local economy. In 2007, 45% of the people working in downtown Calgary took transit to work; the city's objective is to increase that to 60%. Rolling stock The system initially used Siemens-Duewag U2 DC LRVs (originally designed for German metros), and used by the Frankfurt U-Bahn. The slightly earlier Edmonton Light Rail Transit, and the slightly later San Diego Trolley were built at approximately the same time and used the same commercial off-the-shelf German LRVs rather than custom-designed vehicles such as were used on the Toronto streetcar system and the Vancouver SkyTrain. U2 vehicles constituted the entire fleet in Calgary until July 2001, when the first Siemens SD-160 cars were delivered. Eighty-three U2 DCs were delivered to Calgary over three separate orders; 27 in 1981, three in 1983, and 53 in 1984 and are numbered 2001–2083. As of March 2020, 39 out of the original 83 U2 DCs remain in service, plus car 2090. The success of the first North American LRT systems inspired Siemens to build an LRV plant in Florin, California. Siemens now supplies one-third of North American LRVs and has supplied over 1000 vehicles to 17 North American systems. This will include 258 vehicles for Calgary when the current order of Siemens S200 vehicles is completed. The following LRVs have been retired: Note: units in parentheses in the first row in the above table were retired at end of life, but are also listed in rows below. In 1988, the Alberta Government purchased from Siemens two U2 AC units, the first of their kind in North America, for trials on both the Edmonton and Calgary LRT systems. The cars were originally numbered 3001 and 3002 and served in Edmonton from 1988 to spring 1990. These LRVs came to Calgary in the summer of 1990 and in September, Calgary Transit decided to purchase the cars from the province and then applied the CT livery to the cars (they were previously plain white in both Edmonton and Calgary). They retained their original fleet numbers of 3001 and 3002 until 1999, when CT renumbered the cars 2101 and 2102. Initially, these two cars were only run together as a two-car consist as they were incompatible with the U2 DCs. In 2003, Calgary Transit made the two U2 ACs compatible as slave cars between two SD-160s and have been running them like this ever since. In July 2001, Calgary Transit brought