EOLE ( Est Ouest Livraison Express): this is an Ile-de-France project we've been hearing about for several years now. Declared to be in the public interest on January 31, 2013, it involves extending the RER E westwards to Mantes-la-Jolie in the Yvelines department. With a total of 55 kilometers of new or upgraded track, the new RER E line will offer users an alternative to the RER A, whose central section is regularly saturated. In future, thanks to this extension, journey times between Mantes-la-Jolie and La Défense will be reduced to 40 minutes, compared with 55 minutes at present.
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.
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).
So, when is the operation of the extended RER E line to Mantes-la-Jolie scheduled? Unfortunately, construction has faced further delays. According to Le Parisien and Carrières Mag, the full commissioning of this extension has now been pushed back to "at best, the end of 2029." However, a "partial operation with only a few trains" is expected to start from January 2027.
In the meantime, the test run has begun. As reported by the websites Defense-92.fr and rer-eole.fr, full-scale trial operations of the new generation RER NG trains have kicked off on the section between Houilles-Carrière-sur-Seine and Epône-Mézières stations. The goal of these real-world testing runs? To ensure the trains' proper functionality and to "address any discrepancies" before the planned passenger service launch in 2027. These tests are conducted without passengers, early in the morning, and do not affect the existing service, as clarified by the EOLE project website.
Official website
www.rer-eole.fr
