The 10-year long agreement will spread funding across the city and direct millions into future technology projects.

Prime Minister Scott Morrison, Premier Steven Marshall and Lord Mayor Sandy Verschoor came together to sign the deal in Adelaide on Tuesday.

Mr Morrison said the deal would improve the long-term liveability of the city.

"The big challenge we have to manage is how we manage population growth," he told reporters.

"The cities deal ... is about investing in the cultural life of the city, in the arts precinct (and) recognising the tremendous living indigenous culture that is so alive and so celebrated here in South Australia."

At the centre of the deal is the city's Lot Fourteen innovation precinct, which will host the headquarters of the Australian Space Agency and other cultural attractions, tech businesses and education facilities.

The funding will also investigate initiatives such as smart parking and CCTV in the CBD, and invest in key tourism projects like the Heysens Gallery at Hahndorf.

While in Adelaide, Mr Morrison also announced two local intersections will be upgraded under the government's urban congestion fund package.

The state and federal governments will each contribute $30.5 million to upgrade the Cross Rd and Fullarton Rd intersection, and $49 million to widen Portrush Rd on approach to the Magill Rd intersection.

Mr Marshall said the various funding commitments will transform South Australia and ready the state for the future.

"(The funding) will really create great economic activity, increase visitation, increase international students and, of course, bust some of the congestion on our roads," he said.

Australian Associated Press