Passengers at the Mantes-la-Jolie station, in Yvelines (78), will need to brace themselves for a long weekend tied to the National Holiday. From Saturday 11 to Tuesday 14 July 2026, SNCF is carrying out a major operation that disrupts services on Transilien Line J and the Normandy Nomad lines. For the first two days, no trains will run in the town of Mantes-la-Jolie.
The upheaval is well known in the Mantois: the work on the extension of the future RER E, known as Eole, is entering its final phase. The new line, which should by early 2027 replace the current Paris-Mantes via Poissy branch of line J, has yet to welcome passengers at Mantes-la-Jolie—the first services are not expected until the end of February 2027. This time, about 150 staff are being mobilized to connect the new Mantais maintenance workshop to the national rail network.
In practical terms, the teams are laying the final stretches of access tracks to the site, energizing the installations, and linking the new workshop’s switchgear to the station’s historic one. Three platforms are also being raised to accommodate the Nouvelle Génération trains. On the schedule, SNCF is projecting a smooth path forward: only two stations remain to be completed, and the project is on track, says project director Vincent Le Poittevin.
On Saturday July 11 and Sunday July 12, 2026, no trains will serve Mantes-la-Jolie. Between Val-de-Reuil (Eure) and Mantes-la-Jolie, just as between Vernon and Issou-Porcheville, reservation-only buses will take over service up to the Issou station.
On the J line to Paris Saint-Lazare via Poissy, replacement buses are running to all stations up to Les Mureaux, where passengers can hop back on the train. The same arrangement applies on the branch via Conflans-Sainte-Honorine, with service to the stations of Mantes Station, Limay and Issou-Porcheville. Île-de-France Mobilités is also strengthening the regular bus lines between Poissy and Les Mureaux, between Mantes-la-Jolie and La Défense (Hauts-de-Seine), and between Les Mureaux and La Défense.
The return to normal is progressing gradually. Towards Normandy, traffic remains interrupted at the start of the week: buses run between Vernon and Mantes-la-Jolie on Monday the 13th and Tuesday the 14th of July 2026, and from Évreux only on Mondays, still by reservation.
Across both branches of Transilien, service on Monday, July 13, operates with Saturday frequency, with an early evening end to service on the Paris–Mantes via Poissy line. On Tuesday, July 14, a public holiday, trains run at Sunday speed until the evening, after which replacement buses take over between Sartrouville and Mantes-la-Jolie. The bus line 7820 from La Défense is also strengthened during these periods.
Before you travel, we strongly recommend checking your route in the Île-de-France Mobilités app or on the official J line blog, which lays out all works and substitution options. To monitor day-to-day traffic, also check out our piece on the J line disruptions in real time. One thing’s for sure: after the late-June thunderstorms that already tested the line, Mantois commuters will once again be kept on their toes while awaiting the promised benefits of the RER E, due to arrive in early 2027.
Dates and Opening Time
From July 11, 2026 to July 14, 2026
