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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 10.5 kilometre 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 underground tunnels and delivered in two stages:

  • Stage One: Southern Tunnel - Linking Anzac Highway to Darlington
  • Stage Two: 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

Currently, more than 110,000 vehicles use parts of South Road and its parallel alternate routes in a north-south direction each day. Further, 100,000 vehicles travel in an east-west direction through key intersections on South Road. With four out of the six key intersections almost at capacity, a solution to bust congestion is of critical importance to support South Australia’s growth.

When this section is complete, motorists will be able to travel from the River Torrens to Darlington in around eight minutes, bypassing 21 sets of traffic lights and saving up to 24 minutes in travel time per trip.

The project will also deliver a wide range of social, economic, environmental and safety benefits, not only for Adelaide, but for South Australia, including:

  • Supporting up to 4,000 jobs during construction and building a skills legacy for future projects
  • Around 60% of the motorway will be in underground tunnels – meaning less impacts to the surface and communities
  • Removing more than 110,000 daily vehicle movements from Edwardstown and Thebarton into underground tunnels
  • Improving the connectivity of the east-west transport network
  • Better access to travel gateways including Adelaide Airport, the Port of Adelaide, and national highways
  • Safer, more reliable and efficient journeys
    • Bypassing 21 sets of traffic lights
    • Shaving up to 24 minutes off the existing River Torrens to Darlington journey
    • Busting congestion at notorious key intersections
  • Improving South Australia’s competitiveness through the provision of efficient access to and from key freight areas
  • Preserving sites of cultural importance
  • 78 km of non-stop travel from the north to the south of Adelaide
  • Creating opportunities for urban renewal and place-making for local businesses and residents through a dedicated City Shaping Program
    • New and upgraded walking and cycling paths
    • New and improved green spaces and recreational areas
  • Providing better connections, bringing communities together

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 consist of approximately 6km of motorway, of which over 4km will be tunnels.

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 NSC 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 up to 4,000 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 preferred hybrid+ option:

  • 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.”

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


Facebook:     @DFITSA