Until recently, trams of type TMK2100 were active only on line 5 and sometimes on line 9. Only half of the TMK 2100 fleet is technically correct. Recently KT4YU trams in Trešnjevka depot have serious technical problems, which leads to a lack of vehicles. So now we can see TMK 2100 on lines 5,9,12,17 / TMK 210 on lines 2 and 3 (which is very unusual) and TMK 2200 on all lines from Trešnjevka depot.