The Mita Line (三田線 Mita-sen ) is a subway line of the Tokyo Metropolitan Bureau of Transportation (Toei) network in Tokyo, Japan. The line runs between Nishi-Takashimadaira in Itabashi and Meguro in Shinagawa. Trains often continues with direct service into the Meguro Line of Tokyu Corporation for Hiyoshi. The portion between Shirokane-Takanawa and Meguro is shared with the Tokyo Metro Namboku Line, possession of Tokyo Metro.
On maps and signboards, the line is shown in color "navy blue" ▉, and stations carry the letter "I" followed by two digit number. (M is for Marunouchi Line.)
Platforms on the Mita Line are equipped with automatic platform gate of chest-height barriers that open in sync with the train doors. The line was the first in the Tokyo subway system to have low barriers, while Marunouchi Line having erected them recently. The Namboku Line has installed full-height platform screen doors earlier since its opening.
According to the Tokyo Metropolitan Bureau of Transportation, as of June 2009 the Mita Line is the ninth most crowded subway line in Tokyo, running at 164% capacity between Nishi-Sugamo and Sugamo stations.
The Mita Line was first envisioned in 1957 as a northern branch of the Line 5 (present Tōzai Line) to serve the segment between Ōtemachi and Itabashi. Under a revised proposal in 1962, the line was made independent, and its construction undertaken by the Tokyo Metropolitan Government. The new line, numbered Line 6, was planned to run from Gotanda Station on the south-western side of the Yamanote Line through central Tokyo, with its northern extensions via Yamatochō (大和町) in Itabashi, near present Itabashi-honchō, diverting to Kami-Itabashi and Shimura (志村), present Takashimadaira. The southernmost portion from Sengakuji to Nishi-Magome, and Nishi-Magome depot was to be shared with the "Line 1" (Asakusa Line), therefore the Line 6 would be 1435 mm gauged.
Due to various political considerations, the design of the Mita Line changed several times in the early 1960s. There were plans for it to run to Toda, Saitama in order to serve a boat-racing venue for the 1964 Summer Olympics. The government of Saitama also proposed the construction of a new subway line which would allow through service on the Mita Line as far as Ōmiya Station.
In 1964, these plans were changed so that the Mita Line would connect to the Tōbu Tōjō Line via a branch line to be built by Tōbu from Yamatomachi (大和町) (present Wakōshi) to Shimura, the northern end of Line 6. To the southern end, connection to Tōkyū network would be made via a connecting line which would be constructed by Tōkyū from Sengakuji to Kirigaya (桐ヶ谷) on Ikegami Line, then the route would be to the then Den-en-toshi Line, finally west down to Nagatsuta. Thus the standards of Line 6 were based on those of Tōbu and Tōkyū, such as 1,067 mm gauge and 20 m cars. And a depot at Shimura, independent of Nishi-Magome depot on Line 1, be built.
But both Tōkyū and Tōbu decided the following year to operate their through services with the then Teito Rapid Transit Authority ("Eidan" or "TRTA", present Tokyo Metro) lines instead. With no through service opportunities available, the Tokyo Metropolitan Government commenced construction on the central portion of the line, leaving the plans for the Itabashi and Mita ends open for future development, requiring extension somewhere south of Seishōkō-mae (清正公前), present Shirokane-Takanawa, probably to the then Mekama Line of Tōkyū, which competed with TRTA Line 7, later named Namboku Line.
The first segment of the line opened on December 27, 1968, between Sugamo and Takashimadaira (10.4 km). The line was extended a further 7.3 km south to Hibiya on June 30, 1972, and 3.3 km further south to Mita on November 27, 1973. The northern 1.5 km extension, originally licensed to Tōbu, later transferred to Tokyo government, was completed on May 6, 1976. For the next 24 years, the line operated between Mita and Nishi-Takashimadaira; licensed Mita and Sengakuji section had been left uncompleted.
In 1985, the then Ministry of Transport finally settled the plan regarding the southern extension of the line, and shelved all plans for further extension to the north due to the development of the Saikyō Line. On September 26, 2000, the final 4 km segment from Mita to Meguro opened, and through service to the Meguro Line of Tōkyū began. The line switched to driver-only train operation at the same time.
The right-of-way and stations between Shirokane-Takanawa and Meguro are shared with the Namboku Line of Tokyo Metro. Under an agreement of both parties, the fare for this section is calculated on the Toei system for passengers traveling to stations on the Mita Line past Shirokane-Takanawa, on the Metro's for those who destines on the Namboku Line past Shirokane-Takanawa, and on the system "most beneficial to the passenger" (presently the Metro schedule) for travel solely on the shared section.
All stations are located in Tokyo. Stations I-22 through I-27 are surface or elevated.
|I-01||Meguro *1 目黒||Shinagawa|
|I-02||Shirokanedai *2 白金台||Tokyo Metro: Namboku Line||Minato|
|I-03||Shirokane-Takanawa *2 白金高輪||Tokyo Metro: Namboku Line|
|I-11||Suidōbashi 水道橋||JR East: Chūō-Sōbu Line local trains on Chūō Main Line||Bunkyō|
|I-15||Sugamo 巣鴨||JR East: Yamanote Line||Toshima|
|I-16||Nishi-Sugamo 西巣鴨||At Shin-Kōshinzuka|
All series are of 6-car sets unless otherwise noted.