Clearing the way for the Torrens to Darlington (T2D) Motorway

Upgrading key infrastructure to cut delays and improve safety

In 2024, the Department for Infrastructure and Transport (DIT) appointed the Tram Grade Separation Projects Alliance (TGSPA) – comprising CPB Contractors, McConnell Dowell, Mott MacDonald, Arup, the DIT and sub-Alliance partner, Aurecon – to remove three congested tram level crossings and upgrade the South Road Tram Overpass to accommodate the River Torrens to Darlington (T2D) Project Open Motorway.

The project aimed to improve safety and network reliability for commuters, less time waiting in peak-hour traffic, and provide better connectivity for trams, cyclists and pedestrians.

We played a central role in the Alliance, providing bridge and civil design expertise from initial concept and detailed design through to fabrication, assembly and installation oversight.

Key works

The $870 million project included:

• South Road Tram Overpass Upgrade to accommodate the River Torrens to Darlington (T2D) Open Motorway.
• Removal of three level crossings at Cross Road and Marion Road (Plympton), Morphett Road (Morphettville).
• Road network upgrades, including intersection improvements at Morphett Road and Anzac Highway, and Marion Road and Anzac Highway.
• Tram network enhancements, including upgrades to the Brighton Road tram turn-back facility, installation of new converter stations at Black Forest and Plympton, and improved Mike Turtur Bikeway and Shared Use Path connections.
• Modifications to tram infrastructure at South Terrace, enabling temporary stabling of trams and allowing services to continue operating in the CBD during the Glenelg line closure.
• Construction of new community recreational spaces under the new overpasses.

Engineering leadership within an alliance model

As part of the TGSPA, our team:

• Led and supported bridge design for major overpass structures, including the South Road Tram Overpass.
• Worked collaboratively with Alliance partners to accelerate design and construction sequencing.
• Supported constructability-focused solutions to enable rapid delivery within tight timeframes.
• Ensured designs integrated with future transport infrastructure requirements, including adjacent major road upgrades.

Digital engineering management played a key role in aligning disciplines and interfaces within the integrated alliance framework. A shared digital model provided a single source of truth, supporting real-time coordination, streamlined approvals and improved engagement with stakeholders through clear visualisation of complex designs and construction challenges.

Designed to support Adelaide’s future network

With the completion of these works, the project delivers wide-ranging benefits for tram and road users alike, including:

• Improved safety, accessibility and travel time reliability
• Creation of new open spaces, amenities and urban landscaping

The TGSPA demonstrates how an alliance delivery model, underpinned by deep technical expertise and collaborative design, can unlock fast, high-impact urban transport upgrades, even in highly constrained environments.