It is based on the Karlsruhe model and operated jointly by the Albtal-Verkehrs-Gesellschaft (AVG), the Stadtwerke Heilbronn (SWH) and Deutsche Bahn (DB).

Immediately after the transition from EBO to BOStrab the tracks run in front of the Hauptbahnhof to the Hauptbahnhof/Willy-Brandt-Platz stop; the change in the electrical systems is shortly later.

Trains then leave running under DC next to Bahnhofstrasse (station street) to the NeckarTurm am Kurt-Schumacher-Platz stop at its eastern end.

Subsequently, the Stadtbahn runs on the north side of Bismarckstraße and Jägerhausstraße to Pfühlpark stop, beyond which the inner-city line ends.

A short ramp then carries the Stadtbahn back to the DB line, which then runs just past Trappensee station and through the Weinberg tunnel.

There they swing into Hans-Riesser-Straße (street) and follow it up to its eastern end and continue on to meet the tracks of the Franconia Railway, which they then runs next to.

There are also two pairs of "sprinters" that stop only in Heilbronn, Eppingen, Bretten and Karlsruhe-Durlach, which formerly continued once an hour as an express to Achern, but since 2012 have terminated in Karlsruhe.

An important step in this direction was made in June 1997 with the extension of Karlsruhe Stadtbahn line S4 to Eppingen in the western part of the Heilbronn district.

Construction started on 9 September 2003, including the demolition of the bridge of the closed Bottwar Valley Railway (Bottwartalbahn) over Jägerhausstraße since it would have obstructed the line’s overhead wire.

As part of the extension of the Stadtbahn line, Karlstor station, which was on the Hohenlohe Railway in the urban area, was closed.

[3] Stadtwerke Heilbronn GmbH were awarded a contract worth €1.2 million for the planning of the construction of the northern branch after a Europe-wide tender on 21 June 2007.

On 4 May 2005, the Heilbronn council considered work for a new line through the city to operate under BOStrab, which was expected to cost €59 million.

The Stuttgart Regional Council adopted the planning approval for the section through the centre of the city of Heilbronn on 13 January 2011.

Because of delayed approval for the use of EEO for the ET 2010 (part of the Bombardier Flexity Swift family) vehicles, the section between Kaufland and Neckarsulm was temporarily dedicated as a BOStrab line.

[8] Until the reclassification of the northern section of the line as an EEO route and its connection to the DB network in December 2014, Stadtbahn services could only operate as far as Neckarsulm.