Design changes

A Reference Design for the T2D Project was released in November 2021 showing the overall motorway layout and how it was proposed to operate along its entire alignment.

In response to a range of factors including community feedback on elements of the Reference Design and pressures in the Australian market for similar mega-projects, we considered the following key elements of the T2D Project:

Project design – particularly the elevated structures at Anzac Highway and next to Brickworks Marketplace, major intersections, connectivity to and from the motorway and the length of the tunnels
Off-corridor upgrades and scope – to ensure the broader traffic network will function effectively during construction and when the motorway is open
Early works and technical investigations – to ensure enabling works take place on time
Procurement approach – to maximise opportunities for South Australians and promote competition throughout the wider industry
Program schedule – to define a clear program for delivery that matches market readiness
Land acquisition – confirming requirements for land acquisition based on project design and construction requirement, and taking a flexible approach
Engagement – incorporating lessons learned from previous activities to ensure open and meaningful engagement with stakeholders and the community.

A review of the T2D Project was undertaken to ensure it will deliver the best possible outcome for road users and those who live and work along the corridor, represent value for money for South Australian taxpayers, create opportunities for local businesses and is realistic in predicated delivery timeframes.

Thank you for your patience while this important work was completed. This is a once-in-a-generation project, and it is critical that we get it right.

Northern Tunnels, northern portal

What we changed

You told us the visual impact of the proposed 12-metre overpass near Brickworks Marketplace was unacceptable.

The motorway has been moved to the east so the elevated structure next to Brickworks Marketplace can be removed and South Road northbound can now be at the surface. As a result, community open space has increased with less impact on Kings Reserve.

To achieve this, the southbound section of South Road will pass over the corner of Hindmarsh Cemetery. This lower structure will not impact access or plots within Hindmarsh Cemetery.

Benefits

This design change will:

improve visual amenity by removing the South Road northbound structure that was longer and much higher
reduce residential acquisition required and be less disruptive for motorists during construction
reduce impact on Kings Reserve making more of this open space publicly accessible during construction
increase community open space on the eastern side of motorway.

James Congdon Drive connection

What we changed

We added a southbound on-ramp from James Congdon Drive and a northbound off-ramp north of Richmond Road.

This will improve connection from the motorway to Adelaide Airport and the western suburbs and provide an alternative option to access the CBD and the Inner Ring Route.

To further enhance access to the CBD, we are adding right turns from James Congdon Drive to Sir Donald Bradman Drive.

We are also widening Richmond Road between South Road and Railway Terrace to provide two lanes in each direction. This will include an upgrade of the Richmond Road and Railway Terrace intersection. These changes will improve traffic flow along Richmond Road.

Collectively, these design changes will provide motorists with more choice, improved traffic flow and make the network more resilient.

Benefits

This design change will:

improve network connectivity
provide more options for motorists travelling to key destinations via the motorway.

Anzac Highway connection

What we changed

You told us that the visual impacts of the proposed Anzac Highway overpass and the removal of the right turn from Anzac Highway on South Road was unacceptable.

We removed the elevated structure that would have taken vehicles travelling from the south onto Anzac Highway towards the CBD.

Motorists travelling to the CBD from the south will continue to travel through the intersection using right turns from South Road onto Anzac Highway.

Right turns from Anzac Highway onto South Road have also been reinstated to improve connectivity.

The new northbound off-ramp north of Richmond Road will reduce traffic needing to use the South Road and Anzac Highway intersection.

Benefits

This design change will:

improve visual impact for the community
improve connectivity by reinstating right turns from Anzac Highway onto South Road
save around 100 trees.

Southern Tunnels, southern portal

What we changed

A technical review found that the tunnel portal needs to move approximately 300 metres to the north to improve traffic performance and safety. This design change will:

give motorists more distance and time to change lanes between Tonsley and the tunnel portal
provide better east-west connection via a shared-use bridge over the motorway
reduce long-term closures of the northern portion of the Darlington motorway during construction.

Benefits

This design change will:

improve safety for motorists by providing more road length and time to change lanes
provide better east-west connection via a proposed shared-use bridge over the motorway
reduce long-term closures of the northern portion of the Darlington motorway during construction
provide an opportunity for a school drop-off area.