The Gäubahn between Stuttgart Hauptbahnhof and Horb am Neckar set in the year 1985 would be a strong addition to Train Sim World. The route is around 80 km long, including the Verbindungsbahn, and features significant gradients, climbing roughly 200 meters within the Stuttgart urban area alone. Due to these elevation changes and the alignment along the hillsides, the line offers notable views over the Stuttgart basin and is often considered one of the most scenic inner-city railway lines in Germany.
The route begins at Stuttgart Hauptbahnhof and immediately climbs towards the Kräherwald, winding through the city to Stuttgart Westbahnhof. After a tunnel, it passes the Heslacher waterfall and continues towards Stuttgart-Österfeld. Between Österfeld and Stuttgart-Rohr, the line runs on a four-track section. From Stuttgart-Rohr, it continues southwest, passing between Böblingen and Herrenberg along the edge of the Schönbuch. The route then crosses the open Gäu landscape towards Eutingen im Gäu before descending into the Neckar valley towards Horb am Neckar, near the eastern foothills of the Black Forest.
The rolling stock for this route could include the VT 11.5 for TEE services, the BR 110 in ocean blue, the BR 140 in green “Knallfrosch” livery, and the BR 260 for shunting operations at Stuttgart Hauptbahnhof, Westbahnhof, and Vaihingen.
The BR 420 could be included as well, with the roughly 10 km long 'Verbindungsbahn' between Stuttgart Hauptbahnhof and Stuttgart-Österfeld, including stops at Schwabstraße, Feuersee, and Stadtmitte for S1 services to Böblingen
Additional variety could come from freight layers with the BR 194 and the BR 218, which would fit well with the operational profile of the line.