Miniatur Wonderland Hamburg is the world's largest model train set as officially certified by the Guinness World Book of Records. Apparently the whole system is powered by software built in Delphi on the back end (including the control room). Embarcadero's Jim McKeeth has another article where he details more about the control room and the other software like Railware that controls the whole setup.
The train set has a 1,490 m² layout, contains 260,000+ figures, cost over 21 million Euro's to build, has 42 planes up in the air, has 9,250 cars, 1,040 trains, 1,380 signals, 385,000 LEDs, 4,110 buildings, 130,000 trees, a track length of 15,400 meters, and took over 760,000 hours to build.
This video is by the Guinness World Book of Records touring the facility including the control room and it's electric model car charging station.