Société des Grands Projets Achieves 120 km/h High-Speed Automated Dynamic Trials on 33-Kilometre Grand Paris Express Line 15 South Ahead of 2027 Commercial Opening

High-Speed Dynamic Testing Reaches Critical Milestone on Europe’s Largest Megaproject

PARIS, Ile-de-France — In a major technical triumph for European mass transit engineering, the Société des Grands Projets (SGP) has achieved critical dynamic testing milestones on the flagship Line 15 South of the Grand Paris Express. Operating on the 33-kilometre subterranean rail corridor between Pont de Sèvres and Noisy-Champs, automated test trainsets have successfully reached their top operational speed of **120 km/h (75 mph)** during comprehensive closed-network trials, validating vehicle propulsion, high-performance braking, and Communication-Based Train Control (CBTC) systems ahead of commercial passenger service in autumn 2027.

Representing the inaugural segment of the world's most ambitious orbital metro network, Line 15 South traverses 22 municipalities across four departments of the Île-de-France region (Hauts-de-Seine, Val-de-Marne, Seine-Saint-Denis, and Seine-et-Marne), serving 16 architecturally bespoke underground stations.

Fully Automated Driverless Alstom Fleet and CBTC Platform Safety

The service will be operated by a dedicated fleet of Alstom Metropolis MR3V/MR6V automated trainsets, featuring Grade of Automation 4 (GoA4)—the highest standard for completely unattended driverless train operation. During recent dynamic trials, engineering teams subjected the rolling stock to extreme operational scenarios, including emergency braking, steep gradient navigation, low-friction rail response, and high-frequency spacing protocols.

Every underground station along the alignment is equipped with 100% full-height glass Platform Screen Doors (PSDs) synchronized with train door mechanisms, laser-guided obstruction sensors, and real-time biometric passenger flow analytics to ensure uncompromising safety on subterranean platforms.

Transforming Suburban Transit and Eliminating Paris Ring Bottlenecks

Once operational, Line 15 South will revolutionize travel patterns across Greater Paris by providing rapid suburb-to-suburb orbital transit without requiring passengers to route through the congested central stations of central Paris. A journey between Pont de Sèvres and Noisy-Champs will take just 37 minutes, cutting current transit times in half.

The line provides direct interchanges with nearly every major transit artery in the metropolitan region, intersecting with Transilien commuter rail, RER lines A, B, C, D, and E, Paris Métro lines 4, 7, 8, 9, 13, and 14, as well as multiple regional tramways and high-capacity T Zen bus rapid transit corridors. Over 300,000 daily passengers are projected to use Line 15 South upon opening.

Unlocking Sustainable Regional Growth and Slashing 150,000 Daily Car Trips

The commissioning of Line 15 South serves as the catalyst for the wider 200-kilometre Grand Paris Express network, which will eventually encompass Lines 15, 16, 17, and 18. Regional economic forecasts estimate that the orbital line will eliminate upwards of 150,000 private automobile journeys from Parisian ring motorways and outer boulevards each day, substantially curbing regional carbon dioxide emissions and particulate smog.

Île-de-France transport authorities and state planners emphasized that the successful 120 km/h dynamic trials confirm the readiness of France’s cutting-edge rail technology, delivering an enduring, climate-resilient transport foundation for the 12 million residents of Greater Paris.