The formation of TransAdelaide was a prelude to competitive tendering and the introduction of private operators into the Adelaide public transport network.

These were initially structured as three independent divisions of the STA: In 1975, the Whitlam federal government proposed a nationalisation program for Australia's railways.

After formation of the Rail Division on 8 December 1975, the STA continued to administer and operate all the ex South Australian Railways (SAR) on behalf of the Federal government.

In past years, one feature of Adelaide's railway system was the number of industrial branch lines which were intended mainly for freight, but were also provided with passenger trains at peak hours.

Keeping Track was the STA's house journal that was founded by the SAR in August 1973 when Rail News was renamed.