Major projects reach major milestones as South Australia builds

Significant milestones have been reached on two of the state’s most important transport infrastructure projects, as the Australian and South Australian governments deliver on election commitments south of Adelaide.

In a major benchmark for the $120 million Majors Road Interchange project, 18 South Australian-made girders have now been installed for the widening of the Majors Road bridge.

At the same time, a new interchange and realigned intersection of Aldinga Beach Road and Aldinga Road – a major piece of infrastructure in stage two of the Main South Road duplication from Aldinga to Sellicks Beach – is starting to take shape.

The interchange will see the Aldinga Beach Road and Aldinga Road junctions realigned, and an underpass built at the intersection of Main South Road with the newly realigned roads.

At Majors Road, the girders – ranging in length from 23 to 31 metres and each weighing between 8 and 14 tonnes – were installed over four night shifts using a 300-tonne crane.

They will allow the existing Majors Road bridge to be widened from the current two lanes to six lanes, including two through lanes and a dedicated right turn lane, onto the Southern Expressway, in each direction.

As well as increased bridge capacity, the Majors Road Interchange project will see the construction of new on and off-ramps for the Southern Expressway at Majors Road.

Majors Road is an important arterial road in the southern suburbs, carrying around 13,200 vehicles per day, and is anticipated to reach around 14,700 during peak times by 2036.

The Southern Expressway carries approximately 74,000 vehicles per day between Darlington and the Reynella interchange and supports economic activity in Adelaide’s southern commercial and industrial areas and facilitates tourist travel on the Fleurieu Peninsula.

The girders were constructed by local company Bowhill Engineering, using 100 per cent regional South Australian labour, including 13 apprentices that worked on the project.

Each girder was transported almost 150 kilometres after their fabrication in Bowhill to the Majors Road worksite.

Bowhill also fabricated the original 16 girders used in the initial Majors Road bridge construction.

The Majors Road Interchange project is jointly funded by the Australian and South Australian governments, which each contributed $60 million, and is expected to be completed at the end of 2025. It is supporting approximately 245 full-time-equivalent jobs per year over the construction period.

Meanwhile the Aldinga Interchange begins to take shape, with piling works now underway.

Piling is the construction of columns in the ground that will provide vertical and horizontal support to the underpass and bridge structure, creating a strong and stable foundation.

Above the 53 piles currently under construction, the new underpass will have twelve 40-tonne girders supporting a bridge deck 26 metres long and 27 metres wide. The bridge deck will also feature 62 architectural panels and 86 metres of anti-throw screens.

The first permanent new asphalt section on Main South Road between Hart Road and Old Coach Road on the western side of the underpass is now open to traffic. This section of roadway will later become the permanent northbound on and off ramps.

The underpass will be made up of 39,200 tonnes of asphalt to create 86,000 square metres of road pavement, with more than 15.5 linear kilometres of soil nails supporting the underpass walls.

Stage Two of the Main South Road duplication between Aldinga Beach Road and Sellicks Beach is being delivered as part of the $810.4 million Fleurieu Connections project, with the Australian Government contributing $221.6 million and South Australian Government contributing $588.8 million.

As well as the Aldinga Beach Road interchange, the duplication includes intersection upgrades at Hart and Colville roads, Norman and Rogers roads, Hahn and Cox roads, and Sellicks Beach Road plus installation of wide centre medians and wire rope barriers to improve safety by separating northbound and southbound traffic.

It also includes three U-turns to facilitate local access and a shared use path for pedestrians and cyclists along the western side of Main South Road, from Aldinga to Sellicks Beach.

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

“The Australian and South Australian Governments are delivering the infrastructure projects that improve the lives of South Australians.

“The Majors Road Interchange project will have significant benefits for the many thousands of people who pass through the area each day, reducing travel times and providing safer and more reliable journeys.

“It will also provide better connections to local sporting and recreational facilities, improve access for emergency services vehicles and take trucks off local streets.”

Quotes attributable to South Australian Minister for Infrastructure and Transport, Tom Koutsantonis:

“SA is building, and we are continuing to get on with the job of delivering infrastructure projects to improve the lives of South Australians.

“It’s great to see another milestone reached on Majors Rd with the installation of the bridge girders, locally produced by a South Australian company.

“Work is also well underway on doubling the capacity of Main South Road from Aldinga to Sellicks Beach, which will support growing communities and create faster and safer journeys.”

“This interchange at Aldinga is the biggest single piece of infrastructure in this second stage of the Main South Road duplication. Drivers will now travel on the first new section of asphalt as work to dig out the underpass and build the bridge continues, while the interchange begins to take shape.”

Quotes attributable to Federal Member for Kingston Amanda Rishworth:

“It is great to see works progressing at Aldinga Interchange, with construction set to be completed in 2026.

“In the meantime, this project is supporting more than 400 full-time jobs each year during construction, which is great for the Kingston community.”

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

“It’s great to see this significant milestone on the important Majors Rd project that will give southern commuters direct access to the Southern Expressway – which in turn will help take commuter traffic off Brighton Road in Boothby.”

Quotes attributable to State Member for Davenport Erin Thompson:

“We’ve been very conscious to minimise any impact on Glenthorne National Park as we meet this significant election commitment to build a new off-ramp for Majors Rd commuters.

“The fact that the Friends of Glenthorne have been vocal supporters of our approach is a fantastic vindication of our consultative approach.”