This will be the first time the European Rail Traffic Management System (ERTMS) is installed on existing tracks in France. The Marseille - Ventimiglia High Performance Rail Network (HPMV) project—funded by the European Union, the French government and SNCF Réseau—will be a showcase for modernizing France’s railway infrastructure. As work gets under way, we talked with project manager Jacques Paulet to find out how this new traffic management system will increase capacity and help standardize the European railway network.

Jacques Paulet: Between Marseille and Ventimiglia, we use the BAL/KVB automatic block signaling system, which dates back to the 1960s. But one of SNCF Réseau’s top priorities is a centralized operations centre, and for that we need digital technology.

Exactly. We’ve made a joint decision to install ERTMS, the European signalling standard designed to usher in railway interoperability. But we also needed to the line to handle more trains, since both passengers and the Regional Council were demanding more capacity than we can currently provide. The existing signalling system makes it complicated to run different kinds of trains—TGV and TER, for example—on a single line. We max out at 5 trains per hour, which isn’t enough to meet growing demand.

Jacques Paulet: It lets us run trains every 1 and a half to 2 minutes, compared with a 4 to 5 minutes today, which means it cuts headway between 2 trains in half. We’ll be able to pack schedules and timetables much more efficiently. The French government and SNCF Réseau wanted this heavily travelled corridor to serve as an example as we get ready for a much more systematic and broader adoption of ERTMS. It will be a showcase for modernizing France’s railway infrastructure over the coming decades.

We won’t have to acquire any land or do any civil engineering works to install ERTMS on this line—and yet, it promises a two-fold increase in rail traffic.

Jacques Paulet: There are 3 phases, one for each French department the line passes through: Alpes-Maritimes, Var and Bouches-du-Rhône. The Alpes-Maritimes phase will begin in late 2027, and the entire project will finish up in late 2030. Which means that by those dates, trains will need to have ERTMS installed so they can run just as soon as we launch the new system and “unplug” the old one.

Jacques Paulet: For phase 1 in the Alpes-Maritimes, at the Italian border, we received French government backing in round 4 of the Investments for the Future Programme (PIA), known as France 2030. We qualified because we’re a test case promoting innovation to build a fully digital rail network. That funding amounts to around €100 million. The EU is also kicking in €43 million, and the rest will come from SNCF Réseau’s network regeneration budget.

There are 2 options: either upgrade existing trainsets to install the new ERTMS signal decoders onboard or buy newly built rolling stock with the right equipment already installed. We’re doing both. The Sud Regional Council, which is responsible for regional transport planning, has funded upgrades to 31 trainsets and will be buying 15 new trainsets for delivery in 2025.

There won’t be much impact for customers. We’re doing all the work behind the scenes, outside of normal operating hours, so the network is running as usual. The work near Cannes and Grasse involved installing radio antennas, digging trenches under the tracks and so on. You’d never know we were there! At the same time, industrial partners like Hitachi, Atos Eviden, Thales and Frauscher are building the technical components: the new digital switching station in Marseille, ERTMS and signalling calculators, axle counters, and so on.

Jacques Paulet: In 2027, we’ll suspend service for a few days to bring the system on line from Cannes to Ventimiglia and do all our safety checks. That stretch is incredibly important because it’s used by TER, TGV and overnight trains, and also has depots, train yards, and other facilities. Switching and signalling under those conditions is complicated. We want to have even fewer network disruptions during phases 2 and 3, in the Var and Bouches-du-Rhône departments.

Jacques Paulet: The Paris - Strasbourg, Tours - Bordeaux and Le Mans - Rennes lines were all new, so they already had the right infrastructure. And there were no major train stations on those routes, which simplified the technology side of things. We are really on the cutting edge, even at European level, when it comes to retrofitting our existing stations with new technology.

The sheer complexity of equipping the Nice station with ERTMS means that the Marseille - Ventimiglia line can act as a case study for other rail sites in France. We’ve already examined the Nantes and Rouen stations, for example, to make sure our design approach is something we can repeat.

Jacques Paulet: The HPMV project is a game-changer for the entire railway industry with respect to traffic and signalling equipment maintenance. And it will radically alter the way we drive trains, naturally. Going forward, everything is based on IT systems, requiring an entirely new set of job skills that draws on telecoms expertise. Drivers using ERTMS won’t be looking out the window for signal lights anymore. Intead they’ll be watching the dashboard screens inside the train.

It’s a revolution stemming from the masses of data that various systems can now collate in real time or with a delay. These systems will help with maintenance, driving, crisis management, and more. Our trains will be safer because onboard systems will interact with level crossings, and the switching station will be constantly monitoring traffic. Drivers will receive information in real time. That isn’t the case today—they have to wait until they reach a signal to get instructions.

Jacques Paulet: With 100% digital systems, we can build in redundancy in case there’s an outage. Today, it’s impossible to have a backup switching room because they use thousands of relays. In future, we’ll have an automated train protection (ATP) unit the size of a computer onboard, backed up by a second unit that can take over if the first one fails. Digitalization allows us to have backup equipment that makes the whole system more robust and reliable.

Jacques Paulet: If we were using traditional signalling systems for this project, it would generate 70% more CO₂. And since we’re eliminating signal lights and switching will be centralized in Marseille rather than spread out over several sites along the route, we’ll use a lot less energy.

ERTMS will also eliminate most issues with track/platform length at train stations. For that alone, implementing ERTMS will save us several tens of millions of euros.

Jacques Paulet: This project has started a very constructive dialogue between SNCF and Rete Ferroviaria Italiana (RFI). Because the line doesn’t stop at the border, we’re working closely with our Italian counterparts who are managing the project from the border to Genoa. By 2028, the system will cross over, and the two regions—Sud and Liguria—will be able to run trains over longer distances without changing at Ventimiglia. Note that this is case of us choosing to pursue a joint ERTMS project. It hasn’t been imposed by Europe from the top down.

This project will increase capacity on the line and make it possible to schedule more trains. But we also want it to build closer cross-border ties so we can meet the needs of Italians travelling in France and French passengers heading to Italy, for both holiday and business travel. In that sense, we really are taking a big step towards European rail interoperability.