The Berlin U-Bahn (“underground railway”) is a rapid transit railway in Berlin:
– major part of the public transport system of the city
– opened in 1902
– the U-Bahn serves 170 stations
– spread across ten lines
– total track length of 151.7 kilometres, about 80% of which is underground
– trains run every two to five minutes during peak hours, every five minutes for the rest of the day
– trains travel 132 million km a year
– over 400 million passengers a year

The entire system is maintained and operated by the Berliner Verkehrsbetriebe, commonly known as the BVG.

Designed to alleviate traffic flowing into and out of central Berlin.