The Austrian capital boasts an efficient infrastructure and a comprehensive organization that few other cities offer. The public transportation network proves to be a better alternative than the city's heavy car traffic, especially in more central areas, where parking is not only hard to find, but also rather expensive. Here are the four main components of the public transportation system
Underground
The underground system, referred to as the U-Bahn, is made up of five lines and covers a great deal of the city. To avoid confusion, each of the five lines serves a particular area and is painted in a different color, as follows: U1 is the red line, U2 is the purple line, U3 is the orange line, U4 is the green line, U5 is surprisingly missing, and U6 is the brown line. This way of getting around is perhaps the locals` favorite, being fast and reliable. You probably won't have to wait at the station for more than ten minutes. Just like buses and streetcars, subway lines operate from 5:00 a.m. to 12:30 at night.
Streetcars
Streetcars, or trams, are another traditional means of transport in Vienna. The network is comprised of 600 vehicles over 31 individual lines. They are concentrated mainly in the central areas, and do not go to the remotest neighborhoods, but still serve a rather large part of the city. In most cases, the streetcars run much more frequently than buses.
Bus
Generally speaking, buses in Vienna are there to cover the gaps left by the subway, but not exclusively. There are 59 daytime lines and 21 night lines, served by 500 vehicles. What you need to know is that all tickets and passes entitle you to use all kinds of public transport, including underground, streetcars and buses, with the exception of night buses. A special ticket needs to be purchased for those, in addition to your regular ticket or pass. Be careful, as the number of people fined on night buses is substantially larger than those fined during the day. Also bear in mind that if you get caught without a valid ticket, you will be taken to the nearest police station and you will have to pay a penalty fare of 62 Euro, which is much more than a monthly transport pass would cost (45 Euro). Ticket inspectors wear plain clothes instead of uniforms.
A single ride ticket can be obtained at any station, and in most tobacco shops; it costs 1.50 Euro and gives you the right to use the three forms of transport mentioned above, and to change vehicles as often as you have to within the following hour. When purchased onboard the bus, tram or subway (from a ticket machine or straight from the driver), tickets cost 2 Euro. If you have bought your ticket in advance, it needs to be validated using one of the blue machines at bus, tram and underground stations, but those purchased from the driver needn't be stamped. Daily, three-day, weekly, monthly and annual passes must be purchased in advance.
Commuter Trains
There's just a dozen commuter trains running in Vienna, but this is a very convenient way of traveling between the Vienna International Airport and the city center (line S7), but most people would not recommend them for reaching other destinations in Austria.
Exploring the City on Foot
Since the most important sights are situated close to one another within the inner city, touring around Vienna on foot is a pleasant alternative to motorized transport; the best part of all is that it's free!