[7] With the Metro and the newer driverless, steel-wheeled Réseau express métropolitain, Montreal has one of North America's largest urban rapid transit systems, attracting the second-highest ridership per capita behind New York City.

[8] Urban transit began in Montreal in 1861 when a line of horse-drawn cars started to operate on Craig (now St-Antoine) and Notre-Dame streets.

The gradual return to financial health during the 1920s brought the MTC project back and attracted support from the premier of Quebec.

[13] In 1953, the newly formed public Montreal Transportation Commission replaced streetcars with buses and proposed a single subway line reusing the 1944 plans and extending it all the way to Boulevard Crémazie, right by the D'Youville maintenance shops.

[15] This would be the last missed opportunity, for the re-election of Jean Drapeau as mayor and the arrival of his right-hand man, Lucien Saulnier, would prove decisive.

From August 1, 1960, many municipal services reviewed the project and on November 3, 1961, the Montreal City Council voted appropriations amounting to $132 million ($1.06 billion in 2016) to construct and equip an initial network 16 kilometres (9.9 mi) in length.

It was to use Canadian National Railway (CN) tracks passing under the Mount Royal to reach the northwest suburb of Cartierville from the city centre.

The railway, already used for a commuter train to the North Shore at Deux-Montagnes, was completely renovated in the early 1990s and effectively replaced the planned third line.

The success of the Metro increased the pressure to extend the network to other populated areas, including the suburbs on the Island of Montreal.

Faced with these soaring costs, the Government of Quebec declared a moratorium May 19, 1976, to the all-out expansion desired by Mayor Jean Drapeau.

The mayors of the MUC, initially reluctant, accepted this plan when Quebec promised in February 1981 to finance future extensions fully.

RTM now operates Montreal's commuter rail and metropolitan bus services, and is the second busiest such system in Canada after Toronto's GO Transit.

Announced in 1998 by the STCUM,[26][27] the project to extend Line 2 (Orange) past the Henri-Bourassa terminus to the city of Laval, passing under the Rivière des Prairies, was launched March 18, 2002.

Built by CDPQ Infra, part of the Quebec pension fund Caisse de dépôt et placement du Québec, the line will eventually run north-south across Montreal, with interchanges with the Metro at Gare Centrale (Bonaventure), McGill and Édouard-Montpetit.

[37] On April 9, 2018, premier of Quebec Philippe Couillard and Prime Minister Justin Trudeau announced their commitment to fund and complete the extension, then planned to open in 2026.

The Metro fares are fully integrated with the Exo commuter rail system, which links the metropolitan area to the outer suburbs via six interchange stations (Bonaventure, Lucien-L'Allier, Vendôme, De la Concorde, Sauvé, and Parc) and the Réseau express métropolitain (REM), which opened in August 2023.

Montreal has one of North America's busiest public transportation systems with, after New York, the largest number of users compared to its population.

For example, 74% of the rolling stock replacement cost is paid for by Quebec while 33% of the bill for upgrades to ventilation structures is covered by the federal government.

Some of the most important works in the Metro include the stained-glass window at Champ-de-Mars station, the masterpiece of major Quebec artist Marcelle Ferron; and the Guimard entrance at Square-Victoria-OACI station, largely consisting of parts from the famous entrances designed for the Paris Métro, on permanent loan[66] since 1966 by the RATP to commemorate its cooperation in constructing the Metro.

North American cities building metro systems in the 1960s and 1970s (Washington, D.C., San Francisco and Atlanta) were in search of modern rolling stock that not only best fit their needs but also encompassed a change in industrial design that focused on the aesthetics and performances.

[82] The claim, stated by the STM, is that with the Metro being built entirely underground, air conditioning would heat the tunnels to temperatures that would be too hot to operate the trains.

Formerly Orange Formerly 423[90] (71 trainsets) Montreal's Metro trains are made of low-alloy high-tensile steel, painted blue with a thick white band running lengthwise.

The train then uses composite brake blocks made of yellow birch injected with peanut oil to bring it to a complete stop.

[96] Rubber tires on the Montreal Metro transmit minimal vibration and help the cars go uphill more easily and negotiate turns at high speeds.

However, the advantages of rubber tires are offset by noise levels generated by traction motors which are noisier than the typical North American subway car[according to whom?

[98] The three tones are essentially the same as the iconic first three trumpet notes from Aaron Copland's musical piece "Fanfare for the Common Man".

Nine-car trains draw large currents of up to 6,000 amperes,[citation needed] requiring that all models of rolling stock have calibrated traction motor control systems to prevent power surges, arcing and breaker tripping.

The only repair facility for the Montreal Metro is the Atelier Plateau d'Youville, located at the intersection of Crémazie (part of Trans-Canada Highway) and Saint-Laurent Boulevards.

[115] A 2006 study rejected the possibility and cost of an extension from Lionel-Groulx station to the City of Brossard on the south shore of Montreal as an alternative to the proposed light rail project in the Champlain bridge corridor.

[117] On May 26, 2011, Vaillancourt, after the successful opening of highway 25 toll bridge in the eastern part of Laval, proposed that Laval develop its remaining territories with a transit-oriented development (TOD) build around five new Metro stations: four on the west branch (Gouin, Lévesque, Notre-Dame and Carrefour) of the Orange Line and one more on the east branch (De l'Agora).