RER E: When will the extension to Mantes-la-Jolie open?

EOLE (East-West Express Service): this is a project in the Île-de-France region that has been making headlines for several years. Declared to be in the public interest on January 31, 2013, it will extend the RER E westward to Mantes-la-Jolie in the Yvelines department. With a total of 55 kilometers of new or renovated track, the new RER E line is set to give passengers an alternative to the RER A, whose central section is regularly overcrowded. In the coming months, thanks to this extension, the journey between Mantes-la-Jolie and La Défense will take 40 minutes, down from 55 minutes currently.

In 2024, two major milestones were achieved: the opening of three new stations — Neuilly-Porte Maillot, La Défense, and Nanterre-la-Folie — in May. However, initially, trains only ran during off-peak hours. It wasn't until December 2024 that this extension to Nanterre-la-Folie hit its stride, offering regular all-day service without the need to change trains.

Another major milestone has been reached: the inauguration, on November 6, 2026, of the new Mantes-la-Jolie maintenance workshop, covering an area of 17,000 m². Billed as a “strategic and innovative industrial facility,” the Mantes-la-Jolie maintenance workshop will house, maintain and prepare 40 of the 130 RER NG (New Generation) trains on Line E.

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What’s next? Soon, Line E of the RER will be extended to reach Mantes-la-Jolie, which will be the new terminus and the final stop of the EOLE project. This extension involves renovating and modernizing the 47 kilometers of existing tracks between Nanterre and Mantes-la-Jolie, aiming to improve the RER E line’s service. It will serve stations including Houilles - Carrières-sur-Seine (with connections to RER A and Line L of Transilien), Poissy (connections to RER A and T13), but also Villennes-sur-Seine, Vernouillet-Verneuil, Les Clairières de Verneuil, Les Mureaux, Aubergenville-Elisabethville, Epône-Mézières, Mantes Station, and ultimately Mantes-la-Jolie (with connections to Transilien lines J and N).

RER E extension to Mantes-la-Jolie: when will it enter service?

So, when is the commissioning of the extension of the RER E to Mantes-la-Jolie expected? At the Île-de-France Mayors' Fair, held on June 2 in Paris, project managers said the RER E will begin commercial service as far as Mantes-la-Jolie on February 28, 2027. From that date, passengers will be able to use this RER line to reach the stations of Houilles - Carrières-sur-Seine, Poissy, Vernouillet-Verneuil, or even Epône-Mézières, not to mention Mantes-la-Jolie, the new terminus of the RER E.

Please note that the rollout will be gradual. Starting February 28, 2027, four trains per hour will serve Mantes-la-Jolie. The ramp-up is expected to continue through the end of 2029, or perhaps into early 2030, with six trains per hour at peak times, according to the Mantes-la-Jolie website.