Stuttgart’s transportation network is operated by Stuttgarter Straßenbahnen AG (SSB) within the city; SSB operates bus lines, light rail (Stadtbahn) lines, a cog railway, and a funicular. The region’s transportation network is overseen by Verkehrs- und Tarifverbund Stuttgart (VVS).
The Stuttgart Stadtbahn began service on September 28, 1985. Over the course of 27 years culminating in December 2007, the system was converted from a meter gauge to standard gauge. The system runs underground in the center of Stuttgart but it is not considered to be a u-bahn as in other cities.