As the next generation of Trolley cars gears up to begin service on the UC San Diego Blue Line, officials with the San Diego Metropolitan Transit System (MTS) unveiled the first Siemens vehicle of the new Trolley series as part of a “Trolley Open House.” The new Trolley cars will enter service as part of the 5000 vehicles series, representing the third generation of modern, low-floor vehicles, which have been in operation on MTS’ light rail network since 2005.