On 17 June 2025, the Société des grands projets, Île-de-France Mobilités, and Alstom formally presented the first metro train for Line 18 of the Grand Paris Express, following its delivery to the Palaiseau operations centre.
This milestone signals the start of the testing phase ahead of the partial opening of the line between Massy–Palaiseau and Christ de Saclay, planned for late 2026.
This train is part of a broader procurement of 15 trainsets, funded by Île-de-France Mobilités through a 199 million EUR investment. Ten trainsets will operate on the initial section of the line, while the remaining five will be deployed on the extension to Orly Airport, expected to open by the end of 2027.
Following earlier tests at Alstom’s production facility and the Centre d’Essais Ferroviaires in Valenciennes, operations are now transitioning to the dedicated infrastructure at Palaiseau. The tests will be supervised from the centralised command post, which was completed in spring 2025, with Alstom installing supervisory systems.
By the end of the year, ten trainsets are expected to be delivered to Palaiseau, enabling dynamic testing to extend across the full 8.5 kilometre stretch between Massy–Palaiseau and Christ de Saclay. These tests will assess the interaction of the rolling stock with infrastructure components such as platform edges, passenger information systems, and communications between trains and trackside systems.
Design work for the new rolling stock was carried out by Alstom in coordination with Île-de-France Mobilités, the Société des grands projets, and Egis Rail. The trains feature wide doors, a continuous low floor, and dedicated areas for passengers with reduced mobility. Large windows and LED lighting contribute to visibility throughout the train, while the layout has been informed by ergonomic studies. Other amenities include USB charging ports, real-time information displays, and intelligent air conditioning.
Each train consists of three cars, measuring 47 metres in total length and 2.5 metres in width, with space for up to 350 passengers.
Line 18 is one of the new fully automated metro lines being delivered as part of the Grand Paris Express project. Spanning approximately 33 kilometres, it will connect ten new stations, including three on an elevated section. The route is designed to link with existing rail services, such as metro line 14, RER B and C, tram lines T7 and T12, and regional train lines N and U.
When operational, Line 18 will be fully electric and driverless, with trains running as frequently as every 90 seconds during peak periods. Trains are expected to travel at an average speed of 65 km/h, reaching up to 100 km/h. The traction system uses a 1,500 V third rail with reverse collection, a configuration chosen to minimise the visual impact of the overhead section and avoid the need for overhead lines.
With testing now underway and infrastructure nearing completion, the focus over the coming months will be on verifying system compatibility and reliability. The successful integration of the rolling stock and control systems will be a determining factor in the readiness of the line for passenger service, currently anticipated to begin in late 2026 for the initial section.
Once in service, Keolis, appointed by Île-de-France Mobilités, will take over operations.
