Since the commissioning of the Zürich S-Bahn in May 1990, the Hauptbahnhof has been the central node of the Zürich S-Bahn Stammnetz (core network). As such, it is the nodal point where S-Bahn lines S2, S3, S5, S6, S7, S8, S9, S12, S14, S15, S16, S19, S20, S21, S24 and S25, the Sihltal Zürich Uetliberg Bahn (S4 and S10) and Zürich trams interconnect.