12th & Imperial Transit Center is the most complicated San Diego Trolley Station and the location of their main train yard viewable from the station platforms and an overpass near the station and is just south of downtown. The station first opened for the Blue Line with the original service segment on July 26, 1981, the East (now called Orange Line) arrived on March 23, 1986. The Waterfront extension to serve the Convention Center forming the loop around downtown opened on June 30, 1990. Until routings were reconfigured on September 2, 2012 the station was served by the Orange Line twice as it arrives from Gillespie Field and then terminates after passing through downtown luckily on clearly separate platforms. On that date the Blue and Orange Lines were pushed back to America Plaza and Santa Fe Depot Respectively with the Green Line extended south from Old Town along the Waterfront Route and now terminates at 12th & Imperial on the former Orange Line terminal platform making this station an important transfer point served by all 3 trolley lines.
The main 3 tracks of the station are surrounded by 4 platforms so every train opens its doors on both sides (and the requirements of ADA compliancy). These platforms have the station's bus loop just east of them and have a modern, about 12 story building built directly over the platforms with a separate clock tower of a taller height. These buildings serve as the corporate headquarters of the Metropolitan Transit System, the Operator of the San Diego Trolley. There is also a parking garage that has a similar design. The two eastern tracks are used by the Blue and Orange Line Trains only stopping intermediately on their way to pass through downtown, the third track beneath the building is unused. Green Line trains could stop at this platform but for better train yard access (and to avoid confusion) trains stop on their own platform with a few odd bus stop shelters (with white red lined roofs) just west of the station, on the north side of the train yard. This same platform (seperate from the through platforms into downtown is where Orange Line terminated when it made the around downtown loop).
Photo 1-3 taken on 15 March, 2008; Photos 4-22 taken on 20 March, 2011; 23 on 22 June, 2013