Major works begin to create a non-stop South Road

Main construction works are officially underway on the largest and most complex infrastructure project (at Adelaide) in South Australian history.

Heavy machinery is on site and construction activity has ramped up at the Southern Precinct in Clovelly Park, marking the start of major works on the River Torrens to Darlington (T2D) Project that will create a non-stop South Road.

The non-stop South Road project will allow motorists to bypass 21 sets of traffic lights between the River Torrens and Darlington, saving up to 40 minutes of travel time in peak hour traffic.

It’s estimated up to 550 workers will be employed at the Southern Precinct during peak construction, with the entire T2D Project to support approximately 5,500 jobs per year during main construction – with 90 per cent of labour hours to be undertaken by South Australians.

The $15.4 billion T2D project is jointly funded by the Albanese and Malinauskas Labor Governments, with each contributing $7.7 billion. 

The Southern Precinct – located between Tonsley Boulevard and Norrie Avenue on the western side of South Road – will become the purpose-built site from where the Tunnel Boring Machines (TBMs) will launch to construct the southern tunnels.

Two TBMs will launch from the Southern Precinct to construct the twin 4.5km Southern Tunnels, while the twin 2.2km Northern Tunnels will utilise a third TBM. TBM works for the Southern Tunnels are planned to begin in the second half of 2026.

The past few weeks have seen a significant increase in works on site, including the start of construction of the diaphragm walls for the TBM launch box – the first piece of permanent works on the project. 

The diaphragm walls will be up to 35m deep and form the outside of the TBM launch box – a large open trench where the TBMs will be assembled and then begin excavating the tunnels.

A nearly 100m-long bentonite plant has also been constructed. This will produce and recycle bentonite slurry – a wet clay that is pumped into the trenches being excavated for the diaphragm walls to ensure ground stability. A water treatment plant, which will help the project treat and reuse water during the tunnelling process, has also been constructed.

The project will leave a skills legacy for South Australia, with the Alliance committing to a minimum of 6 per cent Aboriginal employment, more than 600 jobs for apprentices and trainees, and opportunities for more than 220 long-term unemployed people.

The Southern Precinct site has already undergone a transformation, with the Tonsley East Substation – which will supply electricity to the TBMs and then to the Southern Tunnels once they are completed – built on the precinct in 2023.

A link road between Selgar Avenue and MAB Circuit in Tonsley was constructed in 2023 on the western side of the precinct, one of a number of upgrades to surrounding streets to maintain local connectivity.

The Alliance awarded its first package of works for a $6 million link road between Norrie Avenue and English Avenue, Clovelly Park, which is being delivered by local contractor, McMahon Services. The new link road opened to traffic on Sunday, 11 May 2025.

These works will enable the planned temporary closure of Celtic Avenue, which is necessary for the construction of the Southern Tunnel portal and the TBM launch area. The new signalised intersection will maintain connectivity to and from South Road for the local community during this closure. 

The three TBMs were purchased in September 2024 from world-leading manufacturer Herrenknecht based in Schwanau, Germany.

The TBM components are being manufactured in Germany and China, before being assembled and factory assurance tested in China, and then delivered to Adelaide by ship. The first of three TBMs is expected to arrive in late 2025.

Two additional, smaller TBMs will also be used to carry out excavation work for cross passages between the main tunnels.

The T2D Alliance team will be regularly engaging with the local community, including at information sessions held along the alignment, to share updates and answer any questions they have about the project.

Quotes attributable to Premier of South Australia Peter Malinauskas:

“Today is such an important day for our state with the start of major construction to create a non-stop South Road.

“This is a project that’s been long talked about – everyone knows how important it is. Now we’re getting on with delivering it!

“Residents in the Tonsley and Clovelly Park areas will be seeing works underway at the Southern Precinct between Tonsley Boulevard and Norrie Avenue.

“The purpose-built site is where the Tunnel Boring Machines will launch to construct the 4.5km Southern Tunnels, which will run from Clovelly Park to just south of the Glenelg Tramline in Glandore.

“This massive precinct, which is approximately 1300 metres long and 100 metres wide, will feature three large rigs and associated cranes to build the retaining walls, a 500-tonne gantry crane initially to lift and place the TBM components, multiple storage sheds including a large spoil handling facility and a large enclosed conveyor system to shift ground material from the tunnels to the spoil handling shed.

“SA is building – and we are now building a non-stop South Road that will leave a legacy for generations.”

Quotes attributable to Minister for Infrastructure, Transport, Regional Development and Local Government Catherine King: 

“The start of major works on South Australia’s biggest ever road project is a significant milestone for the state.

“This is the last leg of a long journey to create the North-South Corridor – 78km of non-stop, traffic light-free motorway – and once complete, it will change the state for the better. 

“When South Australian’s can bypass 21 sets of traffic lights on their journeys between River Torrens and Darlington, they won’t know themselves.” 

Quotes attributable to SA Minister for Infrastructure and Transport Tom Koutsantonis:

“We’ve wasted no time in getting on with the largest infrastructure project in South Australian history.

“The T2D Alliance has awarded its first package of works, with local company McMahon Services already delivering an important link road between Norrie Avenue and English Avenue in Clovelly Park, which will help maintain access to and from South Road during T2D main construction.

“We have full confidence this State-shaping project will be open to traffic as promised by 2031, if not even earlier, providing South Australians with a range of transport, safety, economic and social benefits.”

Quotes attributable to Federal Member for Boothby Louise Miller-Frost, :

“This is yet another demonstration that the Australian and South Australian governments are investing in the infrastructure Adelaide needs to keep up with growing demand.

“Once completed, the T2D project won’t just benefit locals in my electorate and beyond, but also the millions of tourists who visit the area each year.” 

Quotes attributable to Federal Member for Adelaid Steve Georganas:

“This is a significant project that, once completed, will create four kilometres of twin three-lane tunnels to the south and 2.2 kilometres to the north, connected by open motorway.

“This project, which is jointly funded by the Australian and South Australian Governments, will bring much relief to travellers by saving time in traffic, and it allows South Australia to keep up with the demands on the state.

“I’d like to thank the community for their patience while we deliver this transformative infrastructure project.” 

Quotes attributable to State Member for Badcoe Jayne Stinson:

“My community knows how important a non-stop South Road will be for South Australia, and just wants to see this project underway.

“It’s fantastic to see major works kick off, and construction really ramping up before the tunnelling work kicks off.”

Quotes attributable to State Member for Elder Nadia Clancy:

“The Southern Precinct is really taking shape, and I’m so grateful to residents around the site for their incredible patience as the Government delivers this incredibly significant project.

“The completion of the new link road between Norrie Avenue and English Avenue in Clovelly Park will be a huge help for local motorists during other necessary closures.”