This figure represents an increase of more than a million passengers per day compared to 2007, when the ambitious Transantiago project was launched, in which the metro plays an important role in the public transport system serving the city.

The new line will add 26 kilometres (16 mi) and 19 new stations to the Metro network, running along the municipalities of Renca, Cerro Navia, Quinta Normal, Santiago, Providencia, Las Condes and Vitacura.

[9] The idea of constructing an underground railway network in Santiago dates back to 1944 when efforts to improve the chaotic transport system were initiated due to the rapid population growth the city had been experiencing since the early 1930s.

On 24 October 1968, the government of Eduardo Frei Montalva approved the draft submitted by the Franco-Chilean consortium BCEOM SOFRETU CADE, in which the construction of five lines with an extension of approximately 60 kilometres (37 mi) by 1990 was proposed.

On 29 May 1969, works finally began for the construction of the first line, which would link the Civil District and the area of Barrancas (current-day Lo Prado).

Furthermore, studies showed that southeast Santiago was becoming more populated than the north end of the capital, area that was then covered by the planned extensions of the service.

With the election of Ricardo Lagos as President of Chile in 2000, one of his main objectives was an overhaul of the transport system serving the capital.

Along with the new extensions, exchange stations were designed to allow for a better interaction between the urban railways and other means of transport, mainly buses.

On September 8, 2004, the Metro would make another breakthrough when the Mapocho river was crossed underground, with the opening of Patronato and Cerro Blanco stations on Line 2.

On November 30, 2005, the first underground leg of Line 4 from Tobalaba to Grecia, and the viaduct between Vicente Valdés and Plaza de Puente Alto opened to the public.

On November 15, 2005, President Ricardo Lagos announced the extension of Line 1 to the east, from Escuela Militar to Los Dominicos station, in the commune of Las Condes.

In this way, the Metro approached the western sector of the city for the first time, reaching Maipú, the most populated commune in the country after surpassing Puente Alto in 2008.

On January 22, 2019, Line 3 was inaugurated, after 9 years of prospecting and construction [17] and being delayed since the 1980s after the 1985 Algarrobo earthquake and the changing demographics of the city during the '80s and '90s.

At night, after the declaration of a state of emergency by President Sebastián Piñera, several stations of the Metro were destroyed and burned, some of which were attacked again the next day, even though a curfew had been established.

Meanwhile, the Instituto Nacional de Derechos Humanos investigated accusations that the Baquedano station was used as a detention and torture center by police and military.

The judges found no evidence of torture or illegal detentions at the site, but an investigation was launched to rule out any irregular situation.

However, investigations conducted by the National Institute of Human Rights and the Public Prosecutor's Office found no evidence in this regard; in 2020, the allegations were dismissed, and the case was closed.

Upon the reopening of the last two stations (Trinidad and Protectora de la Infancia) on September 25, 2020, the metro system was back to 100% operation.

Line 7 would allow the incorporation of the communes of Renca, Cerro Navia and Vitacura into the Network, also connecting popular neighborhoods with part of the financial and commercial district of the city.

In addition, he announced that Line 4 would be extended by three stations in the southern sector to reach Bajos de Mena in Puente Alto.

Ticket offices, public telephones and metro-network information panels exist in every station; Redbanc, Cirrus and Plus-enabled ATMs, typically provided by either the Banco de Chile company or the BancoEstado national bank, are common.

In higher-traffic stations, there are screens that display MetroTV, featuring additional system information as well as music videos and short news segments.

A Chilean ID or foreign passport allows any Metro customer to freely borrow from a reserve of books and other literature, but a registration is needed first.

Customers may rent a parking space for their bicycles through the Bicimetro network, which opened in 2008 at six stations and is slowly expanding, for a starting cost of $300 (approximately US$0.50) a day.

There are weekly and monthly rental services too, that guarantee a fixed space for the bike (contrary to the daily rent which relies on random free-space).

Various private security agencies have day-to-day responsibility for maintaining order in the metro and deterring petty crime or attempts to board without paying.

The largest transfer stations, such as Tobalaba, also feature depots of the Carabineros de Chile, the national military police force.

Metro travelers are advised to keep a close guard on their belongings, as petty or opportunistic theft is somewhat of a problem in lines that connect some districts to the center of Santiago.

Metro is part of Red Metropolitana de Movilidad, the integrated public transport system that serves the capital using also feeder and main bus routes.

Red works with an integrated fare system, which allows passengers to make bus-bus or bus-metro transfers on a two-hour time limit from the first trip (maximum of two changes) using a contactless smart card called "Bip!