The Buenos Aires Underground (), locally known as Subte (), is a rapid transit system that serves the area of the city of Buenos Aires, Argentina. The first section of this network (Plaza de Mayo–Plaza Miserere) opened in 1913, making it the 13th earliest subway network in the world and the first underground railway in Latin America, the Southern Hemisphere, and the Spanish-speaking world, with the Madrid Metro opening nearly six years later, in 1919. As of 2026, Buenos Aires is the only Argentine city with a metro system.
Currently, the underground network's six lines—A, B, C, D, E, and H—comprise of routes that serve 90 stations. The network is complemented by the Line P, an 18 station light rail line. Traffic on subterranean lines moves on the left because Argentina drove on the left at the time the system opened. Over a million passengers use the network, which also provides connections with the city's extensive commuter rail and bus rapid transport networks.
The network expanded rapidly during the early decades of the 20th century; by 1944, its main routes were completed, with the addition of its newest line occurring as late as 2007. The pace of expansion fell sharply after the Second World War. In the late 1990s, expansion resumed at a quicker pace, and four new lines were planned for the network. Despite this, the network's expansion has been largely exceeded by the transportation needs of the city and is said to be overcrowded. In 2015, two modernization plans were presented: City of Buenos Aires Law 670, proposing the creation of 3 new lines (F, G, and I), and the PETERS plan, wherein 2 lines were to be created and the I line would have been postponed for future expansion, plus several other route amendments. However, since 2019, there have been no expansions under construction, for the first time in half a century.
The entire network was nationalized in 1939, remaining in state hands and operation until the mid-1990s, when it entered into a concession model. The previously state-operated lines were offered as 20-year concessions to interested private parties; the two complementary lines were also included in this privatization, and all were operated by Metrovías from 1995 to 2021, though the network and rolling stock remain the property of the City of Buenos Aires.
In December 2021, "Emova Movilidad S.A." took over the concession of the Buenos Aires Underground for 12 years. Emova is also part of the Roggio Group, associated with former operator Metrovías.Subte: a partir de mañana Emova Movilidad S.A. se hará cargo de la operación y mantenimiento on GCBA, 30 Nov 2021
History The Subte opened in 1913, becoming the 13th underground system in the world, as well as the first in Latin America, the Southern Hemisphere and the Hispanophone world,Se cumplieron 100 años del primer viaje en subte – Ambito, 1 December 2013. followed by the Madrid Metro in 1919.La historia de 100 años del primer subte de América del Sur – Perfil, 1 December 2013.Background and Inauguration in 1919 – Metro de Madrid The creation of the underground was part of a number of other urban transformations. A system of public water and sewage was first completed in 1886 and expanded in the subsequent decades, and many streets were paved as part of this same urban renewal.
The underground network was originally built and operated by three separate private companies and later nationalized in 1939. In 1952 it was absorbed by a unified state administration, in 1963 it became the property of a newly founded company, which changed hands in 1979. The Subte then entered into a concession model in the mid-1990s through which private sector parties were to submit bids to execute investment plans "designed and funded" by the state, while implemented by the concessionaire. All the Underground lines, along with the Urquiza Line and Premetro were offered as 20-year concessions to interested private parties. By 1995, Metrovías took over the Subte under a $395 million plan.
Early days
Discussions on the need to build an underground transportation system in Buenos Aires began in the late nineteenth century, alongside the tramway system, which was one of the most extensive in the world at the time. The first trams appeared in 1870, and by about 1900 the system was in a crisis exacerbated by the monopolization of the lines, which had concentrated under the ownership of fewer companies during the electrification of the system.
In this context, the first proposals for the building of an underground system were made, along with requests for government grants: first, in 1886, and several more in 1889. However, the Ministry of Interior (Ministerio del Interior, in Spanish) denied the city administration the power to license building in the city's subsoil and for this reason, subsequent drafts were submitted directly to this ministry.L. Contreras y N. Tkach (2007), Buenos Aires y el Transporte, p.72, Colección cuadernos educativos, Ministerio de Cultura de la Ciudad de Buenos Aires. In 1894, when it was decided to construct the Congress building in its present location, the underground idea was revived, since it would shorten the travel time between the Casa Rosada and the Congress. In 1896 Miguel Cané, former mayor of Buenos Aires (1892–1893), expressed the need to build an underground railway similar to the one in London
There were numerous proposals at the time to build an electric aerial tramway, with one such line to go down the Avenida de Mayo. One proposal was the 1889 Le Tellier proposal, which envisioned multiple lines running along the city's wider avenues with the trams moved using cables and would hang from steel rails fixed to steel and iron posts positioned in intervals. The lines would take 24 months to build, and construction would commence 3 months after their approval by the Argentine National Congress, a decision which was ultimately not taken, favoring instead an underground tramway.
The first Underground line was opened on 1 December 1913 and was built by the Anglo-Argentine Tramways Company (AATC), which had been given permission to build in 1909. That line was made up of one of the existing sections of Line A, linking the stations of Plaza de Mayo and Plaza Miserere.El primer subte – La Nacion, 22 December 2010. 170,000 passengers took part in the line's first trip. On 1 April 1914 the line was to expand to Río de Janeiro station and on 1 July was extended to Primera Junta Station.
In 1912, the Lacroze Hermanos company won a concession to build another Underground line. The company was a competitor to the Anglo-Argentine company, operating tramways in Buenos Aires as well as the Buenos Aires Central Railway, which later became part of the Urquiza Line. Construction began in 1927, and this line became Line B when it was inaugurated on 17 October 1930. During 17–18 December, 380,000 passengers travelled on the line's then 32 cars. The line was originally intended to continue above ground, with the current Federico Lacroze station to be the central terminal of the Buenos Aires Central Railway (today the General Urquiza Railway), however nowadays the overground service forms part of the Urquiza Line instead.Un paseo por la historia del subte – Publicable, 22 November 2014.
By the 1920s, the Argentine government was dissatisfied with the lack of progress the AATC (which enjoyed a near-monopoly on the city's tramways by this point) had made in expanding the rest of the network and thus revoked its right to build any more lines in 1930, seeking instead another company to do so. By this point, the AATC had only built 48 meters of what is today Line C, a line which would link two of the city's most important rail terminals (Constitución and Retiro) together. In 1933 a third company, the Hispano-Argentina Company of Public Works and Finances (Compañía Hispano–Argentina de Obras Públicas y Finanzas (CHADOPyF), in Spanish) began construction of the other Underground lines.Antecedentes, Inicios, Desarrollo de la red y Líneas (in Spanish - archive). Retrieved 2010-11-03. Line C's first section, Constitución railway station-Diagonal Norte, was inaugurated on 9 November 1934 by Agustín P. Justo, then President of Argentina.
CHADOPyF opened Line D in 1937, from Catedral through Tribunales; with Line E following later in 1944, from Constitución to San Juan y Urquiza, later joining with Boedo station. By this point the advent of the Second World War had slowed expansion significantly, but the network was in length with each of the three companies – unusually for an underground network – continuing to run their respective lines, which were financed entirely with private capital, unlike the country's railways which had been largely dependent on subsidies.
Nationalisation
The entire network was centralized and nationalized in 1939 under the management of the Transport Corporation of Buenos Aires (CTCBA) and the lines were given their current lettered naming scheme, from A to D in the order in which the lines were opened. In 1952, the CTCBA was absorbed by the Buenos Aires Transport General Administration (AGTBA), and in 1963, the administration was dissolved and the underground network became the property of the Subterráneos de Buenos Aires company (SBA).
In the early years of nationalization, interchanges were provided between the lines previously belonging to the three different companies that built them (AATC, CHADOPyF and Lacroze) since previously only the CHADOPyF lines (C, D and E) had formal connections between them. However, the rate of expansion of the network during this period had slowed considerably and only one station was opened during the 1970s.
Four different long-term expansion proposals were put forward between 1964 and 1991 which all proposed adding numerous lines to the network as well as extending the existing ones. Given the political instability characteristic of Argentina during this time, none of these proposals came to fruition, though aspects of them have been incorporated into contemporary expansion plans. One additional proposal put forward in 1973 saw the unification of the city's commuter rail lines through tunnels and incorporated into the Buenos Aires Underground, and while this was also shelved, it was included in the Red de Expresos Regionales proposal.Plan Estratégico y Técnico para la Expansión de la Red de Subtes de Buenos Aires – Buenos Aires Ciudad, 30 September 2015.
During the 1960s and 70s, efforts were primarily concentrated on Line E, which was re-routed from its terminus at Constitución to the centre of the city at the Plaza de Mayo in an attempt to boost passenger figures, something which proved to be successful. The segment was opened by president Arturo Illia in 1966 and Spain offered CAF-General Eléctrica Española trains in order to cancel part of the debt it had accrued with Argentina; trains which continue to serve on the line today. The line was extended westward to José María Moreno in a project that began in 1969 and opened in 1973.
In 1979, SBA became Subterráneos de Buenos Aires Sociedad del Estado (SBASE) under Buenos Aires mayor Osvaldo Cacciatore of the National Reorganisation Process military junta. After a long period of stagnation, the Underground began to be expanded again with Lines B and E within the scope of these plans, though only the extension of Line E was commenced and completed before the transition to democracy where expansion was once again stalled. During this time, four Premetro feeder lines were planned leading out from the western termini of Lines D and E as well as one in Puerto Madero, however only Line E2 was completed in 1987 and these plans were scrapped in 1994 when operation of the Underground changed hands.
Privatisation