The latest meeting of the monitoring board for the Société des grands projets provided updates on the progress of the Grand Paris Express, a major public transport project aimed at improving mobility across the Paris region. While some developments were positive, others raised concerns. The first section of line 18, which is expected to be the first part of the Grand Paris Express to open, is now projected to be completed in December 2026—just a few days after the official inauguration date mentioned by Valérie Pécresse, president of the Île-de-France region, during her address on November 30. Line 15 Sud, a key component of the project, continues to face challenges, which are affecting the progress of lines 16 and 17 as well. These delays highlight the complexity of coordinating multiple phases of the project simultaneously. Meanwhile, line 18 has been in the final testing phase since September to ensure its transportation system meets all required standards. This testing is crucial for confirming the line’s readiness for public use. The transfer of technical management of line 18 is still scheduled for October 13. Once this transfer is complete, the operator, Keolis, will be able to begin the trial phase of operations. This trial phase is an important step before the line opens to the public, allowing for any necessary adjustments to be made based on real-world performance. The state services are still processing the safety file for the transportation system, a critical document that ensures the project meets all safety regulations. The file was first validated on September 3, but additional work remains to be completed before the line can be officially approved for operation. This final step underscores the importance of ensuring public safety and regulatory compliance as the project moves closer to completion.