Branches Line A provides two groups of services: • St Germain branch – common trunk line – Marne-la-Vallée branch • Cergy or Poissy branches – common trunk line – Boissy-saint-léger 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
peak periods, 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 RER trains display a
mission code rather than 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)'': 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
Saint-Germain-en-Laye –
Boissy-St-Léger (NELY or ZEUS); • with first letter "Q",
Poissy to
Marne-la-Vallée–Chessy, all stations except
Neuilly-Plaisance and
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 Boissy-St-Léger 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 Saint-Germain-en-Laye), or NEGE, NELY and NEMO (to Boissy-St-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 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 ==