As the principal city of the Rhein-Main Region region and as the business capital of Germany, Frankfurt has a very extensive transportation network. There are a total of 9 “S-Bahn” lines, 9 “U-Bahn” lines, 9 tram lines, as well as a bus network. The Frankfurt Hauptbahnhof is one of the largest in Germany. Public transit in the Frankfurt area is overseen by the Rhein-Main-Verkehrsverbund. Within Frankfurt itself, most services are operated by Stadtwerke Verkehrsgesellschaft Frankfurt am Main (VGF).