Only in 1971 were they united into a single line as the central section connecting the stations Oktyabrskaya to Prospekt Mira was completed.

Presently, the Kaluzhsko-Rizhskaya line is the third busiest in the system with a passenger traffic rate of 1.015 million per day.

[1] It has a bi-directional length of 37.8 kilometres (23.5 mi), and a travel time of 56 minutes, typically it is coloured orange on Metro maps and numbered 6.

The Kaluzhsko-Rizhskaya line was the first one in Moscow to be built in the time of the new epoch, when contrary to the old time-consuming manual work that produced the most famous stations in the system the De-Stalinization policies of Nikita Khrushchev forced the modernisation and development of new saving techniques.

Already the first stations show a clear transition away from the Stalinist elements in architecture, where it is obvious how the original project was altered to make it simpler and aesthetic.

The original design was standardised to the point where stations differed only in the colour of marble on the pillars and the ceramic tiling patterns of the walls.

A rational combination of using deep-level shield tunnels and a sub-surface station pit allowed for this, and would become the most widely used technique in many ex-USSR metro systems.

Originally it was thought that the two radii could exist on their own and terminate at the ring; however, the dynamic passenger inflow immediately made the Metro planners realise the mistake.

To correct this, it was decided to link the radii to a diameter and relieve the ring by allowing several transfer points inside the circumference.

At four stations long, it extended past the Russian Botanical Gardens into the new northern districts of Babushkinsky and Medvedkovo.

A second entrance was added to VDNKh in 1997 and Akademicheskaya has had a restoration of its ceramic tiled walls replacing them with aluminium planes.