In accordance to the Technical and economic report on the metro ratified by the Council of Ministers of Bulgaria and the approved General City Plan, the General scheme for the development of the lines should consist of three diameters with extensions in the periphery, with total length of 75 km, 69 metro stations (with possibility to reach 80 km in long term perspective and to carry 1,2 million passengers daily at the final stage of implementation).
FIRST METRO DIAMETER (LINE 1)
“Lyulin RD – Centre – Mladost RD – Druzhba RD – Sofia Airport” will be 32 km long with 26 stations.
SECOND METRO DIAMETER (LINE 2)
"Lozenets RD - Centre - Nadezhda RD - Obelya RD" will be 22 km long with 22 stations.
THIRD METRO DIAMETER (LINE 3)
"Ovcha Kupel RD - Centre - V. Levski RD" will be 21 km long with 21 stations.
The diameters intersect into a triangle in the city center, thus each section of the metro route could be reached within one single interchange of the line.