Tokyo Metro Chiyoda Line

The Tokyo Metro Chiyoda Line (東京メトロ千代田線) is a subway line owned and operated by Tokyo Metro in Tokyo, Japan. On average, the line carries 1,447,730 passengers daily (2017), the second highest of the Tokyo Metro network, behind the Tozai Line (1,642,378).

The line was named after the Chiyoda ward, under which it passes. On maps, diagrams and signboards, the line is shown using the color green, and its stations are given numbers using the letter "C".

Overview
The 24.0 km line serves the wards of Adachi, Arakawa, Bunkyō, Chiyoda, Minato and Shibuya, and a short stretch of tunnel in Taitō with no station. Its official name, rarely used, is Line 9 Chiyoda Line (9号線千代田線). The Chiyoda Line was built as a bypass for the older Hibiya Line, with both lines following a similar route and having direct interchanges at three stations. Trains have through running onto other railway lines on both ends. More than half of these are trains to the northeast beyond Ayase onto the East Japan Railway Company (JR East) Joban Line to Toride. The rest run to the southwest beyond Yoyogi-Uehara onto the Odakyu Odawara Line to Isehara.

The Chiyoda Line has direct interchanges with all other Tokyo Metro and Toei lines with the exception of the Toei Oedo Line. However, Yushima Station is located relatively close to Ueno-okachimachi Station on the Oedo Line without being marked as an official transfer between the lines.

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.

Basic data

 * Distance: 24.0 km
 * Double-tracking: Entire line
 * Railway signalling: New CS-ATC

Station list

 * All stations are located in Tokyo.
 * Stopping patterns:
 * Commuter Semi Express, Local, Semi Express, and Express trains stop at every station.
 * Odakyu Romancecar limited express services stop at stations marked "●" and does not stop at those marked "｜".

Rolling stock
, the following train types are used on the line, all running as ten-car formations unless otherwise indicated.

Tokyo Metro

 * 16000 series (x37) (since November 2010)
 * 05 series 3-car trains (x4) (since April 2014, used on Kita-Ayase Branch)

Odakyu

 * 4000 series (since September 2007)
 * 60000 series MSE (since spring 2008)

JR East

 * E233-2000 series (x19) (since summer 2009)

Former rolling stock

 * 6000 series (x35) (from 1971 until November 2018)
 * JNR 103-1000 series (x16) (from 1971 until April 1986)
 * JR East 203 series (x17) (from August 27, 1982 until September 26, 2011)
 * JR East 209-1000 series (x2) (from 1999 until October 13, 2018)
 * JNR 207–900 series (x1) (from 1986 until December 2009)
 * 5000 series 3-car trains (x2) (from 1969 until 2014, later used on branch line)
 * 6000 series 3-car train (x1) (prototype of the series built in 1968 until 2014, used on branch line)
 * 06 series (x1) (from 1993 until January 2015)
 * 07 series (x1) (September 2008 – December 2008)
 * Odakyu 1000 series (1988–2010)
 * Odakyu 9000 series (1978–1990)

History
The Chiyoda Line was originally proposed in 1962 as a line from Setagaya in Tokyo to Matsudo, Chiba; the initial name was "Line 8". In 1964, the plan was changed slightly so that through service would be offered on the Joban Line north of Tokyo, and the number was changed to "Line 9".

Line 9 was designed to pass through built-up areas in Chiyoda, and also intended to relieve the busy Ginza Line and Hibiya Line, which follow a roughly similar route through central Tokyo. 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. This branch primarily serves as a connection to Ayase Depot, but also serves Kita-Ayase Station constructed in the area. A three-car shuttle service operates between Ayase and Kita-Ayase.

The Chiyoda Line was one of the lines targeted in the Aum sarin gas attack on March 20, 1995.

On May 15, 2006, women-only cars were introduced on early-morning trains from Toride on the Joban Line to Yoyogi-Uehara.

On March 18, 2008, the Chiyoda Line became the first subway line in Japan with operations by reserved-seating trains when Odakyu Romancecar limited express services began running between Kita-Senju and Hakone-Yumoto (on the Hakone Tozan Line) and Karakida (on the Odakyu Tama Line). Trains also run from/to Shin-Kiba using tracks connecting to the Yurakucho Line.

On March 16, 2019, 10 car services to Kita-Ayase station commenced.