Paris Line E Extension Faces New Setbacks Due to Traffic Management Issues

According to a recent publication by Railway Gazette International, SNCF Réseau and Alstom have decided to temporarily halt the implementation of the ATS+ traffic management system for the western segment of Paris’s RER Line E.

This progress marks another hurdle in the aspiring Est-Ouest Liaison Express project aimed at extending RER Line E westward. Initially launched in 2016 with a budget of €3.7 billion, expectations were set for completion by late 2022. However, projections now suggest that it could be delayed by seven years, with costs ballooning to at least €5.4 billion.

The Éole initiative involves extending Line E from Haussmann-Saint-Lazare to Mantes-la-Jolie, which includes constructing an additional 8 km tunnel connecting these two points. While this new section is set to open in May 2024, work continues on integrating RER trains into the existing main line corridor leading westward.

This central segment of Line E has been designed to accommodate up to twenty-two trains per hour during peak times. To achieve this capacity between Nanterre and Pantin in the inner eastern suburbs, SNCF Réseau has implemented CBTC (Communications-Based Train Control) technology along with ATO (Automatic train Operation).

The currently functioning part of Line E runs from east through Paris towards Nanterre and is overseen from that same integrated control center at Pantin. However, Siemens Mobility’s NExTEO CBTC system—established under a €186 million contract signed back in February 2016—is only operational within this core area.

Aiming for improved train flow management across other sections of the route, SNCF Réseau planned on deploying ATS+, an advanced traffic management tool distinct from NExTEO’s own systems. One key role of ATS+ would be regulating train schedules and optimizing access into the central core so that those ambitious twenty-two trains per hour can indeed run smoothly.

The rollout plan included two contracts: one managed by Siemens Mobility on the eastern side and another handled by Alstom on the western end near Mantes-la-jolie. While progress is being made between Pantin and Val-de-Fontenay/Le Raincy through regular engineering sessions, challenges persist particularly at the western end where complexities abound.

Citing local media reports on july 3rd regarding potential cancellation claims about their western contract as inaccurate, both Alstom and SNCF Réseau clarified they are merely pausing work while they reassess how best to move forward—including reviewing commercial agreements related to ATS+ implementation there.

SNCF Réseau emphasized that this pause does not impact ongoing or future deployments related to NExTEO CBTC across its network; limited service along Line E could potentially commence between Nanterre and Mantes-la-Jolie around mid-2027—with full operations supported by either ATS+ or similar technologies anticipated before year-end in 2029. p>