Construction work on RER A this summer
This summer, due to renovation work on RER A, traffic will stop from July the 23rd to August 21st; between La Défense and Nation.
(Source : http://travaux-ete-rera.ratp.fr/fr/)
La Défense and Nation,will become temporary the ends of the RER and still be open for the other connections which will be kept. However, the platforms of the RER A will be closed at Charles de Gaulle-Étoile, Auber, Châtelet-Les Halles and Gare de Lyon.