In order to be able to build an underground line, Wiener Linien needs a construction and operating permit under Austrian railway law.
It must be demonstrated that the planned line is in the public interest.
Wiener Verkehrsbetriebe (Wiener Linien’s predecessor) was granted the first permits in 1968. These related to the U1 (from Reumannplatz to Praterstern), the U2 (converting the underground tram line from Karlsplatz to Rathaus into an underground train line) and the U4 (converting the Stadtbahn along the Wiental and Donaukanal lines).
These permits are valid for over 90 years.
Vienna’s underground logo