Grand Paris Express is a group of new rapid transit lines being built in the Île-de-France region of France. The project comprises four new lines for Paris Métro, plus extensions of existing Lines 11 and 14. A total of of new track and 68 new stations are to be added, serving a projected 2 million passengers a day.
The new lines were originally indexed by colour (Red Line, Pink Line, Green Line), but this changed in 2013 to continue the numbering convention that the RATP uses. The new lines are therefore now known as 15, 16, 17 and 18. They are planned to open in stages, starting with the Line 11 extension in Spring 2024 and through 2030.
Since August 2013, the New Grand Paris steering committee has met quarterly. The first public inquiry, focused on the southern section of Line 15 from to Noisy–Champs, was held from October to mid-November 2013. Work on line 15 began in 2015. Its first section between Métro station and Noisy–Champs RER A station was scheduled at that time to open around 2020, but this has now been pushed back to 2025. This line was first proposed in the Orbival project, then integrated into the Arc Express.
Line 11 extension
To ensure better commuter service to the inner Northeastern suburbs, a six-station, eastbound extension of Line 11 is under construction from Mairie des Lilas to Rosny-sous-Bois. The scheme was initially lobbied for by the local authorities of these suburbs, and was adopted during the 2007 review of the Île-de-France Transportation Plan. Work on the extension to Rosny – Bois-Perrier started in 2015 and it is expected to open by the end of 2023. It will provide new connections with the RER E and the extended Île-de-France tramway Line 1, which it will better link to central Paris and the commuter hub of Châtelet–Les Halles.
Revisions in the Grand Paris Express Plan and possible automation
A revised plan for the proposed Grand Paris Express subway system was unveiled on 6 March 2013, and calls for a second extension of Line 11 to be built towards . The target opening date is 2030, but might be pushed back. Should the second extension be built, Line 11 will eventually be fully automated. Automatic train operation is not currently planned for the Rosny extension, although the RATP and STIF had considered the possibility of adding it later on.
Rolling stock
As of March 2013, it was expected that additional MP 14 stock will be used for line 11. Unlike lines 14 and 4, these MP 14's will be manually driven and will replace the MP 59. As of October 2022, the trains are currently in test at the Rosny extension. Passenger service started in June 2023.
Line 14 extension
Northern extension of line 14
The automated Line 14 was extended north from to Mairie de Saint-Ouen, with the primary aim of reducing overcrowding on line 13. The adopted solution connects both branches of line 13 to line 14, with stations at on the Asnières – Gennevilliers branch and on the Saint-Denis branch. An additional station connects with the RER C station, and another with the Transilien Paris – Saint-Lazare lines at Pont-Cardinet, and the final one with the RER D at Saint-Denis Pleyel. Construction on the extension began in 2014, with an aim of completion by 2019. Completion was later pushed back to 2020 after flooding from the water table stopped the tunnel works for a year. The covid-19 pandemic then further delayed the opening to December 2020. As of spring 2023, the current estimate for the opening of the extension is mid-2024 -- just before the Olympics.
Southern extension of line 14
Line 14 is also being extended south from Olympiades towards Orly Airport. The extension will travel southeastward from to , with a possible connection to Line 7's Villejuif branch, with a planned opening in 2024 (promptly before the 2024 Summer Olympics in Paris).
When both extensions are complete, it is expected that Line 14 will eventually be merged into the proposed Grand Paris Express system.
Rolling stock
In February 2012 the STIF announced that with the two extensions planned, the brand new MP 14 class of rolling stock will replace the MP 89CA and MP 05 stock on Line 14 starting from 2020. This new stock would be in eight-car train formations, something not yet employed on the Paris Métro but allowed by the length of all Line 14 stations. The current MP 89CA and MP 05 stock would then be reassigned to line 4, alongside some 6-car MP 14s. They will replace the manually driven MP 89 CC rolling stock, which will be refurbished before going to line 6 to replace the aging MP 73 rolling stock.