The six rail lines run into Adelaide railway station in the CBD. They are:
- Gawler Line: runs north from Adelaide station with a length of 42 kilometers. The line is terminating at the Gawler Central station, which is located in the South Australian town of Gawler. The line is the most frequent and heavily patronized in the whole network. On weekdays some services terminate at Salisbury and Gawler.
- The Seaford line is 35 kilometers long and runs south from Adelaide and terminates at Seaford railway station.
- Tonsley line is a four-kilometer branch that belongs to the Seaford line and was running to Tonsley station until its closure in 2019. The original plan was to remove the station and replace it with the Flinders station. However, residents submitted a petition to keep it, so the new strategy was to build a new one about 200 meters away from the Tonsley station that will replace the current Clovelly Park station.
- The Outer Harbor line runs north-west from Adelaide station for about 22 kilometers and terminates at Outer Harbor. On weekdays some services terminate at Osborne railway station located in the north-western Adelaide suburb.
- Grange line is a six kilometers branch that belongs to the Outer Harbor line and is running to Grange.
- The Belair line runs south-east from Adelaide station for 22 kilometers, winding through the Adelaide Hills and terminating at Belair. On weekdays some services terminate at Blackwood.