Dortmund Stadtbahn, Light rail system in Dortmund, Germany

The Dortmund Stadtbahn is a light rail system operating eight lines throughout the city. The network combines underground tunnels beneath the city center with surface sections and serves more than 120 stations across different neighborhoods.

The first express tram section opened on 30 April 1959 from Markgrafenstraße via Westfalenpark to Hacheney, and the first underground station, Westfalenhalle, followed in 1967. Stadtbahn service began on 15 May 1976 on a 4.1 km section between Kirchderne and Grevel, initially run by tram line 2. The first longer tunnel opened in Hörde on 27 May 1983, and the system was officially inaugurated on 2 June 1984 with line U41.

The U-numbering follows a Rhine-Ruhr convention: U plus 4 for Dortmund, then a line digit, so U49 is a Dortmund line. The three central interchange stations Kampstraße, Reinoldikirche and Stadtgarten form a triangle under the pedestrian centre, and the control centre sits inside Stadtgarten station. Extra trains run only for matches at the Westfalenstadion or events at the Westfalenhallen.

Trains run every 10 minutes during the day, every 15 minutes on Sundays and from about 20:00, and every 20 minutes from start of service until about 5:00; the U49 drops to a 30-minute interval from about 22:00. At Hauptbahnhof, arriving U45 trains continue as U49. The U41 and U47 connect with bus 490 to Dortmund Airport.

The "U" prefix is not a line letter but a network marker: the digit after it is Dortmund's area code within the Rhine-Ruhr Stadtbahn, followed by the line number. So U49 means area 4, line 9. The system's control centre sits inside the underground Stadtgarten station, one of the three central crossing points.