Grand Paris Express: a new technical setback makes the inauguration of line 18 in 2026 unlikely

On October 13, the Société des grands projets (SGP) handed over the keys of the new metro line 18 to Ile-de-France Mobilités (IDFM). However, the start of the planned testing phase has been delayed as IDFM, RATP, and Keolis deemed safety conditions insufficient. The automation system designed by Alstom is cited as the main issue, leading to underestimations of complexity and subsequent delays. Unless a solution is found soon, the inauguration of line 18 may be postponed to 2026, with regional president Valérie Pécresse expressing regret over the situation.