RER E Line Extension (Eole) Project Profile: Paris, France

The RER E Line Extension, known as the Eole (Est-Ouest Liaison Express) project, is a transformative railway infrastructure initiative enhancing east-west connectivity across the Île-de-France region. This profile details the technical specifications of the 55 km western extension, including its 8 km core tunnel under Paris, new stations, and the deployment of next-generation signalling technology. The project is designed to significantly increase network capacity, reduce journey times, and alleviate congestion on parallel transit lines.

Technical Specifications

The core of the extension is a new 8 km twin-bore tunnel connecting the existing Haussmann-Saint-Lazare station to Nanterre. This required sophisticated tunnel boring machine (TBM) operations beneath a dense urban environment. The project includes the construction of three new state-of-the-art stations: Porte Maillot (Palais des Congrès), La Défense-CNIT, and Nanterre-la-Folie. The La Défense station, constructed beneath the iconic Centre for New Industries and Technologies (CNIT), represents a significant civil engineering achievement, integrating the new railway hub with a major commercial and business district.

Operationally, the line is a showcase for advanced railway technology. It is equipped with Siemens’ NExTEO Communications-Based Train Control (CBTC) system, an automated train operation (ATO) system that enables high-frequency service of up to 28 trains per hour. This technology is critical for managing the dense traffic flow through the central corridor. The new RER NG rolling stock, designed specifically for this line, complements the advanced signalling to ensure high performance and passenger comfort. Station infrastructure emphasizes accessibility and reliability, with 75 escalators and moving walkways managed by the “Doctor Step” predictive maintenance system to maximize uptime.

Key Takeaways

• Decongestion of Central Paris Network: The extension is projected to reduce passenger load on the heavily saturated RER A line by 15%, while also providing relief for RER lines B and D and the Saint-Lazare suburban rail hub.
• Enhanced Westward Connectivity: By extending the line to Mantes-la-Jolie, the project directly connects Paris’s central business districts with the western suburbs and the La Défense business hub, significantly cutting journey times for over 650,000 daily commuters.
• Technological Benchmark for Urban Rail: The implementation of the NExTEO CBTC system establishes a new standard for high-capacity, automated operations on the Parisian network, paving the way for future modernization projects.

Frequently Asked Questions (FAQ)

When will the full RER E extension be open?

The first phase of the RER E extension, connecting Haussmann-Saint-Lazare to the new Nanterre-la-Folie station, became operational in May 2024. The final phase, which extends the line further west to Mantes-la-Jolie, is scheduled for completion by the end of 2026.

Who is building the RER E extension?

The project is managed by SNCF Réseau, the French national railway infrastructure manager. Key delivery partners include SYSTRA for design and engineering, Siemens for the NExTEO signalling system, and a consortium led by VINCI Construction and Spie batignolles for the construction of major sections like the La Défense station. Otis France is responsible for the extensive escalator and lift systems.