The intersection of Portrush Road and Magill Road is part of the National Land Transport Network and forms part of the Outer Ring Route, which is a major traffic route and freight route connection from the South Eastern Freeway around the City of Adelaide.
Both Portrush and Magill Roads are also high frequency public transport corridors.
The upgrade will improve travel times and safety for all users including network reliability and economic productivity.
The major works contract for the upgrade of the intersection has been awarded to BMD Constructions.
The intersection will be open to traffic by the end of 2021 with completion expected in early 2022.
The $98 million project is jointly funded by the Australian and South Australian governments and supporting around 78 full time-equivalent jobs during construction.