The Upper Neckar Railway was extended from there to the south as follows: When it was being built, the line between Tuttlingen and Möhringen an der Donau, which was initially single-track, crossed the border from Württemberg to Baden and also passed through the Province of Hohenzollern near Dettingen.

Württemberg therefore concluded a treaty with Prussia on 13 March 1865 and with the Grand Duchy of Baden on 18 February 1865, but built and operated the entire length of the line itself.

At the border station of Immendingen at the time, there was a connection to the Black Forest Railway that had opened two years earlier.

With the completion of the Stuttgart–Horb railway, the so-called Gäubahn, in 1879, the Plochingen–Horb section lost some of its importance because the direct connection from Stuttgart to the south ran through the Korngäu from then on.

In 1944/45, Allied aerial bombing caused serious damage to the stations in Horb, Rottweil, Spaichingen and Tuttlingen, but these did not interrupt traffic permanently.

After the war, France, unlike the United States, exercised its right to reparations on a large scale and in 1946 dismantled the second track between Horb and Tuttlingen that had been laid only a few years earlier.

At the same time, Deutsche Bundesbahn abandoned services at numerous stations on this section in order to increase travel speeds in local traffic through so-called "express train driving".

The following lines operate in local transport: With the timetable change in June 2020, Abellio Rail Baden-Württemberg took over the electrically-operated services between Plochingen and Tübingen.

Especially in the first few weeks after the start of operations, a lack of rolling stock and technical problems led to numerous train cancellations.

[9] In regional transport, between Plochingen and Bempflingen the tariff of the Verkehrs- und Tarifverbund Stuttgart (VVS), applies, from Bempflingen to Eyach that of the Verkehrsverbund Neckar-Alb-Donau (naldo), from Eyach to Horb that of the Verkehrs-Gemeinschaft Landkreis Freudenstadt (VGF), from Horb to Immendingen that of the Zweckverband Verkehrsverbund Schwarzwald-Baar-Heuberg (VVR).

Starting in Plochingen, regular freight traffic now operates from and to Wendlingen am Neckar (from there on to Oberlenningen), to and from Nürtingen (from there on to Neuffen) and to and from Metzingen (from there on via the Ermstalbahn to Dettingen an der Erms).

The site of the former Tübingen freight yard was largely cleared in 2015 and the tracks were removed, and the freed-up areas were subsequently developed.

[10] On one to two working days a week, the route is served in the mornings by a Hohenzollerische Landesbahn train running from the Tübingen freight yard to Eyach in order to carry scrap and timber towards Mengen.