A major milestone has been reached for Europe’s largest urban rail project: the first fully automated metro train for Paris’s upcoming Line 18 has arrived at the Palaiseau maintenance depot in the southern Île-de-France region. Built by Alstom across six sites in France, the 47-meter-long trainsets—made from 20% recycled materials—can carry up to 350 passengers and promise accessibility, connectivity, and comfort. Their arrival marks the beginning of extensive test operations on the dedicated test section of the line. Line 18 is scheduled to enter service in late 2026, connecting Orly Airport with the Paris-Saclay innovation cluster.
183 trains in delivery
For the Grand Paris Express project, Alstom is supplying a total of 183 fully automatic metro trains for lines 15, 16, 17 and 18. 152 MR6V series vehicles with six carriages, which are 108 metres long and can carry up to 960 passengers, are planned for lines 15, 16 and 17. Line 18 will receive up to 37 shorter MR3V trains with three carriages and a length of 47 metres, which can carry up to 350 passengers. All trains have air conditioning, panoramic windows, USB charging ports, WLAN and are completely barrier-free. They are manufactured at several Alstom sites in France and are designed for automated operation without a driver.
2025: From Construction to Commissioning Across the Grand Paris Express
Throughout 2025, all four Grand Paris Express lines—15, 16, 17 and 18—are either entering or advancing through the testing and equipment installation phase, the final step before commercial operation begins:
- On Line 15 South, testing of systems, rolling stock, and automation began in late 2024 and will gradually expand along the entire line. Commercial operation is now scheduled for late 2026, nine months later than originally planned.
- On Lines 16 and 17, station outfitting is ongoing, including escalators, platform screen doors, and ventilation systems. In the tunnels, critical systems such as radio beacons, fibre optic cables, and electrical infrastructure are now being deployed. The first trainset has already been delivered to the operations center in Aulnay-sous-Bois.
- On Line 18, the first trains are undergoing testing at the national railway test center in Valenciennes and are expected to arrive at the Palaiseau depot by summer 2025.
After more than six years of civil engineering work and station construction, the lines are now entering a less visible but technically complex phase: the integration and testing of critical systems. On Lines 16 and 17, between Saint-Denis–Pleyel and Clichy–Montfermeil and Le Bourget–Aéroport, station infrastructure is taking shape while behind the scenes, crews are installing ventilation systems, fibre networks, ticketing equipment, and platform facades—all essential to operational readiness.
Revised Timeline
Despite visible progress, the project timeline was reassessed in late 2024 by the Société des Grands Projets (SGP). Due to the complexity of system integration and initial automatic test runs on Line 15, its opening has been delayed to Q4 2026. As Lines 15, 16, and 17 share the same control systems, the revised plan requires a six-month gap before Lines 16 and 17 can begin service—shifting their first segments to Q2 2027. Subsequent phases of Lines 16 and 17 remain scheduled between 2028 and 2031.
SGP admitted that the shift from civil works to technical commissioning had been underestimated. Initial test runs revealed additional challenges, prompting the need for an updated, realistic schedule—confirmed by an external technical audit. A new action plan is being implemented to optimise the coordination of the final project phases and better manage the risks associated with system testing and handover.
Political impact
The delays have drawn strong criticism. Valérie Pécresse, president of Île-de-France Mobilités, expressed disappointment and concern over recurring schedule slippages. She has called for the establishment of a joint State/Île-de-France oversight and coordination mission to prevent further delays and ensure transparent reporting.
A technical report commissioned by Pécresse, known as the Ramette/Bense audit, highlights serious coordination issues, particularly on Line 15. It cites delays in structural works and a lack of integration between various phases and industrial contracts. The audit also confirms that Lines 16 and 17 are inherently affected due to their reliance on shared test infrastructure.
Pécresse is calling for closer involvement of all operators—RATP GI (infrastructure) and ORA/Keolis (operations)—to ensure smooth transitions and avoid operational delays similar to those encountered during the opening of Line 14’s latest extensions. She has also asked for the audit to be extended to Line 18, which uses a separate supplier base and technology platform.
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