RER A

Infobox Paris Network
Line=RER A
ColourName=#fe370f
TextColour=White
YearOpened=1977
LastExtension=1994
RollingStock=MS 61, MI 84, MI 2N
StationsServed=46
LengthKm=108.5
AverageInterstation=2,411
LengthMiles=67.4
AnnualPassengers=272,800,000

The RER A is one of the five lines in the RER Rapid transit system serving Paris, France.

The line runs from "Saint-Germain-en-Laye (A1), Cergy Le Haut (A3), and Poissy (A5). To Boissy-Saint-Léger (A2) and Marne-la-Vallée - Chessy (A4)"

* First inauguration: December 12, 1969
* Length: 108.5 km (67.4 miles)
* Number of stops: 46
* Traffic (2004): 272,800,000 journeys per annum "(figure only for the RATP section of the line)"

Line A is Europe's busiest line with over 1,000,000 passenger/day. Line A is formed from the connection across Paris of the Saint-Germain-en-Laye-Nanterre line in the west to the Vincennes — Boissy-St-Léger line in the east. Two branches were added in the West, to Poissy and the 'ville nouvelle' of Cergy, and another in the East, to the ville nouvelle of Marne-la-Vallée. The two latest extensions of the line were to Cergy-Le Haut and Disneyland Resort Paris.

Popular success and responses

Line A has been a runaway success since its inauguration and, with its million-plus passengers per workday, has frequently been presented as the busiest urban transit line in the world. This claim has been disputed (Gerondeau C, 2003 — see reference) by reference to the figure of 103,080 passengers per hour claimed by the Japanese Ministry of Transport for the JR Chūō Line in Tokyo — almost twice the equivalent figure (55,000) for the RER Line A (both 1992). Japan being something of a case apart in the field of rail transport, accounting for 40% of all train journeys in the world, it clearly remains the case that the RER Line A is an exceptionally busy route.

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 A. At least five major capital investment decisions can be directly traced back to this issue:

* In the early 1980s RATP contracted German conglomerate Siemens to develop a dynamic traffic control system that would remove the capacity constraints caused by conventional block traffic management. This system, called SACEM ("Système d'aide à la conduite, à l'exploitation et à la maintenance"), remains today one of the world's most advanced traffic control systems and enables extremely short spacing (under 90 seconds in stations, under 2 minutes in tunnels) between trains during rush hour. (Parisians have become used to the sight of a train pulling into a station as the one before it is just clearing the platform.)

* Around the same time, RATP had to order a significant number of additional MI79/MI84 trains to remedy premature wear and tear on its existing MS61 rolling stock caused by over-utilization of Line A.

* Later in the 1980s, the need to relieve congestion on the central segment of Line A was a key factor in selecting the route of the new, fully automated Line 14 (also known as METEOR) of the Métro.

* The same need governed the choice of the route of RER Line E in the early 1990s and is a factor in current plans for that line's westward or south-westward extension.

* An entirely new class of double-decker trains (MI 2N series) entered service in 1998, in part a product of RATP's belief that no further infrastructure improvement (short of an extremely expensive track quadrupling) would relieve congestion on Line A.

One simple (if partial) solution to the congestion problem that has never been implemented is a change in the seating configuration inside the trains themselves. The RER is unusual among high-capacity urban train networks in its attachment to "transversal" (front and back facing) seating. A change to "longitudinal" (sideways window-lining) seating typically reduces the number of seats by 10% but increases standing room by 30%. The result is increased capacity and a less cramped ride for those without seats.

Chronology

* December 14 1969: The Paris subway operator, the RATP, buys the "ligne de Vincennes" from the SNCF which connected Bastille with Boissy-Saint-Léger in the east. A new 2.5-km tunnel is built between Vincennes and Nation, which replaces Bastille as the terminus. Total length of segment: 17.5 km.
* February 21 1970: The RATP buys the "ligne de St-Germain" from the SNCF which connected St-Lazare train station with Saint-Germain-en-Laye in the west. A new tunnel is opened between La Défense and the Place de l'Étoile, which replaces St-Lazare as the terminus. Shuttle ("navette") service is operated La Défense - Étoile, 4 km.
* November 23 1971: Tunnel opened Étoile - Auber, 2 km. Shuttle service extended to operate La Défense - Auber.
* October 1 1972: Tunnel opened La Défense - Nanterre-Université, 2 km. Shuttle service extended on the "ligne de St-Germain" (La Défense - Saint-Germain-en-Laye, 13 km) to operate Saint-Germain - Auber.
* October 1973: New underground station, Nanterre-Préfecture, opened between La Défense and Nanterre-Université.
* December 9 1977: Both lines are connected with a new 6-km tunnel giving birth to the RER A line, Saint-Germain - Boissy-Saint-Léger, 42.5 km total. Two new stations were inaugurated: Châtelet-les Halles and Gare de Lyon. A new branch, "ligne nouvelle de Marne-la-Vallée," 8.5 km, was opened in the east from Vincennes to Noisy-le-Grand.
* December 19 1980: The "ligne nouvelle de Marne-la-Vallée" was extended from Noisy-le-Grand to Torcy, 9 km.
* May 29 1988: New service, "Interconnexion Ouest," Cergy-St-Christophe - Marne-la-Vallée (Torcy), 47 km total. Included new branch in the west from Nanterre-Université to Cergy-St-Christophe, 15.5 km.
* May 1990: Another branch was created in the west from Maisons-Laffitte to Poissy, 8.5 km.
* April 1 1992: The Marne-la-Vallée line was extended from Torcy to Marne-la-Vallée-Chessy, 11 km, in order to create a direct link from the centre of Paris to Disneyland Paris.
* August 29 1994: Extension opened Cergy-St-Christophe — Cergy-Le Haut, 2.5 km. New station, Neuville-Université, opened. Located between Conflans-Fin-d'Oise and Cergy-Préfecture.
* June 10 2001: New station, Val-d'Europe, opened. Located between Bussy-St-Georges and Marne-la-Vallée-Chessy.

Map

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
* 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 Cergy-Torcy and Poissy-Chessy services operate every 20 minutes, and the St-Germain - Boissy-St-Leger service operates every 10 minutes.

Operations are very complex during peak periods, with an average of one train every 2 minutes 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. The Marne la Vallée branch has the most intensive service.

Names of Services

RER trains do not display the name of the destination station, but instead display a "nom de mission" or "name of service." These are, literally, names used to designate (and distinguish) individual services ("runs"), and are accompanied by a two-digit number.

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

*B = La Défense
*D = Noisy-le-Grand Mont d'Est
*N = Boissy-St-Léger
*O = Torcy
*Q = Marne-la-Vallée - Chessy
*R = La Varenne-Chennevières
*T = Poissy
*U = Cergy - Le Haut
*W = No Passengers (Train vide, "Empty Train")
*X = Le Vésinet - Le Pecq
*Y = Rueil-Malmaison
*Z = Saint-Germain-en-Laye

(The letter "W" is used to represent the two letters "v" in vide voyageurs, "empty of passengers.)

The second letter corresponds to the stations served. The letter "E" indicates a train calling at all stations (omnibus, only on the route Saint-Germain-in-Laye - Boissy-St-Léger).

The third and fourth letters are used to form a pronounceable name. These letters are changed when the service number (from 01 to 99 eastward, from 02 to 98 westward) reaches the maximum. Therefore, two services with the first two letters identical serve the same station, e.g. ZEUS and ZEMA (local trains with destination Saint-Germain-en-Laye, or NELY, NEGE and NEMO (local trains with destination Boissy-Saint-Léger. 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 Periods

Each of these services operates 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 stops except Bry, Neuilly-Plaisance and Nanterre-Préfecture.
* Cergy - Torcy, all stops except Maisons-Laffitte, Houilles, Noisiel and Lognes.
* Poissy - Chessy, all stops except Neuilly-Plaisance and Bry.
* St-Germain - Boissy, all stops except Le Vésinet-Centre and Chatou-Croissy.
* Le Vésinet-Le Pecq - La Varenne, all stops except Nanterre-Préfecture, Vincennes and Fontenay.

Evening Peak Periods

Each of these services operates every 10 minutes:
* Cergy - Noisy-le-Grand, all stops except Maisons-Laffitte and Houilles.
* Poissy - Chessy, all stops except Sartrouville, Bry, Noisiel and Lognes.
* St-Germain - Boissy, all stops except Nanterre-Ville and Nanterre-Préfecture.
* Le Vésinet-Le Pecq - La Varenne, all stops except Vésinet-Centre and Chatou-Croissy.
* La Défense - Torcy, all stops except Neuilly-Plaisance and Bry.
* Chessy - Poissy, all stops except Bry and Neuilly-Plaisance.
* Boissy - Le Vésinet-Le Pecq, all stops.
* Noisy - Cergy-le-Haut, all stops except Houilles and Maisons-Laffitte.
* La Varenne - St-Germain, all stops except Fontenay, Vincennes, Nanterre-Préfecture, Chatou-Croissy and Le Vésinet-Centre.

Off-Peak Hours

Each of these services operates every 20 minutes:
*Cergy-le-Haut - Chessy.
*Poissy - Torcy.

This service operates every 10 minutes:
*St-Germain - Boissy-St-Léger.

ee also

* List of stations of the Paris Métro
* List of stations of the Paris RER

External links

* [http://ratp.fr/ RATP official website] "(in French)"
* [http://www.ratp.info/informer/anglais/index.php# RATP official website] "(in English)"
* [http://www.ratp.info/orienter/cv/carterer.php Interactive Map of the RER (from RATP's website)]
* [http://www.ratp.info/orienter/cv/carteparis.php Interactive Map of the Paris métro (from RATP's website)]
* [http://membres.lycos.fr/mobidf/ Mobidf website, dedicated to the RER (unofficial)] "(in French)"
* [http://www.metro-pole.net/ Metro-Pole website, dedicated to Paris public transports (unofficial)] "(in French)"