Vienna as the capital of Austria has often been considered one of the best cities in the world to live in. Reasons for this are versatile: Low social conflict, cultural experience, a well-maintained natural environment, and last but not least an extensive system of public transport maintained by the Wiener Linien, the eponymous Lines of Vienna.
Cue some Early-Installment Weirdness however, even if Vienna features a comparably young subway system because it's actually Older Than They Think as its precedessor was the Stadtbahn opened in 1898 and built with heavy rail perimeters. Those parts that would much later turn into subway lines (U4 and U6) were given to the city of Vienna in 1924 and got thoroughly electrified and put into service as a light rail in 1925, complete with a fare union with the tramway, that one part that wouldn't (the Vorortelinie in the northwest) became the S45 run by the ÖBB.
Vienna is also famous for its €365 ticket. As a year has 365 days, this means that you can ride all the lines in Vienna for €1 per day. It's also the base model for the 1-2-3 ticket that's being introduced by the ÖBB: €3 per day for the entirety of Austria, €2 per day for two neighboring states and €1 for one state. Lower Austria (Rural) and Vienna (Urban) count as one state here for practical reasons. In 2021, only the first phase with €3 for all of Austria is already available.
The S-Bahn
Vienna has also had an inner-city underground railroad link since 1873 with an overground predecessor from 1859 on, but it's only been used for S-Bahn-typical crossrail services since 1962, first as the Schnellbahn (rapid rail) and from 2005 as S-Bahn as anywhere else. It proved to be an even better subway after Vienna's Imperial Bridge collapsed early in the morning without warning at August 1st, 1976, running on a 7½-minute headway that was doubled at rush hour. It touches the edges of Central Vienna (defined as the pocket between modern-day U6 and U4) at its east and south and the southern part became handy when Vienna Central Station was built: As it was built in the bend of the former cargo terminal between Southern Main Line and Eastern Main Line which already demanded a closure to Vienna South Station (a double terminal with a common lobby), the westernmost station Wien Meidling became the provisional terminal of the Southern Main Line and only the Eastern Main Linie needed a provisional terminal called South Station (East).
As the former cargo terminal that was transformed into a main station was already at South Tyrol Square which already had a stop for the S-Bahn and the U1, rapid transit was already handy and existent, yet there are proposals to extend the future U5 from Karlsplatz down south to Hauptbahnhof, however, due to fear of overcrowding instead of southeast. Former South Station was turned into a new neighborhood called Quartier Belvedere after neighboring Belvedere Castle that made the natural end point of the original South and East stations of Vienna. The Western Main Line received a new tunnel for direct access to Wien Meidling and therefore the new central railway station, leaving Vienna West Station as a mere regional hub with some S lines actually ending there after having been the most important intercity station for felt eternity.
The color of the S-Bahn logo in Vienna, but also everywhere in Austria, is usually blue, yet there's been a differentiation in color designations in the recent years to emphasize the difference between lifelines of dense headways from the rest. Said crossrail (the Stammstrecke) is depicted in pink whereas the tangential Vorortelinie in northwestern Vienna (S45) is depicted in mustard yellow. Said S45 is supposed to be merged with the southern tangential Verbindungsbahn (S80) to become a run-up for a ring line of the S-Bahn but requiring the merger with the remaining gap of the Donauuferbahn between Handelskai and Praterkai in the 2020s.
The U-Bahn
Digging and conversion for the U-Bahn started in 1969, grand opening was in 1978. There's a logic behind its numeration: Wholly new lines starting with U1 have odd numbers whereas lines on converted legacy structures have even numbers, creating the infamous U5 gap in a six-line scheme that's in the process to be closed. It's no accident that Stephansdom is crossed by U1 and U3 as the legacy lines didn't touch it. After multiple extensions into all directions into the 2010s, the program into the 2020s mostly constitutes of the Line Crossing U2xU5 where the maiden part of the U2 is split at City Hall and extended into both directions (new south branch of the U2, new north branch for the nascent U5). It's expected that Vienna will have 2 million inhabitants in 2030 and this measure equals the creation of a new trunk line in effect raising the number of interchange station in the combinding U-Bahn and S-Bahn network of Vienna from 10 to 14.
- The network started with the north-south running U1 (color red), the only really new subway line for a long time to come. New stretches were opened quickly and reached the right bank of the Danube River in 1982, crossing the river via the reconstructed Imperial Bridge. 2006 saw its last extensions. The U1 has accessed South Tyrol Square long before the new central railway station nearby was built that could take U-Bahn access for granted.
- The southwest-northeast U2 (color violet) started as a tram tunnel in 1966 for tram lines E 2, G 2 and H 2 which the modern line owes its number. It was converted to an U-Bahn line in 1980, connecting with U4 at both ends to form a circle around the central city. An eastward extension in 2008 to the football stadium doubled the length of the line, and in 2010 it became the third U-Bahn line to bridge the Danube.note A maiden part is in the process of being broken off as a new line U5 with an alternate southwest extension of U2 due to open in 2026-28, both U2 and U5 running on said maiden part in the interim. The completion of U2 to Seestadt Aspern (new settlement at interwar airport) in 2013 means that students from the local dormitories can take a direct ride to their universities as most of them are near a U2 station in central Vienna.
- An east-west U3 (color orange) line was built from 1991 to 2000. It became the third heavy rail line for both West Station and Wien-Mitte (Landstraße), connecting both to the city center and Simmering where ÖBB night trains find their home.
- The modern U4 (color dark green) developed from the outer knee of the former Stadtbahn which was converted from light rail to subway standards form 1976 and 1981 for that matter and still features many Belle Epoque stations from the start, most notably the Hietzing station near Schönbrunn Castle.
- The U5 (color teal) doesn't exist yet, but parts of the central loop of the U2 line (Rathaus in the northwest to Karlsplatz in the southeast) will be broken off from it in order to be extended into the northwest, crossing its former mother line at City Hall and due to open in 2024-26 as the first fully automatic line with platform screen doors. The U5 will share its tracks with the U2 until the latter gets its own extension. To continue with the students along the U2, the extension that will make the U5 will connect to local med school and the old and new AKH (General Hospital).
- The U6 (color brown) developed from the north-south Belt Line of the former Stadtbahn, starting in 1989 and finishing in 1996. The southern extension was originally built as a light rail line in the late 1970s. Because the central section is an architectually significant viaduct designed in the Jugendstil era by Otto Wagner, it couldn't be upgraded to full U-Bahn standard and is still operated by tram-like vehicles with overhead wire.
Tramway and buses
Vienna employs one of the most extensive tramway systems in the world, actually #5 behind the likes of Melbourne, Saint Peterburg, Berlin and Moscow. Just as the coat of arms of Vienna save for its white cross, streetcars and buses have a red livery. The network is so extensive that Vienna had the idea to make its new electric buses recharge via the tramway's overhead wire as if they were trolleybuses. The buses may therefore not have an extensive scope into the countryside, but it'll do for the inner-city where recharge options should always be handy.
Websites
Official Wiener Linien Site (English version)
