Paris Metro Line 1 (French: Ligne 1 du métro de Paris) is one of the sixteen lines of the Paris Metro. It connects La Défense in the northwest and Château de Vincennes in the southeast. With a length of 16.5 km (10.3 mi), it constitutes an important east–west transportation route within the City of Paris. Excluding Réseau Express Régional (RER) commuter lines, it is the second busiest line on the network with 181.2 million travellers in 2017 or 750,000 people per day on average in Fall 2025.
The line was the network's first to open, with its inaugural section entering service in 1900. It is also the network's first line to be converted from manually driven operation to fully automated operation. Conversion, which commenced in 2007 and was completed in 2011, included new rolling stock (MP 05) and laying of platform edge doors in all stations. The first eight MP 05 trains (501 through 508) went into passenger service on 3 November 2011, allowing the accelerated transfer of the existing MP 89 CC stock to Line 4. The conversion allowed Line 1 to operate as the system's second fully automated line, after Line 14.
A transition to fully automated services was done without major interruption to passenger traffic. The new MP 05 rolling stock was able to operate efficiently alongside the manually-driven MP 89 CC rolling stock until there were enough MP 05 to no longer facilitate the need of the MP 89. Full automation was achieved for evening services in May 2012, with an increase to weekend services by August 2012. As of 15 December 2012, Line 1 is fully automated. The remaining five MP 89 CC trains remained stored on Line 1 near the Fontenay workshops until a new garage for Line 4 was opened south of the new Mairie de Montrouge station in February 2013. Line 1 is currently being extended to Val de Fontenay to make a link with Paris Metro Line 15, RER A, RER E and an extension of Tram 1.
The Parisian metropolitan rail network has its origins in several decades of debate, more or less bizarre projects and tug of war between the State (which was favourable to the interconnection of large rail networks with large undergrounds) and the administration of the City of Paris (which wanted a small-scale network, serving only the inner city with very close stations, effectively prohibiting access to the rolling stock of the large railway companies). The deterioration of traffic conditions in Paris, the example of foreign capitals and the approach of the 1900 Universal Exhibition convinced the authorities to start construction of the metro. The solution proposed by the Mayor of Paris was finally adopted; the State conceded the design and construction of the work to the City of Paris. After the adoption by the municipal council on 20 April 1896 of the network project of Fulgence Bienvenüe and Edmond Huet, the "metropolitan railway" was declared a public utility by a law that became effective 30 March 1898.
This "railway of local interest" with electric traction, with a reduced loading gauge of 2.40 m (7 ft 10 in) wide and standard gauge, intended for the transport of passengers and their hand luggage, includes six lines:
A: Porte de Vincennes – Porte Dauphine;
B: Circular, by the old outer boulevards (Étoile – Nation – Étoile);
C: Porte Maillot – Ménilmontant;
D: Porte de Clignancourt – Porte d'Orléans;
E: Boulevard de Strasbourg (Gare de l'Est) – Pont d'Austerlitz;
F: Cours de Vincennes – Place d'Italie.
Three lines were planned as a possible option: Place Valhubert – Quai de Conti (on the south bank of the Seine), Place du Palais-Royal – Place du Danube and Auteuil – Place de l'Opéra.
Under an agreement of 27 January 1898 between the City and the Compagnie générale de traction, the network concessionaire, the company agreed to put the first three lines into service within eight years following the declaration of public utility. The first detailed traffic studies suggested swapping the termini of lines A and C: the trains on line A would terminate at Porte Maillot, constituting line 1 of the future network, while those on line C, the future line 3, would terminate at Porte Dauphine. It then also becomes possible to send the trains on the circular line to Porte Dauphine, and this terminus is then considered to be the start of line B.
Work on line 1 began on 4 October 1898, as part of an agreement between the Paris administration and the Compagnie du chemin de fer métropolitain de Paris (CMP), which stipulated that the city would build the network infrastructure (tunnels, stations), with the concessionaire building the superstructure (tracks and access to stations).
From November 1898, the Paris administration began preparatory work for the construction of the first line of the metropolitan railway: construction of service tunnels between the line and the Seine for the evacuation of spoil, relocation of the collector sewer on the Rue de Rivoli, and rearrangement of the water pipes. The work on the line itself was carried out in record time: it lasted twenty months and was led by Fulgence Bienvenüe, a bridges and roads engineer, and financed by the city of Paris. The line was divided into eleven lots divided between several companies. Eleven shields (a type of tunnel boring machine) were built for this work and installed under the roadways, with which approximately 2,500 m (8,200 ft) of tunnel were dug, including more than 1,500 m (4,900 ft) by the three Champigneul shields which dug from the Place de la Nation (in both directions) and that of the Porte Maillot. In order to reduce the duration of the construction site, however, the construction also made extensive use of traditional methods of galleries supported by pit props. Cut and cover work was only used for the construction of certain stations and a very small section of tunnel.
On 15 June 1900, Line 1 was handed over by the Paris administration to its operator, la Compagnie du chemin de fer métropolitain de Paris (the Paris Metropolitan Railway Company), which ran its trains to test the line and train personnel.
On 19 July 1900 at 1 p.m., the line was opened to the public between Porte Maillot and Porte de Vincennes to connect the various sites of the Universal Exhibition and serve the events of the 1900 Olympic Games in the Bois de Vincennes. It followed the monumental west-east axis in Paris. The line was inaugurated in a very discreet manner, because the Compagnie du chemin de fer métropolitain de Paris wanted a gradual increase in capacity. Only eight stations were completed and opened at the inauguration, while the other ten were gradually opened between 6 August and 1 September 1900. These eighteen stations were entirely built under the supervision of the engineer Fulgence Bienvenüe. Most of them were 75 m (246 ft) long and their platforms were 4.1 m (13 ft) wide. The external entrance canopies (or edicules) were designed by the emblematic architect of Art Nouveau, Hector Guimard.
Electricity was supplied, from March 1901, by the large power station that the CMP had built in the Bercy district, behind its administration building on the Quai de Bercy, where the RATP house, the company's headquarters, was now located. This plant supplied three-phase current at 5,000 volts 25 hertz, with its eighteen boilers with a heating surface of 244 m2 (2,630 sq ft) and its three 1,500 kW generator sets. Before the Bercy plant was commissioned, electricity was supplied by the companies Le Triphasé (Asnières-sur-Seine) and the Compagnie générale de traction (Moulineaux).