The Rhine-Neckar S-Bahn forms the backbone of the urban rail transport network of the Rhine Neckar Area, including the cities of Mannheim, Heidelberg and Ludwigshafen.
The S-Bahn operates over 320 km of route in the states of Rhineland-Palatinate and Baden-Württemberg, and in small sections in Saarland and Hesse. S-bahn trains operate about 6 million kilometres per year, with 105 stations are served by 40 Class 425.2 Electric multiple units.
The S-Bahn is about 290 km long and is one of the largest S-Bahn networks in Germany. The core area is in the states of Rhineland-Palatinate and Baden-Württemberg. At Homburg (Saar), it touches the Saarland and it has three stations in Hesse between Neckarsteinach and Hirschhorn. Four of the six lines run together on the core Schifferstadt–Ludwigshafen–Mannheim–Heidelberg section, with five branches to Homburg, Osterburken, Karlsruhe, Germersheim and Eppingen.