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Frequently asked questions

What is the North-South Corridor - Torrens to Darlington project?

The Australian and South Australian governments are delivering the final and most complex section of the North-South Corridor. The 10.5km Torrens to Darlington (T2D) Project is the most significant infrastructure project ever undertaken in South Australia.

To deliver the project, we will build twin tunnels, lowered and ground-level motorways, new intersections, overpasses and underpasses, with details to be defined in the final Reference Design.

When complete, around 60% of the T2D Project will be tunnels and delivered in two stages:

  • Southern Tunnel - Linking Anzac Highway to Darlington
  • Tunnel Connector and Northern Tunnel - Linking River Torrens to Anzac Highway

The T2D Project will complete the North-South Corridor - 78km of non-stop motorway between Gawler and Old Noarlunga.

What is a Reference Design

A Reference Design is a high level design that establishes road alignment, tunnel layouts and motorway access points. It models motorway performance and identifies locations for laydown areas (the space needed to store construction materials and equipment). It considers the construction impacts, possible issues, constraints and benefits of potential design options.

The development of the Reference Design is informed by a project assessment process. This includes:

  • Ground investigations
  • Traffic modelling
  • Noise, vibration and air quality assessments
  • Flora and fauna impact assessments
  • Cultural and heritage assessments
  • Community and environmental impacts
  • Community views

Project Benefits

The T2D Project will deliver a wide range of social, economic, environmental and safety benefits, not only for Adelaide, but for South Australia.

It will:

  • support about 4,900 jobs during construction and build a skills legacy for future projects
  • revitalise Adelaide’s inner western and southern suburbs, stimulating retail and commercial opportunities leading to an additional 7,700 jobs in this area
  • reduce traffic congestion by taking 130,000 weekday vehicle movements into underground tunnels
  • improve travel times by about 20 minutes to deliver a nine-minute journey between the River Torrens and Darlington
  • provide better access to travel gateways, including Adelaide Airport, Port Adelaide and the national highway network
  • improve South Australia’s competitiveness by providing better access to and from key freight areas * create urban renewal opportunities for local businesses and residents through new and upgraded walking and cycling paths, green spaces and recreational areas.

How many tunnels are there?

Both stages of the T2D Project will include twin tunnels that are three lanes in each direction.

The first stage of the project, connecting Anzac Highway to Darlington, will be approximately 6km in length comprising  approximately 4.8km of tunnel.

The second stage of the project will link the River Torrens to Anzac Highway and will consist of surface motorway and tunnels.

When will construction begin?

Stage 1 (Southern Tunnel): Construction is expected to commence in late 2023 pending relevant approvals, and take approximately 4-5 years.

Stage 2 (Tunnel Connector and Northern Tunnel): Construction is expected to commence in 2026, subject to planning, approvals and funding.

When will the Project be completed?

The final 10.5km T2D section of the North-South Corridor is expected to be completed in 2030.

What stage of development is the T2D Project up to?

Following the decision to proceed with a hybrid+ option, our team are now working to ensure we have the best plan in place to minimise impact to properties, and deliver the safest, most reliable motorway possible.

The next stage in the project’s development is to produce a Reference Design and Final Business Case which are both expected to be completed in the second half of 2021.

Development of the Reference Design will be informed by more detailed technical investigations and engagement with the traditional owners of the land, residents, businesses, the community, road-users, businesses, and industry to better understand their views.

What sort of jobs and skills opportunities will there be?

From design to construction, the project will support about 4,900 jobs. These jobs include plant-operators, concreters, pavers, welders, electricians, pipe fitters, mechanics, engineers, health and safety professionals, to name a few, with the safety and wellbeing of the workforce being the top priority.

The South Australian Government will invest in local people to give them the opportunity to work on the biggest infrastructure project in the state, and build the skills required to work on projects in the future.

How are you protecting Adelaide's heritage sites?

We share the community’s view that progress and heritage can co-exist, and that as many local and state treasures should be preserved as is practically possible.

The chosen design, consisting of tunnels and lowered and ground-level motorways will:

  • Saves important heritage properties including Thebarton Theatre
  • Minimises impact on land along that section of the corridor
  • Maintains the area’s suburban, neighbourhood character

How is community feedback being taken into account?

As part of the T2D Project, Reference Groups have been established to provide an opportunity for residents, community interest groups, businesses and individuals to provide input into various aspects of the project during the planning and design phase.

The four reference groups for the T2D Project are:

  • Southern Tunnel: Community Reference Group and Business Reference Group
  • Northern Tunnel: Community Reference Group and Business Reference Group

There will be many opportunities to get involved and provide feedback on the T2D Project, all feedback will be captured and considered.

We’ll continue to engage with the local community, traditional owners of the land, road-users, businesses, and industry to better understand their hopes for and concerns about the project.

Community feedback is being incorporated into the reference design, with the project looking to minimise social, heritage and environmental impacts as much as practicable.

How will you work to support businesses?

The project is committed to working with businesses to minimise impacts resulting from planning, design and construction activities.

Lessons learnt, challenges and business experiences from previous projects are being considered as the department looks to better engage and support affected businesses to complement existing business support initiatives offered both within the department and across government.

Business Reference Groups have also been established as a means to contribute on behalf of organisations and other businesses to build and shape the design and identify potential social, economic and business impacts.

What is the City Shaping Program?

City Shaping embodies an approach to achieve outcomes that focus on people, places and programs. It includes consideration of the social, cultural and economic context of the communities along the North-South Corridor, Greater Adelaide and South Australia’s regions.

City Shaping leverages the investment of the North-South Corridor to facilitate urban uplift, renewal and revitalisation. It is a long-term approach that embodies the realisation of the social, environmental, economic and cultural potential of a place.

The T2D Project’s City Shaping vision is “Connecting communities and stimulating business investment along a greener, safer, more accessible South Road.”

Has everyone been informed who is going to have their property compulsorily acquired?

An options analysis was undertaken and was subsequently endorsed by Infrastructure Australia. As such, the project has a high level of confidence that the properties already identified for compulsory acquisition represent the final footprint of the T2D Project.

We will continue to make the minimisation of acquisition a priority as we move into detailed design development.

Are all the property acquisitions and crucial details of the T2D now public?

An options analysis was undertaken and was subsequently endorsed by Infrastructure Australia. As such, the project has a high level of confidence that the properties already identified for compulsory acquisition represent the final footprint of the T2D Project.

We will continue to make the minimisation of acquisition a priority as we move into detailed design development.

How do I stay up to date on the project?

You can subscribe to receive regular updates here

You can also contact our dedicated team via:

Phone:           1300 951 145

Email:             T2D@sa.gov.au

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