Siemens Mobility's modern Inspiro trains and Communications Based Train Control (CBTC) Trainguard MT (TGMT) systems have gone into passenger service today on Line 3 of the Sofia Metro. The trains and systems will serve the third metro line of the Bulgarian capital, which was opened today in the presence of the Minister of Transport Rosen Zhelyazkov, the Mayor of Sofia Mrs. Yordanka Fandakova and the Executive Director of "Metropoliten" EAD Prof. Dr. Stoyan Bratoev.