The switch, used for trains to change tracks, was taken out of service for safety reasons. This resulted in the interruption of traffic on track 1 bis. Trains were rerouted to use track 1, causing four stations in the direction of Brétigny to be skipped: Savigny-sur-Orge, Épinay-sur-Orge, Sainte-Geneviève-des-Bois, and Saint-Michel-sur-Orge. Trains ran directly between Juvisy-sur-Orge and Brétigny.
This restriction also necessitated an adjustment to the transport plan, including the cancellation of four trains departing from Paris-Austerlitz. The situation was scheduled to be resolved with the replacement of the switch during the night of Thursday, November 12, to Friday, November 13.
Normal train service resumed on Friday, November 13, starting at 5 AM.
