The funding includes $66.4 million across the next four years to be allocated in this month's state budget.

It will allow for station makeovers to ensure they are safer and more enjoyable for train commuters.

Premier Steven Marshall said the funding would encourage more people to leave their cars at home and catch public transport.

"We know that if we can get more people onto our buses and trains it will help to ease traffic congestion on our roads and reduce the impacts on the environment," Mr Marshall said.

The station upgrades will include new shelters, seating and bins, lighting upgrades, painting, and landscaping, and are expected to create more than 100 jobs.

Also on Wednesday, the Labor opposition said it had seen leaked documents that showed the government would allocate more than $80 million in the budget to build a new high school in Adelaide's eastern suburbs.

It said the school was planned to open in 2023 with year seven students, with others enrolling from the following year.

Education spokesman Blair Boyer said it would be interesting to see Education Minister John Gardner justify building a new school in his own electorate when departmental officials had identified other areas in need.

Treasurer Rob Lucas will hand down the state budget on June 22.

Australian Associated Press