New delays for future lines 15 south, 16 and 17 of the Grand Paris Express

Work on metro lines 15 south, 16 and 17 of the Grand Paris Express network has been delayed again, the Société des Grands Projets (SGP) announced on Tuesday 18 February, prompting the president of Ile-de-France Mobilités, Valérie Pécresse, to request a "monitoring mission".

Linked to technical difficulties, six additional months of delay bring the delivery of line 15 south (Noisy-Champs to Pont-de-Sèvres) "to the fourth quarter of 2026", detailed the chairman of the board of SGP Jean-François Monteils during a press conference. It had already been postponed in November to the summer of 2026.

The first sections of lines 16 and 17, from Saint-Denis to Clichy and Le Bourget, will be delivered in the "second quarter of 2027", whereas they were expected at the end of 2026.

The first tests on line 15 south revealed adjustments to be made to the software, explained the SGP.

"The work cannot be done simultaneously on line 15 south and on lines 16 and 17," justified Mr. Monteils, pointing out "an irreducible delay of around six months" between them.

Valérie Pécresse said she was "shocked by the scale of the new delays".

There is "now a risk of not having delivery of the line [15 south] before April 2027", she worries in a press release. This is "very bad news for the hundreds of thousands of residents and workers in the inner suburbs".

It calls for "the creation of a monitoring and coordination mission to reduce these additional delays as much as possible by the end of 2026 and to ensure precise and transparent information, in real time, for the members of the SGP supervisory board".

For the president of the Seine-Saint-Denis department, Stéphane Troussel (PS), "every month counts so that finally all the inhabitants of Seine-Saint-Denis benefit from access to quality transport, and thanks to them to all the employment opportunities, education and essential services", according to a press release.

The SGP indicated that it had relied on a report by Yves Ramette (former general director of RATP) and Didier Bense (former CEO of SNCF for the Ile-de-France region) to establish a new schedule, which it is "convinced is robust", stressed Bernard Cathelain, member of the SGP board of directors.

To explain these delays, the SGP insists on the new nature and scale of the Grand Paris Express. The deadlines planned for these testing and systems appropriation phases "were not sufficient", the management argues.

These delays do not affect the northern section of line 15, passing through La Défense and Seine-Saint-Denis, nor the following sections of line 17.