The Siemens–Duewag U2 is a type of light rail vehicle (LRV), built by consortium of Siemens, Duewag and Wegmann & Co built between 1968 and 1990. The design was based on the prototype U1 tram built in 1965 for the Frankfurt U-Bahn. The U2 was also designed for and used by the Frankfurt U-Bahn. The name is derived from the class identifier given to the cars in the Frankfurt. The U2 was later exported to North America and adapted for use on light rail systems in Edmonton, Calgary, and San Diego, during a period in which few purpose-built LRVs were being manufactured.