- a very short section of the Outer ring, opened in 1951 and electrified in 1983,
- a short section of the former Outer freight ring opened in the early 1940s and electrified in 1983,
- the Görlitz line, opened in 1866 and electrified in 1929,
- the Ring line, completed in 1877 and electrified in 1926 and, via a connecting curve,
- the east-west railway through central Berlin: the Berlin–Wrocław railway, which at Berlin Ostbahnhof becomes the Berlin Stadtbahn.
|Rolling stock||DBAG Class 481|
|Electrification||750 V DC Third rail|
A southern extension from Schönefeld station, serving the new Berlin Brandenburg International airport, is expected to open in 2018 or 2019. It will include two new stops: Waßmannsdorf and Berlin Brandenburg Airport (terminal). The line has already been built and is served by a few non-revenue trains, but the airport has not yet opened, thus delaying train service as well.
- "S-Bahn Network Map" (pdf). S-Bahn Berlin GmbH. 27 June 2008. Retrieved 4 June 2010.
- "Pannen-Flughafen BER: Eröffnung rückt in immer weitere Ferne" [Defective BER Airport: opening moves further and further away]. Focus (in German). 22 November 2014. Retrieved 25 December 2014.
- Map of the reorganization of the rail system serving the new airport "Berlin Brandenburg"
- "Infos and map". S-Bahn Berlin GMBH (in German). Archived from the original on 10 November 2013.