Beginning at Schwabstraße and heading towards Hauptbahnhof, the schedule is as follows: If there are additional trains, these times repeat at 15- or 30-minute intervals (which means that during rush hour the S4 will depart on e.g. 07:03 AM, 07:18 AM, 07:33 AM and 07:48 AM).

Simultaneously, the Stuttgart streetcar company was embarking on plans to build tunnels downtown for their system.

Additionally, extra tracks were added to several outlying rail corridors in preparation for eventual S-Bahn service.

Work was completed in September 1978 and operation of the Stuttgart S-Bahn began with three lines (all beginning at Schwabstraße station): the S1 to Plochingen via Esslingen, the S4 to Ludwigsburg and the S6 to Weil der Stadt via Feuerbach and Leonberg.

Over the following years, the network has been extended to Bietigheim, Backnang and Schorndorf (1981) and the southern branches to Böblingen (1985), Herrenberg (1992) and Airport (1993).

The trains operate on the standard gauge tracks of the Deutsche Bahn AG (DBAG) and are powered by single phase AC at 15 kV and 16.67 hertz, taken from overhead wires.

All seven S-Bahn lines travel under the downtown area to Schwabstraße, and three continue on to Vaihingen through a dual-track tunnel.

[4] The final report, published in early 2019, concluded that headways in the central core section of the network could be reduced by some 20 percent.

Based on the introduction of ETCS, the train operating contract was extended to mid 2032 and 56 further S-Bahn trainsets were to be purchased.

Maintenance of the trains and power units takes place in the S-Bahn service yard at the original eastern terminus of line S1 in Plochingen.

[9] It was decided that the retractable step feature would be disabled and Class 430 trains will be gradually introduced beginning on December 15, 2013.