Line S1 is a line on the Munich S-Bahn network. It is operated by DB Regio Bayern. It runs from Munich Airport station and Freising to Neufahrn bei Freising station, where most trains are coupled (and uncoupled in the opposite direction). Trains continue via Feldmoching, Laim, central Munich to Munich East.
The line is operated at 20 minute intervals between Munich Airport station and East Munich. Two out of three trains an hour continue from Neufahrn bei Freising to Freising, so that the gap between trains alternates between 20 and 40 minutes. It is operated using class 423 four-car electrical multiple units, usually as two coupled sets. In the evenings and on Sundays they generally run as single sets.
The line runs over lines built at various times:
S-Bahn services commenced on 28 May 1972 as S-Bahn line S 1 between Freising and Kreuzstraße. Line S 7 took over the section from Munich East to Kreuzstraße on 10 June 2001. Services to Munich Airport commenced on 29 November 1998.