from the combined interlining of the multiple branches. A good example of this is the Berliner Stadtbahn in the Berlin's S-Bahn, which is regarded as a tourist attraction. However, in more lightly used sections outside the city centre, S-Bahn services commonly share tracks with other trains. Further out from the central parts of a city the individual services branch off into lines where the distances between stations can exceed 5 km, similar to commuter rail. This allows the S-Bahn to serve a dual transport purpose: local transport within a city centre and suburban transport between central boroughs of larger cities, and to suburbs. Frequencies vary wildly between systems with short headways in the core sections of large networks to headways of over 20 minutes in remote sections of the network, late at night and/or on Sundays and in smaller systems. The rolling stock typically used for S-Bahn systems reflects its hybrid purpose. The interior is designed for short journeys with provision for standing passengers but may have more space allocated to larger and more numerous seats. Integration with other local transport for ticketing, connectivity and easy interchange between lines or other systems like metros is typical for the S-Bahn. Where both S-Bahn and metro exist, the number of interchange stations between the two systems is substantial with metro tickets being valid on S-Bahn services, and vice versa. The S-Bahn Mitteldeutschland constitutes the main local railway system for Leipzig but also connects to Halle, where a few stations are located. The Rostock S-Bahn is an example of a smaller S-Bahn system. Etymology Germany, Austria and Switzerland The name S-Bahn is an abbreviation for the German "Stadtschnellbahn" (meaning "city rapid railway") and was introduced in December 1930 in Berlin. The name was introduced at the time of the reconstruction of the suburban commuter train tracks— the first section to be electrified was a section of the Berlin–Stettin railway from Berlin Nordbahnhof to Bernau bei Berlin station in 1924, leading to the formation of the Berlin S-Bahn. The main line Berliner Stadtbahn (English: City railway of Berlin) was electrified with a 750 volt third rail in 1928 (some steam trains ran until 1929) and the circle line Berliner Ringbahn was electrified in 1929. The electrification continued on the radial suburban railway tracks along with changing the timetable of the train system into a rapid transit model with no more than 20 minutes headway