Line 4 or 4 Line may refer to:

Public transport

Asia

Line 4 (Chennai Metro) The Orange Line or Line 4 is one of the three lines of Chennai Metro, Phase 2 Project . The under construction line stretches from to . The line will consist of 27 stations, out of which 9 are underground and 18 are elevated. Phase II E. ...

, or Orange Line, under construction in India * Busan Metro Line 4, a rubber-tyred metro line in Busan, South Korea * Kolkata Metro Line 4 or Noapara Barasat Line, under construction in India * Manila Light Rail Transit System Line 4, Metro Manila, Philippines *

Line 4 (Mumbai Metro) Green Line 4 of the Mumbai Metro, currently under construction, is part of the metro system for the city of Mumbai, India and is being developed by MMRDA and a consortium of international companies. The line is planned to be fully elevated, an ...

, under early stages of construction * Line 4 (Osaka) or Chūō Line, in Japan * Seoul Subway Line 4, a line across the National Capital Area, South Korea * Sri Petaling Line, the fourth rapid transit line in Klang Valley, Malaysia * Zhonghe–Xinlu line, a metro line in Taipei, Taiwan

China

* Line 4 (Beijing Subway), a metro line in Beijing *

Line 4 (Changchun Subway) Line 4 of the Changchun Rail Transit () is a grade separated light rail line in Changchun, running from north to south. Although it uses extended low floor LRVs, the line operates more like a metro, being entirely separate from traffic, simila ...

, a metro line in Changchun, Jilin *

Line 4 (Changsha Metro) Line 4 of the Changsha Metro () is a rapid transit line in Changsha Changsha (; ; ; Changshanese pronunciation: (), Standard Chinese, Standard Mandarin pronunciation: ) is the Capital city, capital and the largest city of Hunan Province o ...

, a metro line in Changsha, Hunan *

Line 4 (Chengdu Metro) Line 4 of the Chengdu Metro () is the third line to enter revenue service on the metro network in Chengdu, Sichuan. Line 4 runs in an east-west direction, stretching from Wansheng in Wenjiang Wenjiang District () is one of 11 urban districts of ...

, a metro line in Chengdu, Sichuan * Line 4 (Chongqing Rail Transit),a metro line in Chongqing * Line 4 (Dongguan Rail Transit), a planned subway line * Line 4 (Fuzhou Metro), a line under construction * Line 4 (Guangzhou Metro), a metro line in Guangzhou, Guangdong * Line 4 (Hangzhou Metro), a metro line in Hangzhou, Zhejiang * Line 4 (Nanjing Metro), a metro line in Nanjing, Jiangsu * Line 4 (Ningbo Rail Transit), a rapid transit line in Ningbo, Zhejiang * Line 4 (Shanghai Metro), a metro line in Shanghai * Line 4 (Shenzhen Metro), a metro line in Shenzhen, Guangdong * Line 4 (Suzhou Rail Transit), a metro line in Suzhou, Jiangsu *

Line 4 (Wuhan Metro) The Line 4 of Wuhan Metro () is the third line in Wuhan Metro system, and it will be the second metro line crossing the Yangtze river in Wuhan. It is colored grass-green, which is the identifying color of this line, which would appear on its tr ...

, a metro line in Wuhan, Hubei * Line 4 (Wuxi Metro), a line under construction *

Line 4 (Xi'an Metro) Line 4 of Xi'an Metro () is a metro line running from north to south, in Xi'an, Shaanxi Province, China. It was opened on 26 December 2018. The line is in length with 29 stations. The line is colored Tiffany Blue on system maps. Opening timeline ...

, a rapid transit line

Europe

* Line 4 (Athens Metro), a proposed metro line in Greece *

Barcelona Metro line 4 Line 4, also known as Trinitat Nova – La Pau, usually called "línia groga" (yellow line), is a line in the Barcelona Metro network operated by TMB, and part of the ATM fare-integrated transport network. It serves the northern districts of t ...

, a line in Spain *

Rodalies Barcelona line 4 The R4 is a line of Rodalies de Catalunya's Barcelona commuter rail service, operated by Renfe Operadora. It runs northwards from the northern limits of the province of Tarragona to Barcelona, passing through the inland Alt Penedès region. The ...

, a commuter railway in Spain * Line 4 (Metro Bilbao), a proposed line *

Line 4 (Bucharest Metro) M4 is one of the five lines of the Bucharest Metro. It is currently long and runs from Gara de Nord to Străulești, following the Griviței and Bucureștii Noi avenues. History Construction of the line started in September 1989, shortly befor ...

, a line in Romania *

Line 4 (Budapest Metro) Line 4 (officially: South Buda–Rákospalota (DBR) Line, Metro 4 or M4, and unofficially: Green Line) is the fourth line of the Budapest Metro. It opened on 28 March 2014. The first section, 7.4 km in length and consisting of ten stations, ...

, a line in Hungary *

Line 4 (Madrid Metro) Line 4 is a rapid transit line of the Madrid Metro containing 23 stations. Originally opened in 1944, the line has been extended many times over the years and is now one of the busiest lines in the Madrid system. History Line 4 originally opened ...

, a line in Spain *

Line 4 (Milan metro) Line 4 is an underground rapid transit line in Milan, Italy, part of the Milan Metro. The line color is blue. The first section opened on 26 November 2022 and the rest of the line expected to open by 2023. Once completed, the line will be lo ...

, an underground rapid transit line under construction in Italy * Line 4 (Moscow Metro), a metro line in Moscow, Russia * Paris Métro Line 4, a line in France *

Paris Tramway Line 4 Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Sin ...

, a tram-train line just outside the limits of Paris proper * Line 4 (Saint Petersburg Metro), a metro line in Saint Petersburg, Russia *

U4 (Vienna U-Bahn) Line U4 is a line on the Vienna U-Bahn metro Metro, short for metropolitan, may refer to: Geography * Metro (city), a city in Indonesia * A metropolitan area, the populated region including and surrounding an urban center Public transpo ...

, a line in Austria

Oceania

* Eastern Suburbs and Illawarra Line, coded T4, coloured navy, a train line in Sydney, New South Wales.

North America

* Line 4 Sheppard, a subway line in Toronto, Canada * Yellow Line (Montreal Metro), formerly known as Line 4, in Canada * Mexico City Metro Line 4, a rapid transit line in Mexico City *

Route 4 (Baltimore) The Maryland Transit Administration (MTA) is a state-operated mass transit administration in Maryland, and is part of the Maryland Department of Transportation. The MTA operates a comprehensive transit system throughout the Baltimore-Washingto ...

, a bus route in the United States *

No. 4 Line (Baltimore streetcar) Route 15 is a bus route operated by the Maryland Transit Administration in Baltimore and its suburbs. The line currently runs from Security Square Mall, Westview Mall, Windsor Hills, or Walbrook Junction (all in West Baltimore or Baltimore C ...

, replaced by MTA Maryland Route 15 *

4 (New York City Subway service) The 4 Lexington Avenue Express is a rapid transit service in the A Division of the New York City Subway. Its route emblem, or "bullet", is colored since it uses the IRT Lexington Avenue Line in Manhattan. The 4 operates at all times. Daytime s ...

, a subway line in New York City * 4 (Los Angeles Railway), streetcar lines in Los Angeles

South America

Line 4 (Rio de Janeiro) Line 4 (yellow line) is a line of the Rio de Janeiro Metro. It was completed on 30 July 2016, connecting Barra da Tijuca neighbourhood in the West Zone, passing under São Conrado and Rocinha, to Ipanema. All stations are underground, but when arr ...

, a line under construction in Brazil * Line 4 (São Paulo Metro), a line under construction in Brazil * Santiago Metro Line 4, in Chile * Santiago Metro Line 4A, in Chile

Measurement

*4-line, obsolete measure in

Line Line most often refers to: * Line (geometry), object with zero thickness and curvature that stretches to infinity * Telephone line, a single-user circuit on a telephone communication system Line, lines, The Line, or LINE may also refer to: Arts ...

*4-line,

12.17x44mm 1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. ...

ammunition or a rifle which fires it