The line is single track for most of its length, from Celtic Avenue, near Mitchell Park station, to its terminus.

Construction of the plant had commenced in 1963, and the assembly line was opened in October 1964, remaining operational until it was closed in March 2008.

[4] In July 2008, a feasibility study was commissioned by the government to extend the line to Flinders Medical Centre.

An elevated single track, with a pedestrian and bike path, was to begin just north of the original Tonsley station site, and cross Sturt Road, Laffer's Triangle and Main South Road, before terminating at Flinders station.

[12] Built concurrently with the adjacent Darlington Upgrade for the Southern Expressway,[13][14] major works took place from July 2019 to October 2020.

[15][16] The line was temporarily closed after the last service on 20 November 2020 for the extension to be commissioned, and fully reopened on 29 December.