That was absolutely the correct information at the time I wrote that, based on publicly available information. Today İstanbul is building more metro lines simultaneously than any other city on earth, and since 2019, has opened about 100km of rail lines. (76km Marmaray rennovations, 18km M7, 4km M9, 10km T5) the railway system is about 250km long today.
https://en.wikipedia.org/wiki/Istanbul_Metro This shows all the metro lines under construction, and doesn't include in it's overall length at the top, the light rail (40km) and the TCDD metro (Marmaray - 76km)
https://www.youtube.com/watch?v=l_w-QJxJn2k - this guy tracks all the metro projects, you don't really need to understand what he's saying, just look at the graphics :)
