Russia - Moscow - 14,4 km long 6 station extension to Line 15 (Nekrasovskaya Line) to the eastern suburbs of the city is opened on March 27. Line 15 is now 23,3 kilometre long and 10 stations.

What is special with this line is tunnel designers chose 10 metre diameter large boring tunnel which accommodates 2 tracks. In other lines there are two tubes, one track in each tube.

https://www.railwaygazette.com/metros/moscow-metros-line-15-completed/56143.article