Between Gare d’Austerlitz and Javel, RER C resumes normal activity August 27. You will only see a diagram of the stations affected at the bottom of the stairs to the platform. Plan on buses or other metro lines to circumvent this summer riddle.
Posters are plastered all over the metros and RER about RER A with only a mention that something is going on with RER C. Even at Gare d’Austerlitz the information is limited. With digging, I was able to find maintenance information about the other RER works scheduled. Use Google Translate to read the page.
I was heading to the Eiffel Tower (Tour Eiffel) area, for example. I took line 10 (Boulogne) to La Motte-Picquet-Grenelle, changed to line 8 (École Militaire). The search engine RATP journey planner suggests walking from La Motte-Picquet-Grenelle (16 minutes) to the Eiffel Tower.
RATP Visting Paris page in English provides travel information and a Next Stop Paris travel and advice application.
For the summer, add an extra half-hour to your journey in case of any surprises or “colis suspect” (suspicious package a voyager leaves behind and that must be blown up). On this RATP page (Pourquoi le trafic est-il perturbé en cas de découverte d’un colis suspect?) is a simple info graphic that describes why traffic is disrupted when a suspicious package is found.