The capital of the German federal state Baden-Wuerttemberg (about 600,000 inhabitants) has a large light rail network with a system lenght of approx. 130 km. It is mainly running on converted former metre-gauge tramway routes. As part of the rebuild, the tracks were largely separated from road traffic, partly by buildingunderground sections, and the track curves became larger radiuses. The changeover from tramway to light rail began in 1985 with the U3 and was finished at the end of 2007 with the replacement of the tram line 15 by the light rail line U15.
In addition to the light rail routes, there are also two exotics in Stuttgart's public transport: the cogwheel railway from Marienplatz to Degerloch (called "Zacke", line 10) and the funicular from Südheimer Platz to Waldfriedhof. The funicular is integrated into the fare system as line No. 20.
All three rail systems and the city buses are operated by → Stuttgarter Straßenbahnen AG (SSB)