Adelaide is Australia's only mainland capital city without a non-stop motorway in its metropolitan area. The existing transport network is struggling.
The T2D Project is the final 10.5km section of the North-South Corridor, and will complete 78km of non-stop, traffic light-free motorway.
Improved travel efficiency, increased road safety and better active transport links will enhance economic development and improve accessibility for SA.
Adelaide is currently Australia’s only mainland capital city without a non-stop motorway in its metropolitan area. With 120,000+ vehicles using the South, Marion and Goodwood Roads each day the existing network is congested. The T2D section of South Road also experiences significantly higher crash rates that the Northern and Southern Expressways.
Recent research shows daily car trips across Adelaide are expected to increase by 26% by 2031. That's up to 6.2 million car trips each day. Without action, congestion on the existing network will worsen and could cost the South Australian economy more than $230 million each year in lost productivity.
The $15.4 billion T2D Project is the final section of the North-South Corridor and will deliver 10.5km of non-stop motorway between the River Torrens and Darlington, completing the 78km North-South Corridor and significantly contributing to the economic growth and development of Adelaide and South Australia.
The Project involves constructing two sets of twin tunnels – the Southern Tunnels and the Northern Tunnels and both tunnels will have three lanes, and will be connected by an open motorway.
Arcadis is part of the T2D Alliance, comprising John Holland, Bouygues Construction Australia, Jacobs and Ventia. Both Arcadis and Jacobs are the designers for the Project. The scope includes the detailed design for the Tunnel, Civil, Structural and Building Services.
The Project will bring a significant transformation at the surface level, incorporating new tunnel entry and exit portals, active transport connections, community amenities and green spaces. New east-west connections will be added across the motorway for pedestrians and cyclists, alongside approximately 26 hectares of new parks, natural systems, and public realm space.
More trees will be planted, increasing the existing tree canopy by over 20% along the alignment. A dedicated north-south linear shared-use path will connect to the broader cycling network, and multiple new ‘kiss and drop’ areas near schools will enhance access and convenience. The urban design concept thoughtfully integrates both traditional and contemporary connections to the land, celebrating and enhancing the area's history and culture while creating a vibrant surface landscape.
The T2D Project will bring significant transformation to Adelaide, including an upgraded transport corridor, active transport links, community amenities and green spaces. It will enhance economic development by improving productivity and accessibility for freight vehicles, supporting local and regional businesses.
The Project will also improve travel efficiency for people moving north-south and east-west, strengthen connectivity to northern and southern suburbs, and create opportunities for better land use and job growth in these areas.
It will expand the North-South Corridor, improving connections to key travel gateways, such as Adelaide Airport, Port Adelaide, and the national highway network. T2D will also increase road safety, reduce crash risks, and improve public transport efficiency. The T2D Project will support over 5,500 jobs annually during main construction and will enhance South Australia's construction capacity. It will also foster workforce development, offering apprenticeships and training opportunities, as well as encouraging participation from women and Aboriginal communities.
Investment in workforce development will ensure a resilient labour pipeline, supporting the long-term growth of South Australia's businesses and suppliers.
PROJECT HISTORY
