A signalling failure at La Défense (Hauts-de-Seine) on Friday June 6, 2025 is causing major disruption on Transilien lines L, N and U. SNCF has announced a partial interruption of traffic on lines N and U, as well as major disruptions on line L.
A signaling failure at La Défense is severely disrupting rail traffic in the Île-de-France region this Friday, June 6. Transilien lines N and U are partially disrupted, while line L is experiencing numerous slowdowns.
Which lines are affected?
- Line N: Traffic is interrupted between Suresnes Mont Valérien and La Défense until 10 am. On the rest of the line, slowdowns are to be expected.
- Line U : Traffic is also interrupted between Suresnes Mont Valérien and La Défense until 10 a.m., with slowdowns on other sections of the line.
- Line L : After a brief interruption, traffic has resumed, but remains severely disrupted between Paris-Saint-Lazare and Versailles Rive Droite / Saint-Nom-la-Bretèche in both directions. SNCF points out that trains can continue to run under cover of a safety measure applied to each train, resulting in significant slowdowns.
What are the alternatives for travellers?
SNCF advises users to check traffic conditions in real time on official platforms such as SNCF Connect or the Île-de-France Mobilités app. Alternative routes via RER A, metro line 1 or streetcar T2 may be considered to bypass the affected areas.
When will things be back to normal?
SNCF expects traffic to resume gradually from 10am. However, delays and disruptions may persist beyond this time. Travelers are advised to consult regular updates to plan their trips accordingly.
To follow the situation in real time, visit the SNCF Connect website or the dedicated mobile application.
