While there are no plans to build entirely new railway lines to add to the S-Bahn network, plans exist to upgrade and convert some existing lines to S-Bahn standards. In the past some extensions of S-Bahn service have simply been "relabeling" of an existing service such as
S5 which was previously known as the "
Allersberg Express". Indeed, no S-Bahn runs on an entirely new line, but in some cases the existing lines were extended, electrified or amplified for the introduction of S-Bahn service.
Towards Würzburg Plans include S-Bahn service along the
Fürth Würzburg line which is currently one of the busiest lines in the region. In the course of
Deutschlandtakt plans, a newly built high speed line is planned to enable travel times below 30 minutes between Nuremberg and Würzburg for high speed trains. This would free up capacity on the legacy alignment for more frequent service and the introduction of a "true" S-Bahn. Similar to the December 2020 switchover on "S5", there are plans to convert existing regional train service to Neustadt (Aisch) to a new "S6" with the December 2021 or the December 2022 schedule change. No changes in service pattern or additional infill stations are planned for that switchover. In late September 2021 it was announced that the new Nuremberg-Würzburg high speed line which is to include a tunnel from Nuremberg to
:de:Bislohe, a neighborhood annexed to Fürth in 1972, was reclassified, together with other parts of the "Deutschlandtakt" concept into the highest priority group "vordringlicher Bedarf“. The new high speed line would free up capacity on existing infrastructure allowing S-Bahn service with better frequencies.
Towards Markt Erlbach and Cadolzburg The branch lines to Cadolzburg (
Rangau Railway) and Markt Erlbach (
Zenn Valley Railway) are currently not
electrified and electrification is often seen as precondition for S-Bahn service along those lines. Other proposals call for the use of hydrogen powered trains or
battery electric trains to replace existing
diesel multiple units.
Towards Gräfenberg There are also plans to use the (largely extant but not used for passenger service)
Nuremberg Ringbahn to integrate the
Gräfenberg railway (which currently terminates at
Nuremberg Nordost station along the Ringbahn) into the S-Bahn network. One of several proposals calls for the linking of the aforementioned lines to Cadolzburg and Markt Erlbach via the Ringbahn. However, such plans have repeatedly failed to reach the required benefit cost ratio above 1.0.
Towards Crailsheim In December 2020 the ministers of transportation for Baden Württemberg and Bayern announced their intention to extend the S4 from its current endpoint at Dombühl across the state line to Crailsheim with a proposed entry into service 2024. This extension opened as planned with the December 2024 schedule change.
Towards Neuhaus (Pegnitz) and Simmelsdorf-Hüttenbach In the course of the planned electrification of the
Nuremberg Cheb railway there are also plans to establish S-Bahn service along this line. In the course of this expansion it is also planned to offer S-Bahn service along the branch line to Simmelsdorf-Hüttenbach (
Schnaittach Valley Railway) In April 2021 a planning agreement between the State of Bavaria and Deutsche Bahn concerning the planning of S-Bahn service along the (to be electrified)
right Pegnitz railway and the
Schnaittach Valley Railway was signed. In the course of S-Bahn expansion, two new infill stations are planned:
Hersbruck-East and "Eschenbach" in the borough of
Pommelsbrunn of that name.
Towards Hilpoltstein Local politicians repeatedly demand to electrify the 11 km of the
Roth Greding railway currently still in service and to extend S-Bahn service currently terminating in Roth along that line. A further precondition for S-Bahn service besides electrification is the upgrade or removal of at least some of the 22 level crossings along that line. A
feasibility study ordered by the city of
Hilpoltstein was released in 2020. Costs for the necessary electrification and associated upgrades to allow speeds up to 80 km/h (instead of the current 60 km/h speed limit) were given as 24 million € in 2020. In 2021 local farmers raised objections to the proposed closure of several level crossings as they were their principal users.
Infill stations Throughout the history of the S-Bahn, there have been a number of
infill stations built along existing right of way to better serve certain areas. There are plans for a couple of infill stations, among them "Neumarkt Süd" (S3) "Bamberg Süd" (S1) and "Forchheim Nord" (S1) == Interchanges with other systems ==