Today the line features a combination of stations that were built during different periods and some rebuilt since. Also it is one of the busiest in the system and for some stations, that are almost 70 years old clearly show their age. Improvement works have been carried out several times throughout history, but in recent times their emphasis has grown. Belorusskaya was recently subjected to an extensive facelift reconstruction on replacement of its old ceramic walls with new marble ones. The world famous Mayakovskaya station following the opening of the second exit in 2005 had its original vestibule closed for replacement of escalators. It is expected that additional reconstruction will be done on 1960s "centepede" stations including the replacement of old ceramic tiles with aluminium planes.