Île-de-France Mobilités and SNCF Réseau have entered the critical phase of their €2.2 billion summer engineering programme, with extensive closures on the RER B, C and D lines that funnel international travellers between Paris, its business districts and the country’s largest airports. The dedicated “Grands Travaux Été 2026” portal—updated on 27 July—confirms that from 25 July to 16 August services between Mitry-Claye / Aéroport CDG 2 and Gare du Nord will operate at just one train every seven minutes, while the central RER D trunk between Gare du Nord and Gare de Lyon is completely shut. The works involve the renewal of 26 sets of points at Gare du Nord, 14 at Gare de Lyon, and 1.5 km of track in the Saint-Denis sector, all prerequisites for the introduction of the new MI-NG double-deck rolling stock and the 2027 capacity uplift tied to the Paris Expo. Replacement bus services link affected suburban stations, but airport operators warn that journey times from the city centre to CDG can now exceed 90 minutes at peak. Corporate travel desks are urged to re-route staff to the non-stop “CDG Express” (still running) or book taxis with generous buffers. Airlines including Air France have temporarily relaxed minimum report times for connecting passengers arriving at Gare du Nord by metro or taxi. Hotels in Roissy report occupancy spikes as firms shift meetings closer to the airport. The disruption also affects daily commuters to the La Plaine business zone and the Stade de France; event organisers have arranged charter coaches for concerts and sports fixtures during the blackout. SNCF notes that heavy works were deliberately concentrated into a three-week window to avoid overlapping with the September launch of the Rugby European Cup season. A full resumption of normal RER service is scheduled for the first trains on Monday 17 August, but finishing works will continue overnight through October. Mobility managers should therefore keep contingency plans active into the autumn.
