Publié le 27/10/2016 - Mis à jour le 20/07/2017
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RER E – soon one train ahead thanks to NExTEO …

A very innovative operating system will soon be used by both the infrastructure and trains of the future RER E commuter line (EOLE project). Known as NExTEO, it brings the promise of better regulation and an increased capability of managing traffic disruptions. Based on leading edge technology, NExTEO will increase the frequency of trains and better coordinate traffic, thereby improving railway service for passengers. More trains, faster trains and better regularity … Significant time savings are on the horizon!

Eole – a line which will revolutionise mobility

Guillaume is waiting for his train on the platform at the Rosa Parks station of the RER E commuter line in the northwest of Paris.

He is going to Nanterre, situated in a western suburb of Paris, to attend a meeting about “Eole”. The meeting will take place on the site on the future railway station of Nanterre-La Folie. Guillaume is part of the team of this major project whose leadership is under the responsibility of SNCF Réseau. The project involves extending the current RER E line by 55 km to the west to Mantes-la-Jolie. Once completed, this line will contribute to the decongestion of the RER A line between Auber and La Défense, the RER B and D lines between Châtelet and Gare du Nord, and the Saint-Lazare railway station in Paris. The new RER E line will be connected to all RER Express lines, most underground stations and the future lines 15 and 18 of the Grand Paris Express. It will transform the mobility of 620,000 Ile-de-France passengers that will take this line after it is commissioned in 2024, and more generally the life of millions of Ile-de-France travellers thanks to increased railway network coverage and a reduction in required line changes. 

The extension of the RER E line to the west of Paris will improve the mobility of millions of passengers.
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In the meantime, however, to get to Nanterre-La Folie, where a train parking centre and maintenance site are scheduled to be constructed, Guillaume must first go to the Hausmann Saint-Lazare railway station, which is currently the last station of the RER E line. He must then walk to Auber to take an RER A line train to go to Nanterre-Préfecture.

"This line will contribute to the decongestion of the RER A line and the Saint-Lazare railway station"


NExTEO – the right technical solution

While walking to the platform of the RER A line, Guillaume is certain that with the future RER E line [Lien externe vers] the STIF transport authority for the Ile-de-France region, which initiated this project, has found an effective solution to East-West commuting in the Paris area. Nonetheless, the major innovation is the NExTEO traffic regulation and signalling system which will be used by the future RER E line. When this new system is deployed in 6 years on the central section between the Rosa Parks and Nanterre-la-Folie stations, it will provide a wide range of functionalities:

  • a higher number of trains in circulation (an interval of 108 seconds between trains) travelling at faster speeds (up to 120 km/hr)
  • support for regulation and rail incident management
  • automation of the traction and braking phases of a train

There will be a host of improvements which passengers will greatly appreciate – regularity, punctuality and real-time information. For example, the time saved to go from Rosa Parks to Nanterre will be 33 minutes!

To meet this ambitious challenge:

  • SNCF Réseau and SNCF Mobilités have set up a common project leadership team which includes all the required expertise (operations, maintenance, traction, safety, systems, etc.).
  • Project management is being carried out by a techical association called I3G, which includes experts from SNCF Réseau (Engineering and Projects), SNCF Mobilités and RATP Engineering, which has extensive experience in automated train operations.

The aim is to apply software functionnalities used by automated metro systems to train travel.

As Guillaume hurries along the corridors of the Saint-Lazare railway station, he remembers what he was told by Xavier Gruz, the Eole Project Director: “Thanks to NExTEO, it will be possible to have very high traffic flow in the highest intensity traffic situations. This ambitious achievement will be made possible as the system reduces the interval between trains to 108 seconds, compared to 180 seconds for traditional signalling. This means that it will be possible to have up to 28 RER trains per hour in circulation, almost one train every two minutes! Traffic flow will also be easier to manage as it will be possible to slow down and speed up trains in an optimal manner, according to traffic needs. For example, a train that stopped for longer than planned in a station will be able to make up the time it lost in the following section.”

"Increase the frequency and speed of trains, and increase their regularity"


A major technological innovation

SNCF Réseau and SNCF Mobilités selected an innovative train assistance automation technology, called Communications-Based Train Control (CBTC), to automate the different tasks. Siemans France will develop and deploy this train control system. To this end, it will also use the following:

  • its automatic train supervision system called ATS Vicos CBTC 
  • its secure radio communication system called Airlink

This solution is based on continuous radio exchanges between the trains and a central intelligence point. It has already been deployed as part of metro line modernisation programmes in Paris, New York, London and Copenhagen. It operation is based on each train itself detecting and calculating its own position on the line, and then transmitting this information to a central intelligence point. Central intelligence then assigns it a point to be protected, which corresponds to the rear of the train in front of it. The system therefore manages the safety spacing between trains and determines the optimal speed. In addition, central intelligence is able to update all passenger travel information tools in real time.

To carry out this project, Siemans concluded a partnership with ATOS, a company specialised in digital technologies and train network supervision systems.

"This solution is based on continuous radio exchanges between trains and a central intelligence point"


The future is now

Guillaume has arrived at his destination. He is on time for his meeting.

While crossing the huge work site in the Groues sector – an area currently being redeveloped in particular as part of a sustainable developement project – he thinks about another (lesser known, but important) advantage of NExTEO:  energy-efficient train control. In its traffic regulation algorithms, the interface will include an objective to reduce as much as possible the energy required for the operation of the train.

"The system will optimise the operation of trains in order to reduce energy consumption"

How is the Eole project being financed?

The Eole project, and future RER E line, is being financed by the following:

  • French state
  • Ile-de-France region
  • SGP Grand Paris
  • City of Paris
  • Yvelines Departmental Council
  • Hauts-de-Seine Departmental Council
  • SNCF

The STIF (transport organisation authority in the Ile-de-France region) is monitoring compliance with project budgets and work schedules, and is financing 100% of the rolling stock and onboard NExTEO system.

Find out more about the project financing on the RER Eole web site.