The trams were originally operated by the privately owned "Ulmer Straßenbahn- und Elektrizitätswerk" until being bought by the city on 1 April 1905.
[3] Expansion of the network began again in 2007 with the construction of a 4.6 km long extension from Donauhalle to Böfingen, which opened on 21 March 2009.
[3] The expansion continued with the opening of the new 9.8 km long line 2 on 8 December 2018, linking Science Park in the north-west of Ulm to Kuhberg in the south-west.
[2] The two lines share almost a kilometre of track in the city centre between Theater and Ehinger Tor, including the tram stop at the main railway station.
[2] Germany's highest tram stop is at Botanischer Garten (Botanical Gardens) on line 2, which is 617 m above sea level.