RER - Future Developments

Future Developments

Extensions to the RER focus on Line E, which ends at Haussmann - Saint-Lazare, serving only one side of Paris, unlike all other RER lines. Various Line E extensions have been proposed:

• westward from Haussmann - St Lazare to Mantes-la-Jolie. Plans for this extension include an eight kilometer bored tunnel from the current western terminus at Haussmann - St Lazare, with new stations at Porte Maillot, La Défense, and Nanterre - La Folie, and a connection to the SNCF Normandy line in or near Nanterre, the transfer of the current Line A Poissy service to Line E, and its further extension down the Seine valley to Mantes.
• eastward from Chelles-Gournay to Esbly and Meaux
• eastward from Tournan to Coulommiers

Until the western section is in service, neither of the eastern extensions can be put into service, because the Haussmann - St Lazare station is currently at its maximum capacity because all trains are currently forced to turn around at this station. Once the western extension is in service, Haussmann - St Lazare will become a through station and the eastern extensions will be possible. One of the primary reasons for the completion of Line E through Paris is to relieve Line A of its excessive ridership, especially at commute times. Plans for the westward extension are in an advanced stage and construction is to begin in 2013, with an inauguration of the new line in 2020.

A new Line E station has been proposed at Rue de l'Évangile (now to be called Rosa Parks) on the approach to Gare de l'Est, with a tentative opening date of 2014.

Older plans existed for a line F, which would connect Argenteuil to Rambouillet via existing tracks of the Saint-Lazare and Montparnasse rail networks. A new tunnel would be bored below Paris, with the creation of a station at Invalides. The cost of the new tunnel and the fact that Saint-Lazare and Montparnasse networks form a loop make this project unlikely to happen.