RER A

RER A
standard gauge
Electrification	Overhead line:     25 kV 50 Hz AC     1,500 V DC
Route map Show geographically accurate map Legend  A3  Cergy-le-Haut   Cergy–Saint-Christophe   Cergy–Préfecture   l'Oise Neuville–Université   Conflans-Fin-d'Oise      Poissy  A5  l'Oise Achères–Grand-Cormier Achères-Ville     Saint-Germain-en-Laye  A1  Maisons-Laffitte   la Seine Le Vésinet–Le Pecq Sartrouville   Le Vésinet–Centre Chatou–Croissy Carrières-sur-Seine    la Seine Rueil-Malmaison Nanterre-Ville ↑ 1.5 kV DC Nanterre–Université Nanterre-Préfecture  *        La Défense la Seine     Charles de Gaulle–Étoile        Auber          Châtelet–Les Halles        Gare de Lyon      Nation Vincennes Fontenay-sous-Bois Val de Fontenay   Nogent-sur-Marne Neuilly-Plaisance Joinville-le-Pont la Marne Tvm  * Saint-Maur–Créteil Bry-sur-Marne Le Parc de Saint-Maur Noisy-le-Grand – Mont d'Est Champigny Noisy–Champs   * La Varenne–Chennevières Noisiel la Marne Lognes Sucy–Bonneuil Torcy Boissy-Saint-Léger  A2  Bussy-Saint-Georges Val d'Europe  A4  Marne-la-Vallée–Chessy all stations are accessible, except Achères–Grand-Cormier (*) Under construction This diagram: view talk edit Show diagram map

RER A is one of the five lines in the Réseau Express Régional (English: Regional Express Network), a hybrid commuter rail and rapid transit system serving Paris, France and its suburbs. The 108.5-kilometre (67.4 mi) line crosses the region from east to west, with all trains serving a group of stations in central Paris, before branching out towards the ends of the line.

The initial portion of the line was built in stages between December 1969 and December 1977 by connecting two existing suburban commuter rail lines with a new tunnel under Paris: the line between

Since opening, three additional branches have been added: one in the east serving Marne-la-Vallée and Disneyland Paris and two to the west serving Poissy and Cergy.

The RER A has had a significant social impact on Paris and the surrounding region by speeding up trips across central Paris, by making far fewer stops than the Paris Métro and by bringing far-flung suburbs within easy reach of the city centre. The line has far exceeded all traffic expectations, currently serving over 1.2 million passengers per day, on about 300 million journeys per year. It is one of the busiest metro lines in Europe.

Popular success and responses

The line has far exceeded all traffic expectations, currently serving over 1.2 million passengers per day, on about 300 million journeys per year.^[2][3] It has been argued that this makes the RER A the busiest single rail line outside of East Asia.^[4] Ever-increasing traffic volume and the need to ward off imminent saturation have been major factors in RATP and SNCF's planning since the inauguration of the line.

Several major capital investments have been made to relieve overcrowding on the line:

• The line's traditional
  Système d'aide à la conduite, à l'exploitation et à la maintenance or SACEM (English: Driver Assistance, Operation, and Maintenance System) enables extremely short spacing between trains, increasing capacity on the line. The SACEM system is scheduled to be replaced in the mid- to late-2020s with an even more advanced communications-based train control
  system.
• Paris Métro Line 14, which opened 15 October 1998, was built on a route that would relieve congestion on the segment of RER A that passes through central Paris.
• RER E, which opened 14 July 1999, was built on a route that would also serve the eastern suburbs of Paris and an 8 km (5.0 mi) tunnel is being built under central Paris that will connect the RER E to La Défense. Once the tunnel is complete, the RER A's A5 branch to Poissy will be served by the RER E. The project is expected to reduce the load on the central section of the RER A by 10-15%
• Double-deck trains (MI 2N series) entered service in 1998 to increase the passenger carrying capacity on each run of the RER A. The 43 double-deck trains can carry up to 2,600 people per train, compared to 1,887 people on the older single-deck MS 61 trains. The double-deck trains proved so successful and popular, that RATP placed an order for 140 MI 09 double-deck trains that entered service in 2011, and has replaced all the remaining single-deck trains on the RER A.^[5]

Chronology

SACEM

.

• 6 July 1961: First planning begins for tunnel under Paris to connect Étoile to the new La Défense business district. These plans would go on to become the much more ambitious RER A.
• 14 December 1969: The first Regional Metro segment begins service after RATP purchases the Ligne de Vincennes between
  Nation
  , which replaces Bastille as the terminus. This creates a 17.5 km (10.9 mi) eastern line between Nation and Boissy-Saint-Léger.
• 19 January 1970: 4 km (2.5 mi) tunnel opens between Étoile and La Défense. Since this tunnel is isolated from the other section, it is operated as a navette (shuttle) service.
• 23 November 1971: Tunnel extended 2 km (1.2 mi) east to Auber. Shuttle service extended to operate between
  Auber
  .
• 1 October 1972: The second Regional Metro segment opens as RATP purchases the Ligne de Saint-Germain between Nanterre-Université and Saint-Germain-en-Laye from SNCF and connects it to a new 2 km (1.2 mi) tunnel to La Défense. This creates a 13 km (8.1 mi) western line between Saint-Germain-en-Laye and Auber.
• 1 October 1973: New
  Nanterre–Préfecture station
  opens.
• 8 December 1977: The Regional Metro becomes RER A as the final 6 km (3.7 mi) segment under Paris is completed, adding two new underground stations:
  Noisy-le-Grand-Mont d’Est
  .
• 19 December 1980: The Ligne nouvelle de Marne-la-Vallée extended 9 km (5.6 mi) to
  Torcy
  .
• 29 May 1988: "Interconnexion Ouest" (English: West Interconnection) branch added, extending trains 15.5 km (9.6 mi) northwest on SNCF tracks from
  Cergy-Saint-Christophe
  .
• 29 May 1989: 8.5 km (5.3 mi) branch added off the "Interconnexion Ouest" connecting Maisons-Laffitte and Poissy.
• 1 April 1992: The Ligne nouvelle de Marne-la-Vallée completed with 11 km (6.8 mi) extension to Marne-la-Vallée–Chessy, creating a link to Disneyland Paris, which would open on 12 April 1992.
• 29 August 1994: Line extended 2.5 km (1.6 mi) west to Cergy-le-Haut, new
  Neuville-Université
  station opens.
• 10 June 2001: New Val d'Europe station opens.

List of RER A stations

• A1
  • Saint-Germain-en-Laye
  • Le Vésinet – Le Pecq
  • Le Vésinet – Centre
  • Chatou – Croissy
  • Rueil-Malmaison
  • Nanterre – Ville
  • Nanterre – Université
• A3, A5
  • A3
    • Cergy-le-Haut
    • Cergy-Saint-Christophe
    • Cergy-Préfecture
    • Neuville-Université
    • Conflans-Fin-d'Oise
    • Achères-Ville
  • A5
    • Poissy
    • Achères – Grand Cormier
  • Maisons-Laffitte
  • Sartrouville
  • Houilles–Carrières-sur-Seine
• Nanterre-Préfecture
• La Défense
• Charles de Gaulle–Étoile
• Gare d'Auber
• Châtelet–Les Halles
• Gare de Lyon
• Nation
• Vincennes
• A2
  • Fontenay-sous-Bois
  • Nogent-sur-Marne
  • Joinville-le-Pont
  • Saint-Maur – Créteil
  • Le Parc de Saint-Maur
  • Champigny
  • La Varenne – Chennevières
  • Sucy – Bonneuil
  • Boissy-Saint-Léger
• A4
  • Val de Fontenay
  • Neuilly-Plaisance
  • Bry-sur-Marne
  • Noisy-le-Grand – Mont d'Est
  • Noisy – Champs
  • Noisiel
  • Lognes
  • Torcy
  • Bussy-Saint-Georges
  • Val d'Europe
  • Marne-la-Vallée – Chessy

Operation

Branches

Line A provides two groups of services:

• St Germain branch – common trunk line – Boissy branch
• Cergy or Poissy branches – common trunk line – Marne la Vallée branch.

During off-peak hours, the Poissy – Noisy services operate every 20 minutes plus a La Défense – Noisy service every 20 minutes, and the St-Germain – Boissy and Cergy – Chessy services operate every 10 minutes.

Operations are very complex during

, with an average of one train every 2 minutes (30 trains / hour) on the common trunk line in the busier direction (east to west in the morning, west to east in the evening), and one train every 2 min 30 sec in the other direction (24 trains / hour). The Marne la Vallée branch has the most intensive service.

Names of services

This section needs to be updated. Please help update this article to reflect recent events or newly available information. (March 2022)

RER trains display a "nom de mission" or "name of service", not the name of the destination station. These are invented names designating (and distinguishing) individual services ("runs"), and are accompanied by a two-digit number, for example ZARA59 or DJIB72.

The first letter corresponds to the destination (gare d'arrivée):

Letter	To	Examples of names of services
B	La Défense	BYLL, BORA, BTON
D	Noisy-le-Grand – Mont d'Est	DYNO, DJIN, DOMI
N	Boissy-St-Léger	NELY, NAGA
O	Torcy	OKEY, ORKA, OFRE
Q	Marne-la-Vallée – Chessy	QUDO, QIKY, QBIK, QAHA
R	La Varenne-Chennevières	RHIN, RUDI
T	Poissy	TERI, TJAC, TIKY
U	Cergy-le-Haut	UPAL, UDON, UXOL
W	(empty train)	WQWZ
X	Le Vésinet – Le Pecq	XUTI, XOUD
Y	Rueil-Malmaison	YCAR, YVAN
Z	Saint-Germain-en-Laye	ZARA, ZEUS, ZINC

The second letter corresponds to the stations served and the origin station: a letter can have different meanings, depending on the destination. For instance, second letter "E" indicates:

• with first letter "N" or "Z", all stations
  Boissy-St-Léger
  (NELY or ZEUS);
• with first letter "Q",
  Bry-sur-Marne
  (QENO).

The third and fourth letters are used to form a pronounceable name, changed when the service number (odd 01–99 eastward, even 02–98 westward) reaches the maximum. For example, successive trains to

are called NEGE96, NEGE98, then NELY02, NELY04, etc. Each service is uniquely identifiable, as there cannot be two "NEGE" services with the same number in the same day.

Services with the same first two letters serve the same stations, e.g. ZEBU, ZEUS and ZEMA (to

). The letters ZZ generally indicate that the established service pattern was changed for an unspecified reason, generally a technical problem which disrupted operations.

Morning Peak

Every 10 minutes:

• Boissy – Le Vésinet-Le Pecq, all stations except Nanterre-Ville.
• La Varenne – St-Germain, all stations except Chatou-Croissy and Le Vésinet-Centre.
• Marne-la-Vallée – Chessy – Cergy-le-Haut, all stations except Lognes, Noisiel, Bry-sur-Marne, Houilles and Maisons-Laffitte.
• Marne-la-Vallée – Chessy – Poissy, all stations except Val d'Europe, Bussy-St-Georges, Lognes, Noisy-Champs and Sartrouville.
• Torcy – Rueil-Malmaison, all stations except Bry, Neuilly-Plaisance and Nanterre-Préfecture.
• Cergy – Torcy, all stations except Maisons-Laffitte, Houilles, Noisiel and Lognes.
• Poissy – Chessy, all stations except Neuilly-Plaisance and Bry.
• St-Germain – Boissy, all stations except Le Vésinet-Centre and Chatou-Croissy.
• Le Vésinet-Le Pecq – La Varenne, all stations except Nanterre-Préfecture, Vincennes and Fontenay.

Evening Peak

Every 10 minutes:

• Cergy – Noisy-le-Grand, all stations except Maisons-Laffitte and Houilles.
• Poissy – Chessy, all stations except Sartrouville, Bry, Noisiel and Lognes.
• St-Germain – Boissy, all stations except Nanterre-Ville and Nanterre-Préfecture.
• Le Vésinet-Le Pecq – La Varenne, all stations except Vésinet-Centre and Chatou-Croissy.
• La Défense – Torcy, all stations except Neuilly-Plaisance and Bry.
• Chessy – Poissy, all stations except Bry and Neuilly-Plaisance.
• Boissy – Le Vésinet-Le Pecq, all stations.
• Noisy – Cergy-le-Haut, all stations except Houilles and Maisons-Laffitte.
• La Varenne – St-Germain, all stations except Fontenay, Vincennes, Nanterre-Préfecture, Chatou-Croissy and Le Vésinet-Centre.

Off Peak

In both directions every 10 minutes:

• St-Germain-en-Laye – Boissy-St-Léger.
• Cergy-le-Haut – Marne la Vallée-Chessy.

In both directions every 20 minutes:

• Poissy – Noisy-le-Grand – Mont d'Est.
• La Défense – Noisy-le-Grand – Mont d'Est.

Off-peak, a train is scheduled every 3 minutes 20 seconds between La Défense and Vincennes in both directions.

See also

• List of stations of the Paris Métro
• List of stations of the Paris RER

References

External links

• Media related to RER A at Wikimedia Commons