Île-de-France Mobilités will be spending €3.8 billion in 2026 to improve rail transport in the Ile-de-France region in conjunction with RATP, Transilien SNCF Voyageurs, SNCF Réseau and SNCF Gares & Connexions. In a press release, the organisation explains that " maintaining and modernising rail transport infrastructure is an absolute priority to guarantee reliability, safety and comfort for passengers using the Île-de-France network ". This investment, which will be matched by the Île-de-France Region and the French government, will involve the purchase of new trains, upgrading of lines and interconnections with the future metro lines 15, 16, 17 and 18 of the Greater Paris project.
A new metro for half of Paris's lines
In detail, the new-generation MF19 metro will be deployed on no fewer than 8 metro lines, including line 10, on which these modern Alstom trainsets are gradually being introduced. By 2027, lines 7, 7bis, 3bis and 13 will follow. This will entail modified timetables or regular interruptions to traffic in order to test this rolling stock. A second equipment campaign will then be carried out between now and 2034, covering lines 12, 8, 3 and 7. But from summer 2026, traffic will be particularly affected. Line 8 trains will not stop at République from 22 July 2026 until April 2027, as renovation work begins at this station in the centre of the capital.
As with the new trains on line 10, which has been extended to Rosny-Bois-Perrier in 2024, these new trains will offer more space for passengers and will be equipped with USB ports, a station announcement system and information screens. For RATP, they will also consume 20% less energy than current trains. Modernisation work is also planned on lines 4 (closed from 20 April to 1 May between Château Rouge and Châtelet) and 12, as well as work on line 13 to prepare for its automation, scheduled for 2032. Considered to be one of the worst lines on the network, it will then be the 4th busiest in France.th to be automated after lines 1, 14 and 4.
RER lines not spared
In the first half of 2026, RER passengers will also be affected by these major works aimed at improving mobility in the Ile-de-France region. These include the renovation of Nation station on the RER A line (where trains will not stop from 29 June to 30 August 2026), the renewal of points on the RER B and D networks, and safety work and the replacement of catenary wires on the RER C line. These works, which will also have an impact on train traffic on certain weekends in spring and during the summer of 2026, should also prepare the way for the deployment of new rolling stock on lines B, D and E. This change will be accompanied by the launch of Nexteo, a high-performance operating tool that will improve the management of RER B and D traffic, particularly at peak times, in order to reduce the intervals between trains. Replacement buses will be introduced on these different lines during periods of service disruption, in the evenings, at weekends and during the summer of 2026.
