The Teito Rapid Transit Authority, better known with it’s acronym of TRTA or by the “Eidan” nickname was the the foremost subway operator in Tokyo until it’s restructuration in 2004.
It was founded in 1941, during the war, as a government-ordered merger between the Tokyo Underground Railway and the Tokyo Rapid Railway companies (the latter was tied to the predecessor of today’s Tokyu Corporation), the two companies operating the Ginza Line, wich at the time was the sole subway line in Tokyo.
In the 1950s, as part of the post-war reconstruction works, TRTA opened the Marunouchi Line, Tokyo’s second subway line and the first line opened after the war. Another line, the Hibiya Line, was opened just before the 1964 Olympics.
From the mid-60s onwards, Tokyo and Japan as a whole were experiencing a fenomenally rapid economical growth phase, knwon as the “Economic Miracle”.
With Tokyo’s population booming, TRTA embarked in an extensive line-building plan, wich brought the opening of several lines in rapid succession.
In this period, TRTA also pionieered the regular, and extensive usage of several new technologies, such as the Current Chopper traction control, advanced in-cab ATC signalling, computer-aided train dispatching and several more.
At the heyday of TRTA, in the 1990s, it’s network was composed by eight lines totalling more than 150 Km and carrying several million passengers per day.
TRTA was a semi-pubblic company owned and administered directly by the Ministry of Transportation and by the Tokyo Metropolitan Government (wich also owned it’s own subway company: Toei Subway, a division of the TMGBT – Tokyo Metropolitan Government’s Bureau of Transportation).
In 2004, TRTA was restructured and rebranded as “Tokyo Metro”.
the JNR (Japanese National Railways) owned a conspicuous part of TRTA’s shares until their privatization in 1987.
TRTA’s english name is only partially translated: “Teito” actually means “Imperial Capital”, and the whole acronym, when translated into english, reads as “the Imperial Capital Rapid Transit Authority”.
Line No.3 – Ginza Line
Line No.4 – Marunouchi Line
Honancho Branch Line
Line No.2 – Hibiya Line (trough-services on the Tokyu Toyoko Line and the Tobu Iseaki Line)
Line No.5 – Tozai Line (trough services with JNR/JR East’s Chuo-Sobu Line from both terminuses)
Line No.9 – Chiyoda Line (trough services on JNR/JR East’s Joban Line and the Odakyu Odawara and Tama Lines)
Ayase Branch Line
Line No.8 – Yurakucho Line (trough-services on the Seibu Ikebukuro Line and the Tobu Tojo Line)
Line No.11 – Hanzomon Line (trough-services on the Tokyu Denentoshi Line and the Tobu Iseaki Line)
Note that the lines are ordered by opening date (from the oldest to the newest) – as with many subway systems worldwide, the line’s number does not necessarily such order.
Icons made by Curoka