List of longest subway tunnel sections
{{Short description|none}}
{{Use dmy dates|date=September 2018}}
{{more citations needed|date=June 2016}}
This page presents a list of the longest continuous underground rapid transit tunnel sections of the world, excluding branches from the longest tunnel (branch lines that used to transport passengers should be included).
Note: This article only lists tunnels that are 15 km (6.2 miles) or longer.
World's longest subway tunnel sections in use
{{srn}}
{{mw-datatable}}
| class="wikitable sortable mw-datatable static-row-numbers" |
| class=static-row-header
! width=220pt|Name ! width=220pt|System ! Country ! Stations ! Length in km (mi) ! Year of |
| Lines 3-11
| rowspan="6" | {{flag|China}} | Line 3 and Line 11 are connected at Weiting Station with through trains passing by. | {{convert|86.54|km|mi|abbr=on}} | 2019–2023 |
| Line 6
| {{convert|68.2|km|mi|abbr=on}} {{cite web|url=https://kscgc.sctv.com/sctv/redian/2020/09/09/989474_shared.html|date=2020-09-09|title=独家探访{{!}}关于西部最长地铁6号线，你想知道的一切都在这里|quote=成都地铁6号线全长68.76千米，共设有56座车站}} | 2020 |
| Line 3
| Haibang – Airport North | {{convert|68.2|km|mi|abbr=on}} | 2005–2024 |
| Line 19
| {{convert|67|km|mi|abbr=on}} | 2020–2023 |
| Line 1
| Dongguozhuang to Wangjiagang | {{convert|59.82|km|mi|abbr=on}} | 2020–2021 |
| Line 18
| {{stl|GZM|Xiancun}} to {{stl|GZM|Wanqingsha}} | 2021 |
| Bolshaya Koltsevaya line
| {{flag|Russia}} | Circle route | {{convert|57.54|km|mi|abbr=on}}{{cite web | url=https://1520today.ru/blog/ne-70-km-a-57-5-kak-moskovskie-vlasti-udlinili-bolshuju-kolcevuju-liniju-metro | title=Не 70 км, а 57,5! Как московские власти "удлинили" Большую кольцевую линию метро | date=22 March 2023 }}{{cite web | url=https://postimg.cc/bsQtrNg0 | title=IMG 20230327 063939 969 — Postimages }} |
| Line 10
| rowspan="3" | {{flag|China}} | Circle route | 57.1 (35.5) | 2008–2013 |
| Line 5
| {{stl|HZM|East Nanhu |
| 56.0 (34.93)
| 2019-2025
|-
| Line 7
| {{stl|GZM|Meidi Dadao|}} – {{stl|GZM|Yanshan}}
| 54.24 (33.7)
| 2016–2023
|-
| Line 6
| {{flag|China}}
| {{stl|BJS|Jin'anqiao}}–{{stl|BJS|Lucheng}}
| 53.4 (33.2)
|2012-2018
|-
| Seoul Subway Line 5
(longest branch)
| {{sort|Korea, South|{{flag|South Korea}}}}
| {{convert|51.7|km|mi|abbr=on}}
| 1995–2021
|-
| M11
| {{flag|Turkey}}
| Gayrettepe – Arnavutköy Hastane
| 51.5 (32)
| 2023–2024
|-
| Line 2
| rowspan="2" | {{flag|China}}
| Julong Boulevard - Fozuling
| 50.347 (27.556)
| 2012–2019
|-
| Line 16
| {{stl|BJS|Bei'anhe}} – Wanpingcheng
| 48.9 (30.4)
| 2016–2023
|-
| rowspan="3" | {{flag|Russia}}
| Potapovo – Bulvar Rokossovskogo
| 47 (29)
| 1935–2024
|-
| Pyatnitskoye Shosse – Shchyolkovskaya
| 45.1 (28.0)
| 1938–2012
|-
| Lyublinsko-Dmitrovskaya line
| Zyablikovo – Fiztekh
| 44.3 (27.5)
| 1995–2023
|-
| Line 11
| {{flag|China}}
| {{convert|43.2|km|mi|abbr=on}}
| 2024
|-
| {{flag|Russia}}
| 42.8 (26.6)
| 1938–2018
|-
| Line 8
| rowspan="3" | {{flag|China}}
| {{stl|BJS|Yuzhi Lu}} – {{stl|BJS|Wufutang}}
| 42.6 (26.4)
| 2012–2021
|-
| Line 15
| Gucun Park – Zizhu Hi-tech Park
| 42.3 (26.3)
| 2021
|-
| Line 5
| 42.3 (26.3)
| 2019
|-
| Tagansko-Krasnopresnenskaya line
| {{flag|Russia}}
| Planernaya – Kotelniki
| 42.2 (26.2)
| 1966–2015
|-
| Line 14
| rowspan="2" | {{flag|China}}
| {{stl|BJS|Dawayao}} – {{stl|BJS|Shan'gezhuang}}
| 42 (26)
| 2015–2021
|-
| Line 6
| {{stl|TJM|Nanhezhuang}} – {{stl|TJM|Lushuidao}}
| 42 (26)
| 2016–2021
|-
| Mass Rapid Transit (Singapore)
| {{flag|Singapore}}
| Bukit Panjang – Expo
| 2013–2017
|-
| Line 3
| rowspan="2" | {{flag|China}}
| 41.5 (25.8)
| 2015
|-
| Line 4
| Longdaobang — Tongli
| 41.5 (25.8)
| 2017
|-
| Serpukhovsko-Timiryazevskaya line
| {{flag|Russia}}
| Altufyevo – Bulvar Dmitriya Donskogo
| 41.2 (25.6)
| 1983–2002
|-
| L-12 (Metro Sur)
| {{flag|Spain}}
| Circle route
| 40.96 (25.5)
| 2003
|-
| Toei Oedo Line {{Citation needed|date=January 2010}}
| {{flag|Japan}}
| Hikarigaoka – Shiodome – Tocho-mae
| 40.7 (25.3)
| 2000
|-
| {{sort|Korea, South|{{flag|South Korea}}}}
| Gimpo Airport – VHS Medical Center
| 40.6 (25.2)
| 2018
|-
| Line 12
| rowspan="4" | {{flag|China}}
| 40.4 (25.1)
| 2015
|-
| Line 7
| {{stl|BJS|Beijing West railway station}} - {{stl|BJS|Universal Resort}}
| 40.3 (25.0)
| 2021
|-
| Line 4
| Wansheng – Chengdu University
| 39.3 (24.4)
| 2015–2017
|-
| Line 7
| Circle route
| 38.6 (24.0)
| 2017
|-
|-
| {{flag|Russia}}
| Medvedkovo – Novoyasenevskaya
| 37.8 (23.5)
| 1958–1990
|-
| Line 1
| rowspan="2" | {{flag|China}}
| Weijianian – Science City
| 37.47 (23.3)
| 2010–2018
|-
| Line 2
| 35.78 (22.23)
| 2011
|-
| Busan Transportation Corporation
| rowspan="3" | {{sort|Korea, South|{{flag|South Korea}}}}
| 35.5 (22.06)
| 1999
|-
| 35.1 (21.8)
| 2001
|-
| Seoul Subway Line 7
(longest branch)
| Cheongdam – Bupyeong-gu Office
| 35.1 (21.7)
| 2012
|-
| Line 5
| rowspan="3" | {{flag|China}}
| {{stl|TJM|Beichenkejiyuanbei}} – {{stl|TJM|Liqizhuangnan}}
| 34.8 (21.6)
| 2018–2021
|-
| Line 7
| 34.4 (21.38)
| 2010
|-
| Line 8
| 33.9 (21.1)
| 2010–2020
|-
| M4
| {{flag|Turkey}}
| Kadıköy – Sabiha Gökçen Havalimanı
| 33.5 (20.8)
| 2012–2022
|-
| Mass Rapid Transit (Singapore)
| {{flag|Singapore}}
| 2009–2012
|-
| L-7
| {{flag|Spain}}
| Hospital del Henares – Pitis
| 32.9 (20.5)
| 2007
|-
| U7
| {{flag|Germany}}
| 31.8 (19.7)"World's longest railway tunnel" 1984–1988
| 1924–1984
|-
| Line 1
| {{flag|China}}
| {{stl|BJS|Pingguo Yuan}} – {{stl|BJS|Dawang Lu}}
| 31.0 (19.3)
| 1971–2000
|-
| {{flag|Russia}}
| Aeroport Vnukovo – Delovoy Tsentr
| 30.9 (19.2)
| 2014–2023
|-
| IND Eighth Avenue Line and IND Fulton Street LineNote that both lines are served continuously by the {{NYCS|A}} train within a single tunnel.
| {{flag|United States}}
| Inwood – 207th Street – Grant Avenue
| 30.8 (19.14)
| 1956
|-
| {{flag|Canada}}
| 30.8 (19.14)
| 2007
|-
| Mass Rapid Transit (Singapore)
| {{flag|Singapore}}
| Woodlands North – Gardens by the Bay
| {{convert|30.4|km|mi|abbr=on}}
| 2020–2022
|-
| Line 2
| {{flag|China}}
| 30.2 (18.77)
| 2010
|-
| Moskovsko-Petrogradskaya Line
| {{flag|Russia}}
| 30.1 (18.7)
| 1961–2006
|-
| Line 8
| {{flag|China}}
| 29.7 (18.45)
| 2009
|-
| {{flag|Russia}}
| Devyatkino – Prospekt Veteranov
| 29.57 (18.4)
| 1955–1978
|-
| Line 8
| rowspan="2" | {{flag|China}}
| (Phase 2 is 7.94 km)
| 29.1 (18.1)
| 2020
|-
| Line 2
| Tianhe Road – Chengdu Institute of Public Administration
| 29.0 (18.0)
| 2012–2013
|-
| Bannan Line (Taipei Metro Blue Line)
| {{flag|Taiwan}}
| Dingpu – Taipei Nangang Exhibition Center
| 28.2 (17.6)
| 1999–2015
|-
| Line 4
| {{flag|China}}
| {{stl|BJS|Anheqiao Bei (N)}} – {{stl|BJS|Gongyi Xiqiao}}
| 28.2 (17.5)
| 2009–2010
|-
| {{sort|Korea, South|{{flag|South Korea}}}}
| Bakchon – International Business District
| 27.9 (17.42)
| 1999–2009
|-
| Line 14
| {{flag|France}}
| Saint-Denis–Pleyel – Aéroport d'Orly
| 27.8 (17.3)
| 1998–2024
|-
| {{flag|United Kingdom}}
| Morden – East Finchley
| 27.8 (17.2)
| 1890–1940
|-
| Nevsko-Vasileostrovskaya Line
| {{flag|Russia}}
| 27.7 (17.2)
| 1967–2018
|-
| {{flag|Japan}}
| 27.1 (16.7)
| 1967–1983
|-
| M5
| {{flag|Turkey}}
| 26.5 (12.5)
| 2017–2024
|-
| Meijo Line {{Citation needed|date=March 2010}}
| {{flag|Japan}}
| Kanayama–Nagoya Dome-mae Yada-Kanayama
| 26.4 (16.4)
| 1965–2004
|-
| B Line
| {{flag|United States}}
| {{LAMs|North Hollywood}} - {{LAMs|Union Station}}
| 26.4 (16.4)
| 1993–2000
|-
| {{flag|Russia}}
| Komendantsky Prospekt – Shushary
| 26.2 (16.3)
| 1997–2019
|-
| Line 1
| {{flag|China}}
| Mudu – Zhongnan Jie
| 25.7 (16.0)
| 2012
|-
| Line 3
| {{flag|Greece}}
| {{metro|Dimotiko Theatro}} – Doukissis Plakentias
| 25.3 (15.72)
| 2023
|-
| {{flag|Finland}}
| Kalasatama – Kivenlahti
| 25.2 (15.7)
| 1982–2022
|-
| {{flag|Taiwan}}
| 25.1 (15.6)
(longest branch)
| 1998–2013
|-
| Line 3
| {{flag|Chile}}
| Plaza de Quilicura - Fernando Castillo Velasco
| 25 (13.5)
| 2019–2023
|-
| {{flag|Japan}}
| Chikatetsu Narimasu – Tatsumi
| 24.6 (15.3)
| 1974–1988
|-
| U2
| {{flag|Germany}}
| Feldmoching – Messestadt Ost
| 24.4 (15.2)
| 1980–2001
|-
| {{flag|India}}
| 24 (14.9){{cite news|url=http://www.thehindu.com/news/cities/Delhi/article611319.ece|title=Metro to bridge Delhi-Gurgaon divide today|date=2010-09-03|access-date=2010-10-19|location=Chennai, India|work=The Hindu}}{{cite news|url=http://news.webindia123.com/news/articles/India/20100829/1576007.html|title=Gurgaon Metro set for operationalisation next week|author=Rajesh Ahuja|date=2010-08-29|access-date=2010-10-19}}
| 2009–2010
|-
| L-1
| rowspan="2" | {{flag|Spain}}
| Valdecarros – Pinar de Chamartín
| 23.88 (14.84)
| 1919–2007
|-
| L-6
| Circle route
| 23.47 (14.58)
| 1979–2007
|-
| Line 9
| {{flag|China}}
| Jiuting – Middle Yanggao Road
| 23.3 (14.48)
| 2007–2010
|-
| {{flag|Canada}}
| Angrignon – Honoré-Beaugrand
| 23.26 (14.45)
| 1966–1978
|-
| {{flag|Poland}}
| 23.1 (14.35)
| 1995–2008
|-
| Line 2
| {{flag|China}}
| Circle route
| 23.1 (14.35)
| 1984–1987
|-
| M3
| {{flag|Turkey}}
| Bakırköy Sahil – Şehir Hastanesi Viaduct
| 22.6 (16.6)
| 2013–2024
|-
| Line 9
| rowspan="2" | {{flag|China}}
| Phase 1 of the second loop line in Chengdu, all underground
| {{convert|22.18|km|mi|abbr=on}}
| 2020
|-
| Line 19
| {{stl|BJS|Mudan Yuan}} – {{stl|BJS|Xin Gong}}
| 22.4 (13.9)
| 2021
|-
| Songshan-Xindian Line (Taipei Metro Green Line)
| {{flag|Taiwan}}
| 21.3 (13.2)
| 1998–2014
|-
| Line 4
| {{flag|China}}
| 21.1 (13.11)
| 2005–2007
|-
| {{flag|Japan}}
| Meguro – Shimura-Sakaue
| 21.1 (13.11)
| 1968–2000
|-
| {{flag|United Kingdom}}
| Walthamstow Central – Brixton
| 21.0 (13.05)
| 1968–1971
|-
| {{flag|Ukraine}}
| 20.95 (13.02)
| 1976–2013
|-
| Line 6
| {{flag|China}}
| Boxing Road – Oriental Sports Center
| 20.34 (12.64)
| 2007–2011
|-
| Line 1
| {{flag|Spain}}
| Fondo – Hospital de Bellvitge
| 20.2 (12.56)
| 1926–1989
|-
| Tozai Line {{Citation needed|date=September 2009}}
| Sapporo Municipal Subway {{Citation needed|date=September 2009}}
| {{flag|Japan}}
| Miyanosawa – Shin-Sapporo {{Citation needed|date=September 2009}}
| 20.1 (12.4)
| 1976–1999
|-
| M1
| {{flag|Turkey}}
| Koru – Atatürk Kültür Merkezi
| 20.1 (12.4)
| 1997–2014
|-
| L-5
| rowspan="2" | {{flag|Spain}}
| 20.005 (12.5)
| 1968–2006
|-
| Line 9
| Zona Universitaria – Aeroport T1
| 20.0 (12.5)
| 2004–2016
|-
| Mass Rapid Transit (Singapore)
| {{flag|Singapore}}
| 2003–2011
|-
| {{flag|Romania}}
| 20.0 (12.43)
| 1983–2008
|-
| Line 7
(longest branch)
| {{flag|France}}
| La Courneuve–8 mai 1945 – Villejuif–Louis Aragon
| 19.8 (12.3)
| 1910-1987
|-
| Line 2
| {{flag|China}}
| {{stl|TJM|Caozhuang}} – {{stl|TJM|Guoshanlu}}
| 19.7 (12.2)
| 2012–2014
|-
| {{flag|Russia}}
| Nizhegorodskaya – Nekrasovka
| 19.6 (12.2)
| 2019–2020
|-
| Line 9
| {{flag|France}}
| Pont de Sèvres – Mairie de Montreuil
| 19.6 (12.2)
| 1922–1937
|-
| M2
| {{flag|Turkey}}
| Şişhane – Hacıosman
Line is 23,49 km long, but the longest continuous underground section is 19.54 km long.
| 19.54 (12.14)
| 2000–2014
|-
| Red, Yellow, Blue, and Green Lines
| Bay Area Rapid Transit, San Francisco
| {{flag|United States}}
| {{bart|Balboa Park}} – {{bart|West Oakland}}
| 19.5 (12.12)
| 1973
|-
| {{flag|Australia}}
| {{cvt|19.5|km|mi|1}}
| 2009–2019
|-
| {{flag|Russia}}
| Circle route
| 19.4 (12.2)
| 1950–1954
|-
| U3
| {{flag|Germany}}
| 19.4 (12.05)
| 1972–2009
|-
| Line 4
| rowspan="2" | {{flag|China}}
| {{stl|TJM|Dongnanjiao}} – {{stl|TJM|Xinxingcun}}
| 19.4 (12)
| 2021
|-
| Line 3
| {{stl|TJM|Huayuan}} – {{stl|TJM|Tianshili}}
| 19.2 (11.9)
| 2012–2013
|-
| {{flag|Belarus}}
| 19.1 (11.9)
| 1984–2014
|-
| {{flag|Japan}}
| 19.1 (11.87)
| 1933–1987
|-
| Line 5
| {{flag|Spain}}
| Vall d'Hebron – Cornella centre
| 19.0 (11.8)
| 1955–2010
|-
| {{flag|Poland}}
| {{convert|18.9|km|mi|abbr=on}}
| 2015–2022
|-
| {{flag|Mexico}}
| La Raza – Universidad
| 18.7 (11.62)
| 1970–1983
|-
| Red Line
| {{flag|Azerbaijan}}
| {{stl|Baku Metro|Icheri Sheher}} – {{stl|Baku Metro|Hazi Aslanov}}
| 18.6 (11.6)
| 1967–2002
|-
| Line 7
(shorter branch)
| {{flag|France}}
| La Courneuve–8 mai 1945 – Mairie d'Ivry
| 18.5 (11.5)
| 1910-1987
|-
| Line 3
| {{flag|Spain}}
| Zona Universitària – Trinitat Nova
| 18.4 (11.44)
| 1925–2008
|-
| Line 1
| {{flag|China}}
| Shanghai South Railway – Shanghai Circus World
| 18.1 (11.25)
| 1993–2004
|-
| {{flag|Belarus}}
| Kamennaya Gorka – Mogilevskaya
| 18.1 (11.25)
| 1990–2005
|-
| U8
| {{flag|Germany}}
| 18.1 (11.25)
| 1927–1996
|-
| Line B
| {{flag|Czechia}}
| Rajská zahrada – Hůrka
| 18.0 (11.2)
| 1998
|-
| Line 2{{cite web|url=http://www.amel.gr/index.php?id=22&L=1|title=Urban Rail Transport SA :METRO Line 1|publisher=|access-date=30 September 2014}}
| {{flag|Greece}}
| Anthoupoli – Elliniko
| 17.9 (11.12)
| 2013
|-
| Line 5
| {{flag|China}}
| {{stl|BJS|Huixin Xijie Beikou}} – {{stl|BJS|Songjiazhuang}}
| 17.8 (11.1)
| 2007
|-
| Washington, DC Metro Red Line
| {{flag|United States}}
| Union Station – Medical Center
| 17.8 (11.05)
| 1984
|-
| Line 15
| {{flag|China}}
| {{stl|BJS|Qinghua Donglu Xikou}} – {{stl|BJS|Maquanying}}
| 17.6 (10.9)
| 2014
|-
| {{flag|Japan}}
| Uzumasa Tenjingawa-Yamashina-Rokujizo
| 17.5 (10.92)
| 2008{{page needed|date=May 2020}}
|-
| Line 27
| {{flag|China}}
| {{convert|17.34|km|mi|abbr=on}}
| 2024
|-
| Line 4
| {{flag|Spain}}
| Trinitat Nova – La Pau
| 17.3 (10.76)
| 1908{{clarify|date=October 2021|reason=When was the line converted from overground to underground? 1908?}}–1999
|-
| Kholodnohirsko–Zavodska line
| {{flag|Ukraine}}
| Kholodna Hora – Industrialna
| 17.3 (10.7)
| 1975–1978
|-
| Line 12
| {{flag|France}}
| Mairie d'Aubervilliers – Mairie d'Issy
| 17.2 (10.7)
| 1910–2022
|-
| {{flag|Italy}}
| Comasina – San Donato
| 17.105 (10.62)
| 1990–2011
|-
| {{flag|Romania}}
| 17.1 (10.62)
| 1986–1987
|-
| {{flag|Japan}}
| 17.0 (10.56)
| 1969
|-
| M1
| {{flag|Turkey}}
| Kaymakamlık – Basmane
Line is 27 km long, but only 19.8 km of it is underground in two noncontinuous sections. The shorter underground section is 2.9 km long.
| 16.9 (10.5)
| 2000–2024
|-
| Line 13
(longest branch)
| {{flag|France}}
| Malakoff–Plateau de Vanves – Saint-Denis-Université
| 16.8 (10.5)
| 1911–1998
|-
| {{flag|Japan}}
| 16.8 (10.4)
| 1978–2003
|-
| {{flag|Mexico}}
| 16.7 (10.38)
| 1984
|-
| {{flag|India}}
| {{stl|Chennai Metro|Saidapet}} - {{stl|Chennai Metro|Tondiarpet}}
| 16.6 (10.32)
| 2018–2021
|-
| Line 9
| rowspan="2" | {{flag|China}}
| {{stl|BJS|National Library}} – {{stl|BJS|Guogongzhuang}}
| 16.5 (10.3)
| 2012
|-
| Line 17
| {{stl|BJS|Shilihe}} – {{stl|BJS|Jiahuihu}}
| 16.5 (10.3)
| 2021
|-
| L-3
| {{flag|Spain}}
| 16.42 (10.2)
| 2007
|-
| Line 1
| {{flag|China}}
| Chaotianmen – Shapingba
| 16.4 (10.2)
| 2011
|-
| Line A
| {{flag|Czechia}}
| Nemocnice Motol – Depo Hostivař
Line is 17.1 km long, but only 16.4 km of it is underground.
| 16.4 (10.2)
| 2015
|-
| {{flag|Russia}}
| 16.3 (10.1)
| 1979–2012
|-
| Line 8
| {{flag|France}}
| 16.2 (10.1)
| 1913–1942
|-
| {{flag|Australia}}
| {{Cvt|16|km|mi|1|abbr=}}
|-
| L-4
| {{flag|Spain}}
| Argüelles – Pinar de Chamartín
| 16.0 (9.9)
| 2007
|-
| Sviatoshynsko–Brovarska line
| {{flag|Ukraine}}
| 16.0 (9.9)
| 1960–2003
|-
| Seoul Subway Line 7
(shorter section)
| {{sort|Korea, South|{{flag|South Korea}}}}
| Suraksan – Konkuk University
| 16.0 (9.9)
| 1996
|-
| U6
| {{flag|Germany}}
| Alt-Mariendorf – Kurt-Schumacher-Platz
| 15.9 (9.86)
| 1923–1966
|-
| M9
| {{flag|Turkey}}
| 15.8 (9.8)
| 2013–2024
|-
| Line B
| {{flag|France}}
| Borderouge to Ramonville
| 15.7 (9.8)
| 2007
|-
| {{flag|Denmark}}
| Circle route
| {{convert|15.5|km|mi|abbr=on}}
| 2019
|-
| Line 3{{cite web|title=3-as metróvonal jellemzői |url=http://metros.hu/vonal/jellemzok_m3.html|website=Metros.hu|access-date=27 March 2016|language=Hungarian}}
| {{flagicon|Hungary}} Hungary
| Határ út–Újpest-központ
Line is 17.39 km long, but only 15.5 km of it is underground.
| {{convert|15.5|km|mi|1|abbr=on}}
| 1990
|-
| Line 1
| {{flag|China}}
| {{stl|TJM|Qinjiandao}} – {{stl|TJM|Tucheng}}
| 15.37 (9.55)
| 2006
|-
| Line 6
| {{flag|Chile}}
| Cerrillos – Los Leones
| 15.3 (9.5)
| 2017
|-
| {{flag|Ukraine}}
| 15.2 (9.4)
| 1989–2004
|-
| {{flag|India}}
| Mahanayak Uttam Kumar -Dum Dum
| 15.17 (9.38)
| 1984–1995
|-
| Line 10
| {{flag|China}}
| {{stl|CDM|Taipingyuan}} – {{stl|CDM|Shuangliu West}}
| 15.0 (9.32)
| 2019
|-
| MTR
| {{nowrap|{{flagicon|HKG|1997}} Hong Kong}}
| Kennedy TownIncluding 0.4 miles/0.65 km of overrun tunnel to the west of Kennedy Town station. - {{cite web|url=https://www.gammonconstruction.com/en/project-details.php?project_id=109|title=MTR West Island Line - Sai Ying Pun; Hong Kong University and Kennedy Town Stations - Project details|author=Gammon}} - {{cite web|url=http://www.ciht.org.hk/events/9-10-10%20Site%20Visit%20to%20705_Summary.pdf|title=West Island Line, Contact 705, KET Station & Overrun Tunnel|author=CIHT Hong Kong Branch }} – Heng Fa Chuen
| 15.0 (9.32)
| {{nowrap|1985 (as {{flag|HKG|1959|name=Hong Kong}})}}{{nowrap|–2014}}
|}
World's longest subway tunnel sections under construction
| class="wikitable sortable"
! Name ! System ! Country ! Stations ! Length ! Expected completion |
| Line 15
| {{flag|France}} | Noisy–Champs - Champigny Centre | {{convert|75|km|mi|abbr=on}} | Southern section: 2025 |
| M11
| {{flag|Turkey}} | (Phase 2, Kargo Terminali - Halkalı section is 31.5 km in length and is currently under construction, all underground) | {{convert|69|km|mi|abbr=on}} | Phase 2：2024 |
| Cross Island line
| Mass Rapid Transit (Singapore) | {{flag|Singapore}} | Linear route with branch section, all underground | {{convert|65.5|km|mi|abbr=on}} | 2030–2032 |
| Line 13
| {{flag|China}} | Whole lines is underground | {{convert|59.2|km|mi|abbr=on}} | Phase 1：2017 |
| L9 / L10
| {{flag|Spain}} | | {{convert|47.8|km|mi|abbr=on}} | 2009 and 2016 partially; |
| Line 13
| {{flag|China}} | Whole line is underground | {{convert|45.72|km|mi|abbr=on}} | Phase 1：2024 |
| Thomson–East Coast line
| Mass Rapid Transit (Singapore) | {{flag|Singapore}} | Woodlands North to Sungei Bedok | {{convert|43.4|km|mi|abbr=on}} | Phase 4：2024 |
| Line 22
| {{flag|China}} | Jinji Road - Dongtan | 40.9 km | 2026 |
| Troitskaya line
| {{flag|Russia}} | Whole line is underground | {{convert|40.2|km|mi|abbr=on}} | Phase 1：2024 ({{convert|25|km|mi|abbr=on}}) |
| Athens Metro Line 4
| {{flag|Greece}} | |
| Line 12
| {{flag|China}} | Xunfenggang – Higher Education Mega Center South | 37.6 km (23.36 mi) | 2025 |
| Metro Manila Subway
| Manila Metro Rail Transit System | {{flag|Philippines}} | Mindanao Avenue – Ninoy Aquino International Airport (All underground) | {{convert|36|km|mi|abbr=on}} | 2029 |
| Line 22
| {{flag|China}} | 34.2km | Phase 1: 2029 |
| Line 3
| {{flag|India}} | {{convert|35.52|km|mi|abbr=on}} | 2025 for Phase 1 |
| Line 6
| rowspan="3" | {{flag|China}} | Whole line is underground | 32.4 km | |
| Line 15
| Whole line is underground | 32.2 km (20.0 mi) | 2028 |
| Line 13
| Qiligou – Longhua Temple underground section | {{convert|29.07|km|mi|abbr=on}} | 2025 |
| Line 16
| {{flag|France}} | Saint-Denis–Pleyel - Noisy–Champs | {{convert|27.5|km|mi|abbr=on}} | Phase 1: 2026 |
| Line 3
| {{flag|India}} | Madhavaram Milk Colony – Tharamani | {{convert|27.086|km|mi|abbr=on}} | 2026–2027 |
| D Line Extension
| {{flag|United States}} | {{LAMs|Westwood/VA Hospital}} – {{LAMs|Union Station}} | 24.3 km (15.1 mi) | 2025–2026 |
| Line 30
| {{flag|China}} | (Phase 1 is 26.28 km) | {{convert|26.28|km|mi|abbr=on}} | 2025 |
| Suburban Rail Loop
| rowspan="3" | {{flag|Australia}} | SRL East and North is underground (Cheltenham to Airport) | {{convert|26|km|mi|abbr=on}} | 2035{{cite web | url=https://www.premier.vic.gov.au/works-start-today-victorias-suburban-rail-loop | title=Works Start Today on Victoria's Suburban Rail Loop | Premier of Victoria }} (Eastern stretch) |
| Metro West
| | {{convert|24|km|mi|abbr=on}} |
| Metro Western Sydney Airport
| | {{convert|23|km|mi|abbr=on}} | 2026 |
| Line C
| {{flag|France}} | Underground from Colomiers Gare to Montaudran Gare, full line will be 27 km long.{{cite web|url=https://www.projetsmetro.tisseo.fr/sites/default/files/media/downloads/tisseo_ligne_c_carnet_chantier_no15_tunneliers.pdf|date=2024-09-28|title=Tunnel du métro : du creusement à la construction|quote=Les cinq tunneliers de la ligne C creuseront 22 km en souterrain}} | {{convert|22|km|mi|abbr=on}} | 2028 |
| Blue Line
| {{flag|Sweden}} | The extension to Nacka will be around 8 km, all underground, total 22 km including older sections. | {{convert|22|km|mi|abbr=on}} | 2030 |
See also
References
{{Reflist|30em}}
{{Portal bar|Transport}}