay alert when moving through the area.

Some noise and vibration disturbance may occur during construction. We will make every effort to minimise impacts. Please refer to our Construction Fact Sheet for more information.

What’s happening to the rotunda at Keith Stephenson Park?

To enable the widening of Flaxley Road as part of the roundabout upgrade, the existing rotunda has been removed, and a new rotunda will be installed prior to completion of the project.  The existing bench seats and existing signage will be reinstated.  We have worked with Council to determine the new location. References to the Herriot family will be retained.

Will drone and timelapse photography be used during construction?

Yes, drones may be used from time to time, within and around the project area to capture aerial imagery and video footage to monitor construction progress. Drone operations will be conducted in accordance with Civil Aviation Safety Authority (CASA) requirements.

As part of this project a time-lapse camera will be installed on site to record construction progress and key milestones.

Will there be road closures and detours while the roundabout is being upgraded?

Most roads will stay open during construction but expect speed and lane restrictions. Some brief road closures may occur to connect with existing infrastructure.

We will minimise impacts on road users and the community and provide traffic and detour updates as needed.

We are coordinating with emergency services and bus operators to keep public transport running and ensure emergency vehicles always have access.