The TOEI system is run by the municipal
government and has 4 lines.
The Tokyo Metro has 9 lines and is
a consortium of railroads and governments.
The two systems do have
interchanges, but have different fare
structures. A PASMO or SUICA Farecard is the way to go. To transfer you must
tap your Farecard to exit one system followed by entering it another turnstile to
enter the other. Both systems are working on expanding their lines.
The
Toei O-Edo Line is the biggest expansion forming a ring around Tokyo to
provide some relief for the JR Yamanote Line, and the new Metro
Fukutoshin line parallels the Yamanote line, also providing some relief.
