Trains interoperate on both ends: more than half trains to the north-east with the East Japan Railway Company (JR East) Jōban Line beyond Ayase down to Toride; some to the south-west with the Odakyū Electric Railway Odawara Line beyond Yoyogi-Uehara down to Hon-Atsugi, and more trains than to Hon-Atsugi, to Karakida on Tama Line.
The 21.9 km main line serves the wards of Tokyo: Adachi, Arakawa, Bunkyō, Chiyoda, Minato and Shibuya; a short stretch of tunnel in Taitō with no station. A 2.1km branch line goes from Ayase to Kita-Ayase both in Adachi. The colour of the line shown on maps and signboards is dark green, and EMUs of Tokyo Metro proper are lined with the colour (see photograph). Station numbers carry the preceding letter C. Automatic Train Operation is used on the line between Ayase and Kita Ayase.
According to the Tokyo Metropolitan Bureau of Transportation, as of June 2009 the Chiyoda Line was the second most crowded subway line in Tokyo, at its peak running at 181% capacity between Machiya and Nishi-Nippori stations.
The Chiyoda Line was originally proposed in 1962 as a line from Setagaya to Matsudo, Chiba Prefecture: the initial name was Line 8. In 1964, the plan was changed slightly so that through service would be offered on the Jōban Line north of Tokyo, and the number was changed to Line 9.
The first stretch was opened on December 20, 1969 between Kita-Senju and Ōtemachi. The line was almost completed by October 10, 1972 when it reached Yoyogi-Kōen, although the 1 km section to Yoyogi-Uehara was not completed until March 31, 1978. The branch line to Kita-Ayase was opened on December 20, 1979.
From March 18, 2008, Odakyū Romancecar trains began to run from Kita-Senju to Hakone-Yumoto (on Hakone Tozan Line) and Karakida (on Odakyū Tama Line. Trains also run from/to Shin-Kiba using a connecting line between the Yūrakuchō Line and Chiyoda Line. It is the first time that reserved-seating trains have operated on a Japanese subway.
|Chiyoda Line route map|
Lines with transfer are of Tokyo Metro unless noted.
|Station||Distance (km)||Limited Express||Transfers||Location
(Ward in Tokyo)
|C-1||Yoyogi-uehara||0.0||(/*)||Odakyu Electric Railway: Odawara Line through trains||Shibuya|
|Kita-Ayase Branch Line|
Listed below are currently used, all are 10-car formations unless otherwise indicated. Numbers in parentheses are of formations currently in service.