Nearly 4 billion euros in construction projects, the Île-de-France network undergoing work from June to August: summer 2026 is shaping up to be one of the most disruptive in years for getting around Paris. RER B, RER C, Metro Line 4, Gare du Nord and Gare de Lyon stations: several key routes will close during peak tourist season and business travel.
For a business, a hotel, or a business traveler, the stakes are not theoretical — a delayed meeting or a missed flight can be costly. Here, with supporting dates, is what's closing, when, and concrete alternatives to stay mobile during Paris transport works this summer 2026.
Key Information
- RER B : the central section — the direct route to Paris-Charles-de-Gaulle airport — will be closed from July 25 to August 16, 2026.
- RER C, Metro Line 4 and Gare du Nord / Gare de Lyon stations (Operation "Double Whammy") will also be interrupted between July and August, as part of nearly €4 billion in works coordinated by Île-de-France Mobilités.
- For professionals, there's one watchword: anticipate. Private door-to-door transfers, corporate shuttles, and chauffeur services ensure secure airport journeys and tight-scheduled appointments.
Summer 2026 Works in Île-de-France: What's Closing and When
Every year, summer is the preferred window for modernizing a network that is saturated the rest of the year. In 2026, the effort is exceptional: Île-de-France Mobilités announced nearly 4 billion euros invested throughout the year, with a major portion concentrated during the summer period. The objective: to renew tracks, switches, and signaling, and to prepare for the arrival of new trains and the extension of the network (Grand Paris Express).
The immediate consequence for travelers is that several lines will partially close, some during the peak of August.
RER B: Airport link closed from July 25 to August 16
This is the most critical closure. The central section of the RER B will be interrupted for 23 days, in two phases: no trains between Gare du Nord and Bourg-la-Reine from July 25 to August 7, then the interruption extended to La Croix de Berny and Robinson from August 8 to 16.
These works are preparing for the modernization of signaling (NExTEO project) and the arrival of future MI20 trains. Direct consequence: the direct rail link to Paris-Charles-de-Gaulle airport will be severed in the middle of the summer season.
RER C: Paris-Austerlitz cut off from the west from July 15 to August 22
The RER C line will be suspended between Paris-Austerlitz and the western Île-de-France region for 39 days, from July 15 to August 22, 2026, for a major safety and modernization project. This affects connections to Issy, Versailles Rive Gauche, Saint-Quentin-en-Yvelines, and Pontoise. This is one of the longest summer closures, impacting both commuter journeys and travel to business districts in western Paris.
Metro Line 4: Les Halles ↔ Montparnasse closed from July 6 to 24
Metro Line 4 will be interrupted between Les Halles and Montparnasse-Bienvenüe from July 6 to 24, 2026, due to infrastructure work. This heavily used north-south axis connects several major stations; its closure will shift traffic to already busy parallel lines, which should be anticipated for any journey to or from Montparnasse.
Gare du Nord and Gare de Lyon, Tramway: The "Double Whammy" Operation
From July 25 to August 16, the"Double Whammy" operation will impact the underground stations of Paris Gare du Nord and Paris Gare de Lyon: forty switches will be renewed, and tracks will be replaced.
Throughout this period, there will be no direct RER connection between Gare du Nord and Gare de Lyon, and significant congestion is expected on Metro Line 5. Additionally, Tramway T1 will be interrupted between Bobigny–Pablo Picasso and Noisy-le-Sec from June 1 to August 31. The table below summarizes the main closures.
What are the alternatives for getting around Paris this summer?
No single solution covers all scenarios. The best approach is to cross-reference the purpose of your trip (appointment, flight, client transport) with the day's constraints. Here are the options and their limitations.
- Replacement buses and parallel lines. Operators are increasing bus services and directing travelers to unaffected lines. This is free and clearly signposted, but comes with predictable congestion during peak hours and extended journey times: hardly compatible with a tight schedule.
- Cycling and walking. For short distances within the city, cycling remains unbeatable this summer. Its limitations are well-known: luggage, weather, professional attire, and distances to airports disqualify it for most business trips.
- Ride-hailing and private transfers. When there's a flight to catch or an unmissable appointment, a pre-booked door-to-door transfer remains the most reliable option: no connections, pickup at your address, and a guaranteed journey regardless of the rail network's status. This is precisely where the RER B closure changes the game for reaching Roissy.
Getting to the airport (CDG, Orly) during the works: the critical point
This is the summer's top issue. With the central section of the RER B closed from July 25 to August 16, direct rail access to Paris-Charles-de-Gaulle is severely disrupted during the peak summer travel season.
Public transport alternatives exist (direct buses, alternative routes), but they lengthen and make the journey more precarious — a real risk when traveling with luggage or a tight boarding schedule.
For business travel, the solution is simple: book an airport transfer in advance, with real-time flight tracking and built-in buffer time for delays. This removes the 'network' variable from the equation. Orly, less dependent on the RER B, remains more accessible, but is also experiencing traffic diversions: here again, anticipation is key.
Businesses and Hotels: Ensuring Mobility for Your Teams and Clients
For management, an office manager, or a hotel concierge, summer 2026 is more than just a logistical constraint: it's a matter of image and productivity. A stranded employee, a VIP client late for a transfer, and your service promise falters. The solution lies in three principles: anticipating critical journeys (airports, train stations, inter-site travel), centralizing bookings, and entrusting critical journeys to a provider who can guarantee punctuality.
This is the focus of the offer PREYA for professionals : airport and train station transfers with flight tracking, corporate shuttles and chauffeur services for up to twelve hours, centralized booking and invoicing, hybrid and electric fleet for carbon reporting. The network relies on over 1,000 partner drivers in France and 24/7 customer service — enough to absorb a summer demand peak without compromising quality. The goal is not to replace public transport, but to secure journeys where uncertainty is not an option.
Plan Ahead for Summer : airport transfers, team shuttles, or chauffeur services, ensure your company's mobility continuity during the works. Request your corporate offer or speak to a PREYA advisor.
Which transport lines are closing in Paris in summer 2026?
The main closures concern the RER B (central section, July 25–August 16), the RER C (Paris-Austerlitz westbound, July 15–August 22), Metro Line 4 (Les Halles–Montparnasse, July 6-24), Gare du Nord and Gare de Lyon (Operation "Coup Double", July 25–August 16), and Tram T1, as part of nearly €4 billion in works by Île-de-France Mobilités.
Will the RER B be closed this summer 2026? On what dates?
Yes. The central section of the RER B will be closed from July 25 to August 16, 2026, in two phases (Gare du Nord–Bourg-la-Reine, then extending to La Croix de Berny / Robinson). This closure severely disrupts direct rail access to Paris-Charles-de-Gaulle airport during the summer peak.
How to get to CDG airport during the summer 2026 works?
With the RER B line closed, alternatives include direct buses, taxis, or a pre-booked door-to-door private car service (VTC). For a tight flight schedule or a trip with luggage, a private transfer with flight tracking remains the most reliable option, as it doesn't depend on the state of the rail network.
What are the alternatives to RER C and Line 4 this summer?
For RER C and Line 4, rely on additional replacement buses and parallel lines for short journeys, cycling for trips within the city, and private car services (VTC) or private transfers for business trips and airport connections, where punctuality is crucial.
How can a company organize its teams' travel during the works?
By anticipating critical journeys and relying on a chauffeured transport provider offering centralized booking, corporate shuttles, dedicated vehicle services, and single invoicing — like PREYA's mobility continuity solution. This ensures punctuality and traceability, without mobilizing internal resources.
Summer 2026 will leave no room for improvisation when traveling in Paris. The good news: the dates are known, so they can be anticipated. Identify your critical journeys today — airports, train stations, client meetings — and secure them before the July works begin.
For journeys where delay is not an option, speak with a PREYA advisor.
Sources
- Île-de-France Mobilités — "Summer 2026 Works" communications
- SNCF Réseau — major 2026 works in Île-de-France
- RATP — summer works: metro, RER, tram
Data verified on June 3, 2026. Schedules and sections may be adjusted by operators: please re-verify at the source.
