View source for Paris Métro Line 4

{{Short description|Subway route in the French capital}}
{{expand French|Ligne 4 du métro de Paris|topic=transport|date=April 2015}}
{{No footnotes|date=January 2025}}
{{Use dmy dates|date=July 2020}}
{{Infobox Paris Metro line
| logo          = [[File:Metro-M.svg|30px]] [[File:Paris m 4 jms.svg|30px]]
| box_width     = 350px
| image         = MP89 CA 03 et CC52.jpg
| image_caption = MP 89CA and CC arriving at [[Cité (Paris Métro)|Cité]].
| line_color    = #{{rcr|Paris Métro|4}}
| text_color    = white
| line_name     = Line 4
| network       = [[Paris Métro]]
| locale        =
| year_opened   = 1908
| terminus      = [[Porte de Clignancourt (Paris Métro)|Porte de Clignancourt]]<br />[[Bagneux–Lucie Aubrac (Paris Métro)|Bagneux-Lucie Aubrac]]
| operator_org  = [[Régie autonome des transports parisiens|RATP]]
| conducting_system = Automated (SAET)
| rolling_stock = [[MP 89]]CA<br /><small> (21 trains in operation as of 5 June 2023)</small><br /> [[MP 05]]<br /><small> (11 trains in operation as of 10 February 2023)</small><br /> [[MP 14 (Paris Métro)|MP 14]]<small><br /> (18 trains in operation as of 12 February 2024)</small>
| number_stations = 29
| length        = 13.9
| gauge = {{RailGauge|sg|allk=on}}<br />between [[roll way]]s
| electrification = 750 [[Volt|V]] [[Direct current|DC]], [[guide bar]]s on either side of the track
| route_time    =
| dist_between_stations =
| passengers_per_year = 171,000,000
| traffic_rank = 2nd/16
| connecting_lines = {{br separated entries|{{rint|paris|m}} {{rint|paris|m|1}} {{rint|paris|m|2}} {{rint|paris|m|3}} {{rint|paris|m|5}} {{rint|paris|m|6}} {{rint|paris|m|7}} {{rint|paris|m|8}} {{rint|paris|m|9}} {{rint|paris|m|10}} {{rint|paris|m|11}} {{rint|paris|m|12}} {{rint|paris|m|13}} {{rint|paris|m|14}}|{{rint|paris|r}} {{rint|paris|r|A}} {{rint|paris|r|B}} {{rint|paris|r|C}} {{rint|paris|r|D}} {{rint|paris|r|E}}|{{rint|paris|i|}} {{rint|paris|i|H}} {{rint|paris|i|K}} {{rint|paris|i|N}} {{rint|paris|i|P}}|{{rint|paris|t}} {{rint|paris|t|3a}} {{rint|paris|t|3b}}}}
| map        = {{Paris Métro Line 4}}
}}

'''Line 4''' ({{IPA|fr|liɲᵊ katʁᵊ}}) 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 Clignancourt]] in the north and [[Bagneux–Lucie Aubrac (Paris Métro)|Bagneux-Lucie Aubrac]] in the south, travelling across the heart of the city. Until its southern terminus was changed from [[Porte d'Orléans (Paris Métro)|Porte d'Orléans]] to [[Mairie de Montrouge (Paris Métro)|Mairie de Montrouge]] in 2013, the line was sometimes referred to as the Clignancourt – Orléans Line. At {{convert|13.9|km|mi|abbr=on}} in length, it connects with all Paris Métro lines apart from the very short [[Paris Métro Line 3bis|3bis]] and [[Paris Métro Line 7bis|7bis]] branch lines, as well as with all 5 [[Réseau Express Régional|RER]] express lines. It also serves three of the Paris Railway stations, [[Gare du Nord]], [[Gare de l'Est]], and [[Gare Montparnasse]]. It is the second-busiest Métro line after [[Paris Métro Line 1|Line 1]], carrying over 154&nbsp;million passengers in 2004.

Line 4 was the first line to connect to the south side of the [[River Seine]], through an underwater tunnel built between 1905 and 1907. Line 4 long ran the oldest cars still in service on the system, the [[MP 59]]. They used [[rheostat]]s to dissipate the braking power through resistance and made it the hottest line in the system. Those trains were withdrawn from service during the course of 2011 and 2012 after 45 years (with some being in service for 50 years). They were replaced by the [[MP 89|MP 89 CC]] stock transferred from [[Paris Métro Line 1|Line 1]], once new driverless trains made those redundant on that line. ''(From [[:fr:Ligne 4 du métro de Paris]])''.

In 2013, Line 4 was extended for the first time since its initial construction, into the southern suburbs of [[Montrouge]]. The line was further extended to [[Bagneux–Lucie Aubrac (Paris Métro)|Bagneux–Lucie Aubrac]] in 2022, connecting to the future [[Grand Paris Express]].<ref name=":0">{{Cite web|last=Lenhardt|first=Marjorie|date=2022-01-13|title=Après 45 ans d'attente, la ligne 4 du métro arrive «enfin» à Bagneux !|url=https://www.leparisien.fr/info-paris-ile-de-france-oise/transports/apres-45-ans-dattente-la-ligne-4-du-metro-arrive-enfin-a-bagneux-13-01-2022-3YL2PTI7Y5A3RANWCQJ4W3UB7M.php|access-date=2022-01-13|website=[[Le Parisien]]|language=fr-FR}}</ref> The line has been retrofitted for full automation, with the first automated trains commencing service on 12 September 2022.<ref>{{Cite web|title=[SYMBIOZ] - Forum - Prolongement & automatisation de la ligne 4|url=https://www.symbioz.net/forum/ouragan/messages.php?topic=3891&page=122|access-date=2021-02-15|website=www.symbioz.net}}</ref>

==History==
===Chronology===
* '''21 April 1908:''' A first section of the line was inaugurated to the north of the [[Seine]] between Porte de Clignancourt and Châtelet.
* '''30 October 1909:''' A second section of the line was inaugurated south of the Seine between Porte d'Orléans and Raspail.
* '''9 January 1910:''' Both sections were linked by a new tunnel between Châtelet and Raspail.  Line 4 was the first line crossing the Seine river underground.
* '''1967:''' The rails were converted in order to cater for rubber-tired trains. The MP 59 rolling stock replaced the steel-wheeled Sprague-Thomson stock.
* '''3 October 1977:''' The station Les Halles was rebuilt to interchange with the new RER network.
* '''23 May 2011:''' Cascading of MP 59 to MP 89CC rolling stock began.
* '''21 December 2012:''' The last MP 59 (#6021) was withdrawn after 45 years of service on Line 4.
* '''23 March 2013:''' Extension south to Mairie de Montrouge officially opened to passengers, marking the first extension of Line 4 since its inception.
* '''2016:''' Automation work begins.
* '''13 January 2022:''' Extension south to Bagneux-Lucie Aubrac officially opened to passengers.
* '''12 September 2022:''' First automatic trains (MP89, MP05 and MP14) enter service
* '''15 December 2023:''' Last day of driver operated services

===Origins===
[[File:Metro de Paris - Trace ligne 4 Ile de la Cite.jpg|thumb|upright|Original abandoned route (black) and built route (red) of Line 4 through the [[île de la Cité]].]]
Line 4, opened in 1908, was the last line of the original concession of the [[Compagnie du chemin de fer métropolitain de Paris]] and the first to cross the [[Seine]] underground ([[Paris Métro Line 5|Line 5]]—now [[Paris Métro Line 6|Line 6]] at this point—crossed the river on the Passy bridge, later renamed the [[Pont de Bir-Hakeim]] in 1906). The route was the subject of lengthy discussions that delayed the start of construction of the tunnel. It was originally planned as a straight line under the Rue du Louvre, under the Seine in line with the street, under the [[Institut de France]], along the Rue de Rennes and then the [[Boulevard Raspail]] to the Porte d'Orleans.

But as a result of the delay in beginning the extension of the Rue de Rennes as part of [[Haussmann's renovation of Paris|Haussmann's plan]] to the Seine—which was never carried out—and the outcry from the academicians who refused categorically to agree to the line passing under the Institut de France, the route was eventually changed to cross further east through the [[Place du Châtelet]] and the [[Île de la Cité]].<ref>Robert (1983), p. 71</ref> The new route also has more coherence as a north–south route following the main traffic flows. A second modification of the route was also made: it was decided to make a temporary deviation via the major station of [[Gare Montparnasse]] to avoid a further delay in opening the line, which was eagerly awaited. This was made necessary by the delay in building the new Boulevard Raspail between Rue de Rennes and Boulevard du Montparnasse.<ref>Tricoire (1999), p. 187</ref> Once the Boulevard Raspail was completed, it was planned to take the shorter route and bypass the Gare Montparnasse. To the south of the [[Vavin (Paris Métro)|Vavin]] station the tunnel provides for the final route along the Boulevard Raspail. But the value in serving three major mainline stations by the line later led to the abandonment of this proposal.<ref>Robert (1983), p. 74</ref>

===A spectacular construction site===
In 1905 construction was started by the company of [[Léon Chagnaud]]—a former mason from [[Creuse]] (a [[Departments of France|department]] with a tradition of supplying building workers in France)—and line 4 became the first to cross the Seine underground. The method used for crossing under the river is that of metal [[Caisson (engineering)|caissons]], twenty to forty meters in length mounted on the banks and sunken vertically in the river bed. The ends of the caissons were blocked and they were towed to their location before being ballasted with water and sunk in the riverbed. A chamber filled with pressurised air was built at the lower level of these caissons so that workers could excavate under the caissons. Each caisson gradually sank to its final position as the ground below it was removed. The northern stream of the [[Seine]] required three caissons, the southern stream two caissons.

The crossing of the Seine also involved the freezing of saturated ground between the station of [[Saint-Michel (Paris Métro)|Saint-Michel]] and the Seine, under the line of the [[Chemin de Fer de Paris à Orléans]] (now [[Réseau Express Régional|RER]] [[RER C|line C]]) in 1908 and 1909. The installation of two refrigeration plants allowed the movement of brine cooled to −25&nbsp;°C in dozens of tubes to stabilize the ground.<ref>{{Cite web|url=http://www.stif.info/les-transports-aujourd-hui/les-principaux-modes-transports/historique-transports/metro-33.html|title= Historique du métro (History of the metro)| publisher=[[Syndicat des transports d'Île-de-France]] | access-date= 18 September 2009}}</ref>

The northern section was the first completed: it was opened on 21 April 1908 from [[Porte de Clignancourt (Paris Métro)|Porte de Clignancourt]] to [[Châtelet (Paris Métro)|Châtelet]]. The southern section was opened 30 in October 1909 from [[Porte d'Orléans (Paris Métro)|Porte d'Orleans]] to [[Raspail (Paris Métro)|Raspail]]. The two sections were connected on 9 January 1910. However, the line was closed to traffic a few days later in January 1910, when the level of the Seine broke its banks during the [[1910 Great Flood of Paris|worst flood of the century]]. On the morning of 24 January 1910, a significant inflow of water at the Seine crossing interrupted services between Châtelet and Vavin, although services were restored later in the day. But the inflow increased and services were again halted in the afternoon. On 26 January Châtelet station and the crossing under the river was completely flooded and slowly rose in the tunnel. On the night of 27 and 28 January, flooding reached [[Réaumur - Sébastopol (Paris Métro)|Réaumur – Sébastopol]] and eventually [[Gare de l'Est (Paris Métro)|Gare de l'Est]]: The line at its minimum was reduced to operating between Clignancourt and Gare du Nord and between Vavin and Porte d'Orleans. The fall in the level of flooding during February allowed a gradual resumption of operations, but full service was not restored to 6 April after repair of extensive damage caused to the infrastructure.<ref>Robert (1983), pp. 74–78</ref>

During the politically turbulent 1930s, Line 4 had its own drama: on 27 July 1934, a package left in a carriage was carried into the office of its chief supervisor, located on the platform of Montparnasse. The package exploded, killing the chief supervisor and another officer and wounding four passengers. The assassins were never found.<ref>Robert (1983), p. 372</ref>

During World War II the most violent bombing Paris suffered was on the night of 20 and 21 April 1944 when the rail freight yard of la Chapelle and the main truck workshop at Rue Championnet were hit. The roof of the [[Simplon (Paris Métro)|Simplon]] station was hit by a bomb and it collapsed on the tracks and platforms. After repairs the line was brought back into service a few days later.<ref>Robert (1983), p. 140</ref>

<gallery widths="180">
File:Malcuit - Métropolitain de Paris - Souterrain construit sur caisson à air comprimé.JPG|Postcard explaining the construction of the crossing under the [[Seine]] by the use of pressurised sunken [[Caisson (engineering)|caissons]]
Image:Paris - Les travaux du Metropolitain - Foncage d un caisson.jpg|Sinking of a caisson in the narrow (southern) stream of the [[Seine]] in 1906
Image:Paris - Les travaux du Metropolitain - Foncage du caisson central.jpg|Sinking of the central caisson in the northern stream of the Seine
Image:Paris - Les travaux du Metropolitain place Saint-Michel.jpg|Sinking of the [[Saint-Michel (Paris Métro)|Saint-Michel]] station
Image:Paris - Travaux du Metropolitain - Les fermes de la place Saint-Michel.jpg|Work sites in the Place Saint-Michel and Boulevard Saint-Andre before the sinking
</gallery>

===The rubber tyre metro and the deviation of the line===
{{main| Rubber-tyred metro}}
[[File:Metro Paris rubber wheel.jpg|thumb|right|[[MP 59]] rubber-tyred trains.]]
The RATP was satisfied by experimentation with [[Rubber-tyred metro|rubber tyres]] on [[Paris Métro Line 11|Line 11]] beginning in 1956. It therefore decided to equip lines 1 and 4 for rubber-tyre operations, which can increase line capacity by providing better acceleration and decelerations as a result of a much superior grip.

In the early 1960s these two lines were the two busiest on the network, with loads of 140% of capacity during the evening peak. However, as this change alone was insufficient to overcome this saturation, the length of stations was lengthened from {{Convert|75 to 90|m|ftin}}, allowing the lengthening of train from five to six carriages. This work was carried out very quickly and, as early as October 1965, trains of six carriages traversed the line. On 3 October 1966, the first train composed of [[MP 59]] [[electric multiple unit]]s operated on the line. The Line 4 trains were identical to those on Line 1, being composed of four motors and two trailers per train. The line's MP 59 fleet included 556 carriages: 376 powered carriages and 180 trailers. On 17 July 1967, the last steel-wheeled train left the line to strengthen the service of others with a hundred cars built before 1914 scrapped.<ref>Robert (1983), pp. 157–158</ref> In February 1971, line 4 was the second network after line 11 to be equipped with semi-automatic operation, with a system known as ''Grecque'' ("Greek"). This allowed trains to run automatically once started by the driver and stop at the next station.<ref>Sirand-Pugnet (1997), p. 43</ref>

Since its opening the only change of the route of the line took place in early October 1977 with the deviation of the line with the relocation of the station at [[Les Halles (Paris Métro)|Les Halles]]. During the excavation of the enormous [[Les Halles]] complex the station of Les Halles was relocated about ten metres further east to allow a shorter connection to [[Châtelet – Les Halles (Paris RER)|Châtelet – Les Halles]] RER station. For this, three hundred and thirty meters of tunnel were built to join the old route. The changeover took place on three consecutive nights from 10&nbsp;PM on Friday, 30 September 1977 to the beginning of services on Monday, 3 October. On the first night, the new track 2 was connected, on the second night, the new track 1 was built and on the last night it was connected.<ref>Sirand-Pugnet (1997), pp. 119–22</ref>

On 6 August 2005 at 4:42&nbsp;pm, a fire on a train at Simplon due to the malfunction of a [[circuit breaker]] caused the evacuation of two MP 59 trains with 19 people mildly affected. The fire was extinguished by fire fighters at around 6:00&nbsp;pm.<ref>{{Cite web|url=http://www.bea-tt.equipement.gouv.fr/rubrique.php3?id_rubrique=58|title=L'incendie de deux rames de métro de la ligne 4 à la station Simplon le 6 août 2006|publisher=Bureau d'Enquêtes sur les Accidents de Transport Terrestre  |language=fr|access-date=18 September 2009}}</ref>

===Extension to Montrouge and the MP 89===
[[File:MP89 et MP59 se croisent à Odéon par cramos.jpg|thumb|Transition of rolling stock from the MP 59 to the MP 89 took place during 2011 and 2012.]]
Until 2013, Line 4 was one of a few lines (the others being semicircular lines 2 and 6, as well as the then new Line 14) that had never been extended beyond the "gates" of Paris. During the 1920s, a preliminary extension towards la Vache-Noire was planned but never carried out. Since that time, no other extension plan was brought up. In 2008, nearly a century after its opening, construction of a one-station extension towards {{stn|Mairie de Montrouge}} began. The new station officially opened to passengers on 23 March 2013, allowing one to travel from Montrouge to Clignancourt in 30 minutes.<ref>http://www.ratp.fr/fr/ratp/c_5097/actualites/ {{Webarchive|url=https://web.archive.org/web/20130302152017/http://www.ratp.fr/fr/ratp/c_5097/actualites/ |date=2 March 2013 }} La ligne 4 arrive à Montrouge - RATP - Retrieved 3/23/2013 (In French)</ref> Mairie de Montrouge is a traditional two-tracked station.

In addition to the Montrouge extension, in 2011 there has been a much needed refreshing in rolling stock for Line 4, as the MP 59 trainsets were reaching the end of their useful lives. The automation of Line 1 and purchasing of new automated rolling stock (the [[MP 05]]) allowed the RATP to replace the MP 59 with the [[MP 89]]CC rolling stock from [[Paris Métro Line 1|Line 1]]. Testing of the MP 89 during overnight hours took place in 2010, with the first train (#01) to be transferred to Line 4 in April, 2011 and enter service on 23 May 2011. A second train (#44) entered service on 10 September 2011. The first MP 59 train that was retired was #6049, which was pulled from service in April, 2011.

As the MP 05 rolling stock began to debut on Line 1, the pace of transferring the MP 89CC stock from Line 1 to Line 4 increased to roughly 3 trains per month. Since January 2012, the RATP kept this rate of transfer (increasing the rate to 4 trains during November and December) despite only being able to remove 2 MP 59 trainsets from service each month. During the course of 2011, the following trains were transferred from Line 1 to Line 4: #s 14, 20, 29, 30, 31, 34, 38, and 40. Train #s 03 through 25, 27 through 42, 43, 44, 48, 49, 51, and 52 were transferred during the course of 2012. #45 was transferred on 3 January 2013, marking the 47th train to be moved to Line 4. Between February and March 2013, #s 02, 46, 47, and 50 were transferred. The final MP 89CC train was #26. The last MP 59 train to be pulled from service was #6021, which was withdrawn on 21 December 2012. Though many MP 59 trains operated on Line 4 for roughly 45 years, those trains that were brought over from Line 1 during the late 1990s have circulated throughout the Metro for about 50 years.{{Citation needed|date=March 2020}}

===Extension to Bagneux===
[[File:Station Mairie Montrouge Métro Paris Ligne 4 - Montrouge (FR92) - 2022-07-05 - 1.jpg|thumb|Mairie de Montrouge]]
Following the opening of Mairie de Montrouge, plans were already in the works to further extend Line 4 another 1.8km southward. This extension consists of two stations: {{stn|Barbara}} at the border between Montrouge and Bagneux (in Montrouge) and {{stn|Bagneux–Lucie Aubrac}}. In October 2011, the STIF announced that construction of the Bagneux extension began in 2014.<ref>{{cite news |title=M4 extension to Bagneux |url=https://www.ratp.fr/en/groupe-ratp/metrotrains/m4-extension-bagneux#:~:text=The%20highly%2Dawaited%20extension%20south,up%20service%20by%20mid%2D2021. |work= Live from the RATP Group |date=2018-04-18 |access-date=2021-05-21}}</ref> The extension opened on 13 January 2022.<ref name=":0" /> In 2025, Bagneux-Lucie Aubrac will provide a connection to [[Paris Métro Line 15]] of [[Grand Paris Express]].<ref>{{Cite web|date=2017-05-02|title=Ligne 15 Sud|url=https://www.societedugrandparis.fr/gpe/ligne/ligne-15-sud|access-date=2022-01-13|website=Société du Grand Paris|language=fr}}</ref>

=== Automation of the line ===
Like [[Paris Métro Line 1|Line 1]], the line has been converted to an automated system.<ref>{{cite web |url=http://www.railwaygazette.com/news/single-view/view/ratp-cleared-to-automate-paris-metro-line-4.html |url-status=dead |archive-url=https://web.archive.org/web/20130715061504/http://www.railwaygazette.com/news/single-view/view/ratp-cleared-to-automate-paris-metro-line-4.html |archive-date=15 July 2013 |title=RATP cleared to automate Paris metro Line 4 - Railway Gazette}}</ref> The beginning of the conversion was initially planned shortly after the completion of the [[Paris Métro Line 1|Line 1]], but was put on hold for a time due to high costs ''(From [[:fr:Ligne 4 du métro de Paris]])''. The RATP confirmed on 2 April 2013 that Line 4 would be fully automated, but still stopped short of giving a timeline of the conversion.<ref>http://www.lefigaro.fr/societes/2013/04/02/20005-20130402ARTFIG00282-la-ratp-prepare-l-automatisation-de-la-ligne-4-du-metro-parisien.php La RATP prépare l'automatisation de la ligne 4 du métro parisien {In French} - Retrieved 3 April 2013</ref> In January 2016, [[Siemens]] was awarded a €70 million contract to fully automate Line 4.<ref name="Automation1">{{cite news|url=http://www.siemens.com/pres/en/pressrelease/?press=/en/pressrelease/2016/mobility/pr2016010120moen.htm&content[]=MO|title=Siemens to equip Line 4 of the Metro Paris for driverless operation|publisher=Siemens.com|date=2016-01-07|access-date=2017-05-07}}</ref> The plan at that time was that a mix of crewed and driverless trains would start running in 2020 and that the line would be fully driverless by 2022.<ref name="Automation1" />

Delays partly brought upon by the [[COVID-19]] pandemic however pushed the introduction of mixed rolling stock back to summer 2022. This involved transferring MP 89CA and MP05 railcars from [[Paris Métro Line 14|Line 14]], which are in-turn replaced there by the first batch of [[MP 14 (Paris Métro)|MP 14CA]] sets. The MP 89CC trains removed from line 4 are themselves refurbished, shortened to 5 cars, and transferred to [[Paris Métro Line 6|Line 6]]. The first MP 89CA and MP 05 railcars entered Line 4 revenue service on 12 September 2022, and were followed by the first MP 14CA trainset on 15 September.{{fact|date=October 2024}}

Driver operated services ended on 15 December 2023. Since 16 December 2023, Line 4 is fully operated with driverless trains. <ref> {{cite web |url=https://www.ratp.fr/decouvrir/coulisses/modernisation-du-reseau/ca-bouge-sur-la-ligne-4[]=MO|title=Ça bouge sur la ligne 4|publisher=RATP.fr|date=2023-12-15|access-date=2023-12-18}}</ref>

==Future==

===Northern Extension towards Saint-Ouen===
Phase 1 (2007–2013) of the ''Schéma directeur de la région Île-de-France'' ("Master Plan for the [[Île-de-France (region)|Île-de-France]] region", ''SDRIF''), adopted by resolution of the Regional Council of Ile-de-France on 25 September 2008A, included a Northward extension to the "docks" of [[Saint-Ouen, Seine-Saint-Denis|Saint-Ouen]] (an urban redevelopment project next to the [[Seine]]) via [[Mairie de Saint-Ouen (Paris Métro)|Mairie de Saint-Ouen]] (where Line 4 would connect to Line 13's St. Denis branch and to Line 14).<ref>{{Cite web| publisher=Master Plan for the Île-de-France region| title=Développer le réseau pour accompagner le projet urbain (Expand the network to support urban development)| url=http://www.sdrif.com/fileadmin/unloud_file/doc_accueil/SDRIF.PDF|access-date=10 September 2009 |language=fr |page=81}}</ref> However no detailed studies have yet been carried out, nor any funding set aside.

==Rolling Stock==
Over the years, Line 4 has seen the following rolling stock.
* [[Sprague-Thomson]]: 1908 – 1967
* [[MP 59]]: 1966 – December 2012
* MP 89CC: May 2011 – December 2023
* [[MP 89]]CA: September 2022 – present
* [[MP 05]]: September 2022 – present
* [[MP 14 (Paris Métro)|MP 14]]CA: September 2022 – present

''(From [[:fr:Ligne 4 du métro de Paris]])''

==Workshops==
Until March 2013; light maintenance of the MP 89CC rolling stock of Line 4 was handled within the station of Porte d'Orléans (CDT). Platform 2 of the station (in the direction of Porte de Clignancourt contains inspection pits, which allow routine light maintenance work and troubleshooting of the first level. Both Porte d'Orléans and Porte de Clignancourt also contain loop tracks where trains can be stored overnight (although many trains are stored within the main tunnels due to a lack of a sufficient garage). This protocol changed when a new garage located south of the new station Mairie de Montrouge opened. Track 3 of station Porte d'Orléans will eventually be dismantled and covered over to make way for a new access point into the station.

Second level maintenance is handled at the Saint-Ouen shops, located just to the north of the Porte de Clignancourt terminus (and its northern loops). The facility extends over an area of 34,000 sq meters and opened in 1908. The shops have been renovated and expanded over the years, including a recent extension to house MP 89CC trainsets that are undergoing routine maintenance (AMT).

In addition to maintaining the MP 89CC trainsets, the Saint-Quen shops also handle heavy maintenance and overhaul of the MF 77 steel-wheel stock trains for lines 7, 8 and 13, as well as numerous auxiliary/service trains. The shop is also specialized in the review of electronic equipment of all network hardware. As of 2007, 60 officers are assigned to train maintenance and 220 to the maintenance of equipment.

All heavy maintenance work for the MP 89CC trainsets are handled in the workshops of Fontenay, located just east of the Chateau de Vincennes terminus of Line 1.

''(From [[:fr:Ligne 4 du métro de Paris]])''

==Map and stations==
[[File:Carte Métro Paris Ligne 4 (2022-01).svg|thumb|Geographical map of Paris Métro Line 4]]

===Stations renamed===
* '''15 November 1913:''' Vaugirard station was renamed Saint-Placide.
* '''5 May 1931:''' Boulevard Saint-Denis was renamed Strasbourg – Saint-Denis.
* '''25 August 1931:''' Marcadet (on line 4) and Poissonniers (on line 12) were combined and the resulting station was renamed Marcadet – Poissonniers.
* '''6 October 1942:''' Montparnasse (on lines 4 and 12) and Bienvenüe (on lines 6 and the current 13) were combined and the resulting station was renamed Montparnasse – Bienvenüe.
{{clear|left}}

[[File:Plan Linéaire Métro Paris Ligne 4 - 2022-01-13.svg|thumb|750px|left|Map of Paris Métro Line 4.]]
{{clear|left}}

===Themed Stations===
* [[Réaumur – Sébastopol (Paris Métro)|Réaumur – Sébastopol]] has an interactive exhibition devoted to the [[Conservatoire National des Arts et Metiers]] (CNAM), located nearby. There are also LCD screens that include interviews and short films on the teaching of the conservatory.
* [[Barbès – Rochechouart (Paris Métro)|Barbès – Rochechouart]] has an exhibit on the occupation of Paris during World War II, including newspaper clippings, photos, and a map showing the insurrection of Paris in August 1944
* [[Odéon (Paris Métro)|Odéon]] has a small exhibit on the northbound platform that is dedicated to [[Georges Jacques Danton]]; it includes a bust of the French revolutionary, and a copy of the decree proclaiming the First Republic in 1792 .
* [[Saint-Germain-des-Prés (Paris Métro)|Saint-Germain-des-Prés]] is lined with decor evoking the history of literary creation in the district. Extracts of literary works are projected onto the roof, the station being devoid of the usual billboards. This exhibit showcases the stories of young talent in literature.
* [[Montparnasse – Bienvenüe (Paris Métro)|Montparnasse – Bienvenüe]] contains an exhibit honoring principal [[engineer]] of the Paris Métro, [[Fulgence Bienvenüe]]. It has been naturally selected as an exhibition space on the network technology and literary history of the subway in 2000 during its centennial. Many books citing excerpts from the subway especially adorn the grand hall that connects each of the four metro lines in the station (4, 6, 12, and 13).
* [[Mouton-Duvernet (Paris Métro)|Mouton-Duvernet]] was once adorned with orange wall tiles when it was renovated in 1970. The orange styling quickly became known as the "Mouton style". However, the station was renovated again during the 2000s, reverting its theme back to the classic white tile.
* Both [[Saint-Michel (Paris Métro)|Saint-Michel]] and [[Cité (Paris Métro)|Cité]] contain dark-colored metal structures that serve as interconnecting levels between the platform level and the entry/ticketing level.
''(From [[:fr:Ligne 4 du métro de Paris]])''

==Tourism==
Metro line 4 passes near several places of interest and therefore often crowded :
* Barbès and the Goutte d'Or and their African and Asian influences.
* [[Gare du Nord]] and [[Gare de l'Est]] 19th century train stations.
* L'[[Île de la Cité]] with the [[Notre-Dame de Paris|Notre-Dame Cathedral]].
* Saint-Michel and the [[Latin Quarter]].
* Saint-Germain des Prés quarter with its church and famous cafés.
* Rue de Rennes shopping street.
* [[Luxembourg Garden]].
* [[Montparnasse]], its famous cafés, the [[Gare Montparnasse]] and the [[Tour Montparnasse|Montparnasse Tower]].

== Reception ==
According to [[Facebook]] [[List of Facebook features#Groups|group]] [[New Urbanist Memes for Transit-Oriented Teens]], M4 is considered "[[Alignment (Dungeons & Dragons)#Chaotic good|chaotic good]]" on the ''[[Dungeons & Dragons]]'' (''D&D'') [[Alignment (Dungeons & Dragons)|alignment system]].<ref name="Mortice 2018-1">{{cite web|last=Mortice|first=Zach|title=Meet the 61,000 Transit Nerds of Facebook's 'New Urbanist Memes for Transit-Oriented Teens'|url=http://www.chicagomag.com/city-life/March-2018/Meet-the-61000-Transit-Nerds-of-Facebooks-New-Urbanist-Memes-for-Transit-Oriented-Teens/|work=[[Chicago (magazine)|Chicago]]|publisher=[[Tronc]]|date=29 March 2018|access-date=30 April 2018}}</ref><ref name="Mortice 2018-2">{{cite web|last=Mortice|first=Zach|title=Meet the 61,000 Transit Nerds of Facebook's 'New Urbanist Memes for Transit-Oriented Teens'|url=http://zachmortice.com/2018/04/09/meet-61000-transit-nerds-facebooks-new-urbanist-memes-transit-oriented-teens/|work=Zach Mortice|publisher=zachmortice.com|date=9 April 2018|access-date=30 April 2018}}</ref>

==Gallery==
<gallery mode="packed">
Image:Station Cité Métro Paris Ligne 4 - Paris IV (FR75) - 2022-07-02 - 1.jpg|[[Cité (Paris Métro)|Cité]]
File:Station Mairie Montrouge Métro Paris Ligne 4 - Montrouge (FR92) - 2022-07-05 - 1.jpg|Mairie de Montrouge
Image:Station Marcadet Poissonniers Métro Paris Ligne 4 - Paris XVIII (FR75) - 2022-07-05 - 4.jpg|[[Marcadet - Poissonniers (Paris Métro)|Marcadet – Poissonniers]]
File:Station Mouton Duvernet Métro Paris Ligne 4 - Paris XIV (FR75) - 2022-07-05 - 1.jpg|[[Mouton-Duvernet (Paris Métro)|Mouton-Duvernet]]
Image:Station Montparnasse Bienvenüe Métro Paris Ligne 4 - Paris VI (FR75) - 2022-07-02 - 3.jpg|[[Montparnasse - Bienvenüe (Paris Métro)|Montparnasse – Bienvenüe]]
Image:Station Odéon Métro Paris Ligne 4 - Paris VI (FR75) - 2022-07-02 - 5.jpg|[[Odéon (Paris Métro)|Odéon]]
Image:Station Porte Orléans Métro Paris Ligne 4 - Paris XIV (FR75) - 2022-07-05 - 7.jpg|[[Porte d'Orléans (Paris Métro)|Porte d'Orleans]]
Image:Station Saint Germain Prés Métro Paris Ligne 4 - Paris VI (FR75) - 2022-07-02 - 2.jpg|[[Saint-Germain-des-Prés (Paris Métro)|Saint-Germain-des-Prés]]
Image:Station Vavin Métro Paris Ligne 4 - Paris VI (FR75) - 2022-07-04 - 1.jpg|[[Vavin (Paris Métro)|Vavin]]
Image:MP 59.ogg|Vavin
</gallery>

==References==
{{reflist}}

*{{Cite book|first=Jean|last= Robert|title= Notre métro ("Our metro")|language=fr|year=1983 }}
* {{Cite book|first=Jean|last= Tricoire|title= Un siècle de métro en 14 lignes. De Bienvenüe à Météor ("A century in 14 metro lines. From Bienvenüe to Météor"|language=fr| publisher=La Vie du rail |year=1999 |isbn=978-2-902808-87-8 }}
* {{Cite book|first=Bernard |last= Sirand-Pugnet|title=De la Grand-mère à Météor, 45 ans d'évolution de la technologie des voies au métro de Paris ("From the Grandmother to the Météor, 45 years of evolution of the technology of the lines of the Paris métro"|language=fr|year=1997 |isbn=978-2-912252-00-5  }}

==See also==
{{columns-list|colwidth=22em|
* [[Paris]]
* [[Transport in Paris]]
* [[List of stations of the Paris Métro]]
* [[List of stations of the Paris RER]]
* [[List of metro systems]]
* [[Rail transport in France]]
}}
{{Clear}}
{{Portal bar|France|Trains|Transport|Engineering}}
*

==External links==
{{commons category|Paris Métro Line 4}}
{{Wikivoyage|Paris}}
* {{in lang|fr}} [https://web.archive.org/web/20081225184032/http://www.ratp.fr/ RATP official website]
* {{in lang|en}} [https://web.archive.org/web/20101216073740/http://www.ratp.info/informer/anglais/index.php RATP english speaking website]
* {{in lang|en}} [https://web.archive.org/web/20091218101446/http://www.ratp.info/orienter/cv/carterer.php Interactive Map of the RER (from RATP's website)]
* {{in lang|en}} [https://web.archive.org/web/20090704015810/http://www.ratp.info/orienter/cv/carteparis.php Interactive Map of the Paris métro (from RATP's website)]
* {{in lang|fr}} [http://membres.lycos.fr/mobidf/ Mobidf website, dedicated to the RER (unofficial)]{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}
* {{in lang|fr}} [https://web.archive.org/web/20051208073801/http://www.metro-pole.net/ Metro-Pole website, dedicated to Paris public transports (unofficial)]
* [http://www.infovisual.info/05/050_en.html TRUCK (bogie)]

{{Paris Transport Network}}
{{Paris Metro/line 4}}

{{DEFAULTSORT:Paris Metro Line 4}}
[[Category:1908 establishments in France]]
[[Category:Articles containing video clips]]
[[Category:Paris Métro line 4| ]]
[[Category:People mover systems in France]]
[[Category:Railway lines opened in 1908]]