Line 4 or 4 Line may refer to:

Public transport

Asia

Line 4 (Chennai Metro) The Yellow Line or Line 4 is one of the under construction lines of Chennai Metro Phase-II stretching from to . The line will consist of 27 stations, out of which nine will be underground and 18 will be at grade or elevated. The colour code o ...

, or Orange Line, under construction in India *

Busan Metro Line 4 Busan Metro Line 4 () is a rubber-tyred metro line of the Busan Metro network that connects part of Gijang-gun, Busan, and upper Haeundae-gu, Busan, into Dongnae-gu, Busan Korea. It is operated by the Busan Transportation Corporation. Opened on ...

, a rubber-tyred metro line in Busan, South Korea * Manila Light Rail Transit System Line 4, Metro Manila, Philippines *

Line 4 (Mumbai Metro) The Green Line is part of Mumbai Metro rail network for the city of Mumbai, Maharashtra, India. During the construction the line was divided into 3 smaller lines - Line 4 ( to ), Line 4A ( to ), and Line 10( to ). The line also has a proposed s ...

, under early stages of construction * Line 4 (Osaka) or Chūō Line, in Japan *

Seoul Subway Line 4 Seoul Subway Line 4 of the Seoul Metropolitan Subway is a long line crossing from the southwest to the northeast across the Seoul Metropolitan Area. The central section in Seoul City is operated by Seoul Metro with some trains offering throug ...

, a line across the National Capital Area, South Korea *

Sri Petaling Line , , The LRT Ampang Line and the LRT Sri Petaling Line are medium-capacity rail system, medium-capacity light rapid transit (LRT) lines in the Klang Valley, Malaysia. The combined network comprises of tracks with 36 stations and was the ...

, the fourth rapid transit line in Klang Valley, Malaysia *

Zhonghe–Xinlu line The Zhonghe–Xinlu or Orange line (code O) is a metro line in Taipei operated by the Taipei Metro, named after the districts it connects: Zhonghe, Xinzhuang and Luzhou. The line starts at in Zhonghe, passes through central Taipei, then split ...

, a metro line in Taipei, Taiwan

China

Line 4 (Beijing Subway) Line 4 of the Beijing Subway () is a subway line in Beijing's mass transit network. It entered into operation on 28 September 2009, and runs from north to south, parallel and to the west of Line 5, through Haidian, Xicheng, and Fengtai Dis ...

, a subway line in Beijing * Line 4 (Changchun Rail Transit), a metro line in Changchun, Jilin * Line 4 (Changsha Metro), 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 to Xihe in the Longquanyi Longquanyi District () is ...

, a metro line in Chengdu, Sichuan *

Line 4 (Chongqing Rail Transit) Line 4 of Chongqing Rail Transit is a rapid transit line in Chongqing ChongqingPostal Romanization, Previously romanized as Chungking ();. is a direct-administered municipality in Southwestern China. Chongqing is one of the four direct-a ...

, a metro line in Chongqing *

Line 4 (Dongguan Rail Transit) Line 4 of the Dongguan Rail Transit () is a planned rapid transit line in Dongguan, Guangdong Province, China. It has a planned 12 stations and its Y-shaped design means that it has 3 terminating stations: Huangjiang Center (interchange with Lin ...

, a planned metro line in Dongguan, Guangdong * Line 4 (Fuzhou Metro), a line under construction in Fuzhou, Fujian *

Line 4 (Guangzhou Metro) Line 4 of the Guangzhou Metro is a south-north line on the system that runs between and stations, spanning a total of with 24 stations (while not yet in service). The sections of the line from Xinzao to Huangcun, Feishajiao to Nansha Passeng ...

, a metro line in Guangzhou, Guangdong *

Line 4 (Hangzhou Metro) Line 4 of the Hangzhou Metro () is a rapid transit line in Hangzhou. Description Phase 1 Phase 1 of the line started operation since 2015. Running northeast–southwest, the line connects Hangzhou East railway station, Qianjiang New City and Binj ...

, a metro line in Hangzhou, Zhejiang *

Line 4 (Hefei Metro) Hefei Metro Line 4 is a metro line in Hefei, Anhui, China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by po ...

, a metro line in Hefei, Anhui *

Line 4 (Kunming Metro) Line 4 is a rapid transit line on the Kunming Metro, serving the city of Kunming, China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it ...

, a metro line in Kunming, Yunnan * Line 4 (Nanchang Metro), a metro line in Nanchang, Jiangxi *

Line 4 (Nanjing Metro) Line 4 is an east-west line on the Nanjing Metro, running from to . It consists of 18 stations and spans a total of . The line color is purple, and it first opened on January 18, 2017. Opening timeline Station list Future plans The seco ...

, a metro line in Nanjing, Jiangsu *

Line 4 (Nanning Metro) Line 4 of the Nanning Metro is a rapid transit line in Nanning Nanning; is the capital of the Guangxi, Guangxi Zhuang Autonomous Region in South China, southern China. It is known as the "Green City (绿城) " because of its abundance of ...

, a metro line in Nanning, Guangxi *

Line 4 (Ningbo Rail Transit) Line 4 of Ningbo Rail Transit ( zh, s=宁波轨道交通4号线) is a rapid transit line in Ningbo. It starts from Cicheng Town, Jiangbei District, Ningbo, Jiangbei District, and ends near Ningbo International Conference Center in Yinzhou District ...

, a metro line in Ningbo, Zhejiang *

Line 4 (Qingdao Metro) Line 4 of Qingdao Metro is a rapid transit line in Qingdao, Shandong, China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list ...

, a metro line in Qingdao, Shandong *

Line 4 (Shanghai Metro) Line 4 is a orbital (metro), loop line of the Shanghai Metro network. The older rolling stock 04A01 carry a bright purple colour belt to differentiate them from Line 3 (Shanghai Metro), Line 3 trains which share a portion of its route, while the n ...

, a metro line in Shanghai *

Line 4 (Shenzhen Metro) Line 4 of the Shenzhen Metro, formerly branded as the Longhua line, runs South–North from to . The line serves Futian District and Longhua District of Shenzhen. The line originally used 4-car trains, making it extremely crowded; although it ...

, a metro line in Shenzhen, Guangdong *

Line 4 (Suzhou Metro) Line 4 is a line of the Suzhou Metro. It runs in a north–south alignment from Longdaobang station in Xiangcheng District's the northern suburbs, to the canal town of Tongli Tongli, alternately Tong-Li (; Wu: Don li, ) is a town in Wu ...

, a metro line in Suzhou, Jiangsu *

Line 4 (Tianjin Metro) Line 4 of Tianjin Metro () is a metro line in Tianjin Tianjin is a direct-administered municipality in North China, northern China on the shore of the Bohai Sea. It is one of the National Central City, nine national central cities, with a tota ...

, a metro line in Tianjin *

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 train ...

, a metro line in Wuhan, Hubei *

Line 4 (Wuxi Metro) Line 4 of the Wuxi Metro () is a rapid transit line in Wuxi Wuxi ( zh, s=无锡, p=Wúxī, ) is a city in southern Jiangsu, China. As of the 2024 census, it had a population of 7,495,000. The city lies in the southern Yangtze delta and border ...

, a metro line in Wuxi, Jiangsu *

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 timelin ...

, a metro line in Xi'an, Shaanxi * Line 4 (Zhengzhou Metro), a metro line in Zhengzhou, Henan

Europe

Line 4 (Athens Metro) Line 4 of the Athens Metro is a future line that will run from Alsos Veikou to Goudi. Construction of the line started in mid to late-2021 and is scheduled to be completed in 2029 but is more realistically estimated to remain under construction ...

, a proposed metro line in Greece * Barcelona Metro line 4, 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), 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, in length and consisting of ten stations, connects t ...

, a line in Hungary *

Line 4 (Madrid Metro) Line 4 is a rapid transit line of the Madrid Metro connecting the west and center of Madrid with the said city's northeastern end, running between Argüelles and Pinar de Chamartín. It consists of a total of 23 narrow-gauge stations with 60-met ...

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

Paris Métro Line 4 Line 4 () is one of the sixteen lines of the Paris Métro rapid transit system and one of its three fully automated lines. Situated mostly within the boundaries of the City of Paris, it connects Porte de Clignancourt (Paris Métro), Porte de C ...

, a line in France *

Paris Tramway Line 4 Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

, a tram-train line just outside the limits of Paris proper *

Line 4 (Saint Petersburg Metro) Line 4 of the Saint Petersburg Metro, also known as ''Lakhtinsko-Pravoberezhnaya Line'' () or ''Orange Line'', is a rapid transit line in Saint Petersburg, Russia, which connects city centre with the south-east districts on the right bank of the ...

, a metro line in Saint Petersburg, Russia *

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

, 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 Line 4 Sheppard is the newest and shortest rapid transit line of the Toronto subway system, operated by the Toronto Transit Commission (TTC). It opened on November 22, 2002, and has five metro station, stations along of track, which is built ...

, a subway line in Toronto, Canada *

Yellow Line (Montreal Metro) The Yellow Line (, ), also known as Line 4 (), is one of the Montreal Metro's four routes operating in Montreal, Quebec, Canada. Built to serve the crowds of the Expo 67 exhibition, the line now forms a key link between Downtown Montreal, the S ...

, formerly known as Line 4, in Canada * Line 4 of the Guadalajara urban rail system, Mexico * Mexico City Metro Line 4, a rapid transit line in Mexico City *

Mexico City Metrobús Line 4 The Mexico City Metrobús Line 4 is a bus rapid transit line in the Mexico City Metrobus. It operates between Colonia Buenavista, in central Mexico City and the Mexico City International Airport in the Venustiano Carranza, Mexico City, Venustiano ...

, a bus rapid transit line in Mexico City * Route 4 (Baltimore), a bus route in the United States * No. 4 Line (Baltimore streetcar), 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 (New York City Subway), 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. Th ...

, a subway line in New York City * 4 (Los Angeles Railway), streetcar lines in Los Angeles * 4 Line (Sound Transit), a planned light rail line in Washington State *

Line 4 (O-Train) Line 4 (), also known as the Airport Link (), is a diesel light rail line on the O-Train network in Ottawa, Ontario. The line provides a connection between Line 2 (also known as the Trillium Line) at South Keys station to Ottawa Macdonald– ...

, the Airport Link (Blue Line) of Ottawa's O-Train

South America

Line 4 (Rio de Janeiro) Line 4 (Yellow) of the Rio de Janeiro Metro is the third metro line built in the city of Rio de Janeiro. It was completed on 30 July 2016, connecting the Barra da Tijuca neighbourhood in the West Zone, passing under São Conrado and Rocinha, to I ...

, a line under construction in Brazil *

Line 4 (São Paulo Metro) Line 4 (Yellow) () is one of the six lines that make up the São Paulo Metro and one of the thirteen lines that make up the São Paulo Metropolitan Rail Transportation Network. Originally called Southeast-Southwest Line, the line goes from Vila S ...

, a line under construction in Brazil *

Santiago Metro Line 4 Santiago Metro Line 4 is one of the seven lines that currently make up the Santiago Metro network in Santiago, Chile. It has 23 stations and of track. The line intersects with Santiago Metro Line 1, Line 1 at Tobalaba metro station, Tobalaba, wit ...

, in Chile *

Santiago Metro Line 4A Santiago Metro Line 4A is one of the seven lines that currently make up the Santiago Metro network in Santiago, Chile. It has six stations and of track. The line intersects with Santiago Metro Line 2, Line 2 at La Cisterna metro station, La Cist ...

, in Chile

Measurement

*4-line, obsolete measure in Line *4-line, 12.17x44mm ammunition or a rifle which fires it