The Ammer Valley Railway (Ammertalbahn) runs through the German state of Baden-Württemberg, connecting the university town of Tübingen with Herrenberg in the Böblingen district.

Not least, a citizens' initiative had opposed the approach advocated by Tübingen mayor Hermann Haußer for the rail project.

[4] On 26 July 1995, the Zweckverband ÖPNV im Ammertal ("municipal association for public transport in the Ammer valley", ZÖA) was established and bought the line from Deutsche Bahn in 1996.

The 4.1 kilometres (2.5 mi)-long section between Gültstein and Herrenberg was rebuilt enabling the line to be reactivated for passenger services over its full length on 1 August 1999.

The single-track, non-electrified line was completely modernised and prepared for operations at up to 100 kilometres per hour (62 mph).

The line is operated using direct traffic control (Zugleitbetrieb) with the train dispatcher located in the Tübingen signalbox.

[5] The number of passengers transported on the railway line on average per day rose steadily from 5,150 at the end of 1999 to 2009, by a total of 53% to 7,890 and a further 9% to 8,588 in 2019.

This 1.4 kilometres (0.87 mi)-long double-track section begins behind the Ammer bridges and ends shortly before the Unterjesingen Mitte station.

According to 2012 figures (at 2006 prices), the estimated cost of the duplication of the two sections (4 km in total), the electrification of the whole line (including the Schlossberg tunnel) and the construction of a new main platform amounted to €27.8m.

[8] In the Hardtwald area, the swampy subsoil caused problems, so the foundations of the existing track had to be rebuilt.

At the timetable change in December 2022,[16] electric operations began every 30 minutes from Herrenberg via Tübingen to Bad Urach.

These were modernised in the course of 2023, equipped with Wi-Fi and request stop buttons and repainted in bwegt (Baden-Wurttemberg public transport) colours.