Rail services in southern Hesse are focussed on the city of Frankfurt and are organised by the Rhein-Main-Verkehrsverbund ("Rhine-Main Transport Association"), while rail services in northern Hesse are focussed on the city of Kassel and are organised by the Nordhessischer Verkehrsverbund ("North Hesse Transport Association").
The Rhine-Main Transport Association has given unique numbers to its regional railway services in regular operation.
Rhine-Main S-Bahn lines have a single digit with an "S" prefix, as is standard in Germany, while the remaining lines have two-digit numbers, preceded by two letters indicating the train class: "RB" (Regionalbahn) and "RE" (Regional-Express).
Siemens Vectron (MRCE 193) + double deck coaches Stadler Flirt LINT (only HLB 25678 and 25679)
LINT (only HLB 25678 and 25679) Main-Spessart railway, Bamberg–Würzburg railwayWürzburg electric net 800, 810 Bombardier Talent 2 460 620 445 The following regional services are organised by the Nordhessischer Verkehrsverbund (North Hesse transport association): Bombardier Talent 2 (442) 30 (peak) 120 (Sat+Sun) The three services of the RegioTram Kassel are operated by the Regionalbahn Kassel GmbH (RBK) with two-system vehicles of the RegioCitadis class from Alstom.