Line 5559 would run from Freising station as a four-track line together with line 5500 (the
Munich–Regensburg railway) to Neufahrn North junction (
Abzweig Neufahrn-Nord). It would run over the "Neufahrn counter curve" (
Neufahrner Gegenkurve) to reach line 5557 (the
Neufahrn Link) at Neufahrn East junction (
Abzweig Neufahrn-Ost) and connect with line 5556 (
Munich East–Munich Airport railway) at Airport West junction (
Abzweig Flughafen-West). From there the existing double-track line would be shared through the airport. The route from Freising to Munich Airport is long. The route would continue under the eastern apron of Munich Airport in a tunnel until it resurfaces near Schwaigerloh. It would then run above ground to Erding. In the Schweigerloh area it is intended to build a system for turning trains, so trains coming from
Regensburg or
Landshut to stop at the airport could be reversed. After another a junction station would be built on the grounds of the
Erding Air Base that can accommodate both
Munich S-Bahn trains and regional trains from the southeast using the “Walpertskirchen link” (
Walpertskirchener Spange). The current station in the centre of Erding, which is 700 metres away, would then be closed. Trains would continue towards Munich on the existing
Markt Schwaben–Erding railway. The section between the Altenerding station and the current Erding Station would be tunneled or lowered in order to avoid congestion at two level crossings (Haager Straße and Dorfener Straße). The resulting open space is planned to be redeveloped as residential and green areas.
"Neufahrn counter curve" (Neufahrner Gegenkurve) , March 2017 The main construction work began in early October 2014. The line opened in late 2018 with regular train services commencing in December 2018. ==Planning==