The Morrison government is injecting an additional $2.26 billion into Adelaide's so-called North-South corridor, a project that will deliver 78 kilometres of non-stop motorway once complete.
The new funding will bring the federal government's total commitment to the project to $6.8 billion.
"Our government, together with the Marshall government, is getting on with delivering what is the most significant infrastructure project ever undertaken in South Australia," Prime Minister Scott Morrison said in a statement on Sunday.
"The investment in this project alone is expected to support around 4900 jobs and slash travel times by up to 20 minutes between the River Torrens and Darlington and help ensure South Australians get home to family and friends safely."
Premier Steven Marshall said the partnership with the Morrison government enables projects that make a real difference to the everyday lives of South Australians.
"This once-in-a-generation project is going to create a record number of jobs for South Australians and underpin the construction industry for the next ten years," Premier Marshall said.
