Tokyo Metro Chiyoda Line
The Tokyo Metro Chiyoda Line is a subway line in Tokyo, Japan, operated by Tokyo Metro, extending 24.0 kilometers from Yoyogi-uehara Station in Shibuya to Kita-Ayase Station in Adachi and serving 20 stations along a primarily northeast-southwest alignment through the city's central districts.[1][2] It features a 2.1-kilometer branch from Ayase to Kita-Ayase, with the main line facilitating through services to the Odakyu Odawara Line westward and the JR East Jōban Line eastward, enhancing connectivity beyond Tokyo Metro's network.[3][4] Initial operations began on December 20, 1969, with the 16.5-kilometer section from Otemachi to Kitasenju, marking the first subway construction in Tokyo following World War II amid postwar urban expansion and population growth.[5] Extensions followed, reaching Yoyogi-kōen by March 1972 and Yoyogi-uehara in December 2000 via integration with Odakyu tracks, while the Kita-Ayase branch opened in 1971 with through-running implemented in 2019 to improve access to developing residential areas.[4][3] The line employs automated train operation (ATO) and supports a maximum speed of 80 km/h on the main route, contributing to Tokyo Metro's overall daily capacity of 6.84 million passengers as part of the broader 195-kilometer system.[6] Designated by green on maps, the Chiyoda Line links upscale shopping areas like Omotesando and Harajuku with government hubs such as Kasumigaseki and financial centers like Otemachi, underscoring its role in alleviating congestion on parallel routes like the Yamanote Line through efficient underground routing and interline transfers at stations including Hibiya and Akihabara.[2][7] Rolling stock, including the modern 16000 series introduced in 2010, features advanced signaling for reliable service amid Tokyo's high-density commuting demands.[8]Route and Infrastructure
Line Description and Alignment
The Tokyo Metro Chiyoda Line spans 24.0 kilometers, connecting Yoyogi-Uehara Station in Shibuya Ward with Kita-Ayase Station in Adachi Ward via 20 stations.[6][2] The route originates at the elevated Yoyogi-Uehara terminus, shared with the Odakyu Odawara Line, before transitioning to an underground alignment that constitutes the entirety of the remaining track.[4] From Yoyogi-Uehara (C01), the line proceeds northeast through Yoyogi-Koen (C02), Meiji-Jingumae (C03, serving Harajuku), Omote-Sando (C04), Nogizaka (C05), Akasaka (C06), and reaches the governmental district at Kokkai-Gijidomae (C07) and Kasumigaseki (C08).[2] It then shifts eastward to Hibiya (C09) and Nijubashimae (C10, near Marunouchi), followed by the Otemachi business area (C11), before curving north to Shin-Ochanomizu (C12), Yushima (C13), Nezu (C14), Sendagi (C15), Nishi-Nippori (C16), Machiya (C17), Kita-Senju (C18), Ayase (C19), and the branch terminus Kita-Ayase (C20).[2] This double-tracked configuration supports rapid transit through densely urbanized zones, with the alignment enabling through services to the Odakyu Odawara Line southwest and JR Joban Line northeast, though the core Tokyo Metro segment remains fully segregated underground except at the southwest end.[6][4]Technical Specifications and Engineering Features
The Tokyo Metro Chiyoda Line spans 24.0 kilometers and consists of double tracks along its entire alignment.[9] It utilizes a narrow track gauge of 1,067 mm and is electrified at 1,500 V DC through overhead catenary systems.[10] The line employs a Continuous Speed Automatic Train Control (CS-ATC) signaling system throughout, implemented in 1999 to enhance safety and operational efficiency by continuously monitoring train speeds and enforcing speed restrictions.[11] Portions of the route, particularly those interfacing with through services on the JR East Jōban Line, incorporate Automatic Train Operation (ATO) capabilities, introduced around 2018 to automate acceleration, braking, and stopping while maintaining driver oversight.[12] Predominantly underground, the Chiyoda Line's infrastructure relies on cut-and-cover construction in shallower urban sections and shield tunneling for deeper alignments to accommodate geological challenges in Tokyo's sedimentary basin.[13] These methods facilitate the line's passage beneath densely built areas, with tunnels typically featuring concrete linings for structural integrity. Engineering designs prioritize minimal surface disruption during construction, reflecting Japan's emphasis on integrating rapid transit into existing cityscapes without compromising stability. Seismic resilience forms a core engineering feature, with tunnels and associated structures reinforced using base isolation, viscous dampers, and flexible joints to absorb and dissipate energy from earthquakes exceeding magnitude 7.0.[14] Post-1995 Hanshin earthquake assessments prompted Tokyo Metro to retrofit vulnerable segments, including enhanced pillar strengthening and track fastening systems to prevent derailments or collapses during strong ground motion.[15] These measures, verified through shake-table testing and historical performance data, ensure operational continuity and passenger safety in a seismically active region.Operations and Services
Daily Service Patterns
The Tokyo Metro Chiyoda Line operates daily from approximately 5:00 a.m. to midnight, with first trains departing terminal stations such as Yoyogi-Uehara and Ayase around 5:00–5:10 a.m. and last trains arriving at terminals by about 12:00 a.m.[16][17] Weekday services ramp up progressively from early morning, peaking during commuter rush hours of 7:00–9:00 a.m. toward central Tokyo and 5:00–7:00 p.m. away from the center, before tapering off in the late evening. Weekend and holiday schedules feature reduced frequencies overall, starting later (around 5:30 a.m.) and ending similarly, with no rush-hour surges. Within the core Yoyogi-Uehara to Ayase segment, all Tokyo Metro-operated trains function as local services, stopping at every station regardless of time or day. Frequencies during weekday peak periods achieve headways as short as 2 minutes on the main line to manage high demand, reflecting Tokyo Metro's capacity for intense commuter volumes. Off-peak weekday intervals extend to 4–6 minutes, while weekends maintain roughly 5–10 minute headways throughout operating hours. These patterns support through-running with the Odakyu Line southward from Yoyogi-Uehara and the JR Jōban Line northward from Ayase, where stopping patterns may vary on the extended segments but remain all-stops within Tokyo Metro limits.[18][19] The Kita-Ayase branch, a 1.5 km shuttle extension from Ayase, operates independently with lower frequencies: approximately 8–9 trains per hour (6–7 minute headways) toward Ayase during weekday morning peaks, reducing off-peak and on weekends. This branch connects directly to the main line at Ayase without through services, serving local residential demand in Adachi Ward.[19] Service reliability is high, with normal operations reported consistently, though minor adjustments like frequency tweaks have occurred post-2022 to optimize energy use during peaks.[2]Through Services and Interconnections
The Tokyo Metro Chiyoda Line operates through services with the Odakyu Electric Railway at Yoyogi-Uehara station, enabling select trains to continue directly onto the Odakyu Odawara Line toward Hon-Atsugi and onto the Tama Line toward Karakida. These operations integrate Tokyo's central subway network with Kanagawa Prefecture's suburban rail system, primarily serving peak-hour commuters by reducing transfer needs. Through-running to the Tama Line resumed in March 2025 after a suspension since 2022, reflecting adjustments to demand patterns on Odakyu routes.[7][20][21] At Ayase station, the Chiyoda Line interconnects with JR East's Jōban Line via through services on local trains, extending northeast to stations including Matsudo, Abiko, and Toride in Chiba Prefecture. This linkage, operational since the line's extension to Ayase in 1969, supports high-volume commuter flows from Chiba's satellite towns into central Tokyo, with trains maintaining compatibility in voltage, signaling, and platform lengths for seamless integration. Daily timetables confirm regular through patterns, such as local services to Abiko during weekdays.[22][23][24] These through services utilize shared rolling stock standards, with Tokyo Metro's 16000-series trains and compatible Odakyu and JR vehicles operating interchangeably under mutual agreements, though platform screen doors and automatic train control systems ensure safety across operators. Interconnections at intermediate stations, such as Otemachi for transfers to the Marunouchi and Toei Mita lines or Kita-Senju for the Hibiya and Tsukuba Express lines, provide additional cross-network access but rely on passenger changes rather than direct through-running. The Kita-Ayase branch, however, functions solely as a shuttle to Ayase without extensions or through services.[2][25]Ridership and Performance Metrics
The Tokyo Metro Chiyoda Line contributes substantially to the operator's overall passenger volume, part of the network's average daily ridership of 6.84 million passengers in fiscal year 2024 (April 2023 to March 2024).[6] Individual station data underscores the line's intensity, with Kita-Senju Station recording 241,001 average daily passengers and Nishi-Nippori Station at 154,330 in the same period, reflecting heavy commuter flows through northeastern and central Tokyo interchanges.[26] Other notable stations include Kasumigaseki (132,884 daily passengers) and Akasaka (77,718), highlighting the line's role in serving government districts and business areas.[27][26]| Station | Line | Daily Average Passengers (FY2024) | Year-on-Year Change (%) |
|---|---|---|---|
| Kita-Senju | Chiyoda Line | 241,001 | +3.8 |
| Nishi-Nippori | Chiyoda Line | 154,330 | +2.2 |
| Kasumigaseki | Chiyoda Line (shared) | 132,884 | N/A |
| Akasaka | Chiyoda Line | 77,718 | +4.8 |
Stations
Main Line Stations
The main line of the Tokyo Metro Chiyoda Line consists of 19 stations spanning approximately 21.9 km from Yoyogi-Uehara in Shibuya ward to Ayase in Adachi ward, traversing wards including Shibuya, Minato, Chiyoda, Bunkyō, Taito (briefly without station), Arakawa, and Adachi.[2][31] Yoyogi-Uehara station at the western terminus interchanges with the Odakyu Odawara Line, facilitating through services, while Ayase at the eastern end connects to the JR Jōban Line.[32] The route primarily runs underground, serving business districts, government areas, and residential neighborhoods with key interchanges to other Tokyo Metro lines and JR lines at stations such as Omote-Sando, Otemachi, and Kita-Senju.[2]| Station No. | Station Name | Code |
|---|---|---|
| 1 | Yoyogi-Uehara | C01 |
| 2 | Yoyogi-Koen | C02 |
| 3 | Meiji-Jingumae (<Harajuku>) | C03 |
| 4 | Omote-Sando | C04 |
| 5 | Nogizaka | C05 |
| 6 | Akasaka | C06 |
| 7 | Kokkai-Gijidomae | C07 |
| 8 | Kasumigaseki | C08 |
| 9 | Hibiya | C09 |
| 10 | Nijubashimae (<Marunouchi>) | C10 |
| 11 | Otemachi | C11 |
| 12 | Shin-Ochanomizu | C12 |
| 13 | Yushima | C13 |
| 14 | Nezu | C14 |
| 15 | Sendagi | C15 |
| 16 | Nishi-Nippori | C16 |
| 17 | Machiya | C17 |
| 18 | Kita-Senju | C18 |
| 19 | Ayase | C19 |
Branch Line and Kita-Ayase Extension
The Chiyoda Line's branch line extends 2.1 km north from Ayase station to Kita-Ayase station, primarily providing access to the Ayase depot.[3] Opened on December 20, 1979, alongside the depot, the branch initially operated as a shuttle service using 3-car trains to serve the developing residential area in Adachi ward.[3][34] Kita-Ayase station, the branch's sole passenger stop, featured a platform designed for 3-car formations upon opening, limiting service to short shuttle runs from Ayase without direct connections to the main line.[3] This configuration persisted for nearly four decades, with operations separated from the primary Yoyogi-Uehara to Ayase route despite shared infrastructure at Ayase.[3] On March 16, 2019, Tokyo Metro implemented through services on the branch, enabling direct runs from Kita-Ayase to Yoyogi-Uehara using 10-car 16000 series trains, interspersed with existing Jōban Line extensions from Toride.[3] To support longer consists, the Kita-Ayase platform was extended by 135 meters, and a new entrance with elevators was added to enhance accessibility.[3] This upgrade replaced the prior shuttle operations and four retained 05 series 3-car sets, aligning branch capacity with main line standards while retaining operational separation in peak patterns.[3]Rolling Stock
Current Active Fleet
The primary rolling stock for the main Tokyo Metro Chiyoda Line consists of the 16000 series electric multiple units, which entered service on November 10, 2010, to replace older 6000 and 06 series trains.[35] These trains operate in 10-car formations, with a total of 37 sets in service as of recent fleet overviews.[35] Designed for high-capacity urban commuting, the 16000 series features variable voltage variable frequency (VVVF) inverter control for efficient traction and regenerative braking, along with static inverters for auxiliary power supply.[10] For the Kita-Ayase Branch Line, operations utilize four 3-car formations of the 05 series, transferred from the Tozai Line and introduced in April 2014 to replace the 5000 series on this short shuttle service.[36] These sets, specifically 05-101, 05-103, 05-106, and 05-113, maintain compatibility with the branch's infrastructure, including its 1,067 mm gauge and 1,500 V DC overhead electrification.[36] The 05 series employs gate turn-off thyristor (GTO) control systems, reflecting technology from their original 1988 deployment era, though refurbished for continued reliability.[36]| Series | Formation | Number of Sets | Introduction Date | Primary Use |
|---|---|---|---|---|
| 16000 | 10 cars | 37 | November 2010 | Main line |
| 05 | 3 cars | 4 | April 2014 | Kita-Ayase Branch |