Due to delays on Line 15 South, Line 18 will become the first of the four new lines of the Grand Paris Express to officially open! If everything goes according to plan, the first section of Line 18, connecting Massy-Palaiseau to Christ de Saclay, is set to welcome its first passengers in October 2026. In the following year, the segment between Massy-Palaiseau and Orly Airport will also open. Lastly, it will be 2030 before the line links Christ de Saclay to Versailles - Chantiers.
The progress of the project is quite impressive. Construction began in 2020, and the first test runs of the metro took place on December 18th. A train was able to run along the viaduct for the first time, marking an important milestone towards the launch of Line 18. To celebrate this achievement, the teams from the Grand Projects Society, responsible for designing and building the Grand Paris Express, were on site to oversee what is described as a groundbreaking operation: "the first time such an operation has been carried out on an aerial structure within the Grand Paris Express network," according to a press release.
During this key phase, the focus is on testing whether a moving train can tow a stalled one. Various drills are also conducted, including braking and acceleration tests up to 30 km/h. What's next? The introduction of automatic metro operation, scheduled for early 2026, followed by the much-anticipated 'white run'—a trial run without passengers—before the official launch of Line 18, expected to connect Massy – Palaiseau in Essonne with Christ de Saclay in October 2026.
It's worth noting that Line 18 of the Grand Paris Express will pass through several municipalities in the Essonne and Yvelines regions—including Saclay, Orly, Antony, Massy, Saint-Quentin-en-Yvelines, and Versailles. In total, 10 stations will be accessible via this new line. When the first phase begins operation, commuters will be able to hop off at stations such as Christ de Saclay, Université Paris-Saclay, Polytechnique in Palaiseau, and Massy - Palaiseau, providing connections to RER B and C, the Transilien line V, tram T12, and the Massy TGV station. Notably, Line 18 will feature a 14 km elevated stretch between Palaiseau and Saclay, made possible by a 6.7 km viaduct—the longest in France!
Official website
www.societedesgrandsprojets.fr
