New York City Subway It is the most complex network in the world with 472 active stations serving 27 subway lines. Until 1940, no official map of the subway system existed. The most influential map was made by graphic designer Massimo Vignelli in 1972.

Determining the "most complicated" transit system depends on how you measure complexity, but the Tokyo Rail Network is widely considered the top contender. It is a staggering labyrinth of over 100 lines managed by dozens of different private and public companies (including JR East, Tokyo Metro, and Toei Subway) that often require separate tickets or complex transfers. The sheer volume of over 800 stations and the density of the map can be overwhelming for newcomers. Another candidate is the New York City Subway, which is the largest by number of stations (472) and features a complex 24-hour schedule with express and local tracks that frequently change due to maintenance. Seoul's Metropolitan Subway is also cited for its massive length and multi-layered underground plazas. In 2026, the Beijing Subway is the longest in terms of track length, but Tokyo remains the gold standard for "complexity" due to the fragmented nature of its operators and the incredible precision required to navigate its interlocking schedules.