
First ever weekday closure of the RER B North axis in Paris
On Saturday 12 to Monday 14 August 2023, important modernisation work on the northern axis of the Paris train system RER B will result in a complete halt of traffic in both directions. SNCF Réseau. will carry out works between Gare du Nord and Mitry-Claye, and the closure is expected to have a large impact on Paris traffic as passengers from one of Europe’s busiest line must be moved elsewhere.
This operation is crucial to the smooth running of the Charles de Gaulle Express project, a planned railway line between Gare de l’Est in Paris and Charles de Gaulle Airport to alleviate the busy RER B line. The closure will make it possible to establish a temporary terminus for RER B at La Plaine Stade de France station, in order to maintain train services in the event of interruptions on certain sections of the line and to prepare for the arrival of the CDG Express shuttle.
According to SNCF Réseau, “These two temporary terminuses will increase the capacity for turning trains around on the north side of RER B and thus maintain train services in the event of traffic disruption on certain sections of the line. They will eventually interconnect with metro lines 15 (La Plaine – Stade-de-France), 16 and 17 (Le Bourget).” “Combined with the arrival of line 15 of the Grand Paris Express, these new turning lanes will be key to improving the quality of service on line B of the RER, one of the busiest lines in Europe”, explains Marc Guillaume, Prefect of the Île-de-France region and Prefect of Paris.
Transport substitutions
In summer, train use traditionally falls by an average of 30 per cent, but this is not necessarily the case on RER line B, the second busiest line in the Île-de-France region with over a million passengers a day. Every weekday, no fewer than 200,000 passengers use line B, with a peak during the morning rush hour, when 50,000 people travel (in both directions combined).

According to Île-de-France Mobilités, it will be impossible to transport all of the RER B’s regular passengers by road, despite maximum mobilisation and the introduction of replacement buses during the three days of closure. This is also the first time that work of this type – and closure of the RER B – will take place on a weekday. The region is therefore recommending that companies put in place measures to ensure that employees do not need to take public transport on Monday 14 August, such as encouraging working from home.
For travellers who are unable to postpone their journeys between 12 and 14 August, a special scheme will be put in place to increase the number of regular and alternative transport services. More than 600 buses on four routes (B2, B3, B4, B5) will serve the stations that will be closed for the period. Regular bus routes will also be reinforced. Finally, car-pooling will be free for all residents of the Île-de-France region.
Other impacts on traffic
On Saturday 12, Sunday 13 and Monday 14 August 2023, no trains will run between Paris Gare du Nord and Mitry-Claye on line K. Trains will run between Mitry-Claye and Crépy-en-Valois. TER traffic on the Paris-Laon line will also be affected. From 29 May to 27 August, trains will not stop at Bagneux station in either direction. From 22 July to 25 August, the RER line B will be closed between Bourg-la-Reine and Robinson. The Fontaine-Michalon – Massy-Palaiseau section will be closed from 14 July to 20 August. For TGVs, additional closures are planned between Fontaine Michalon and Croix de Berny from 22 July to 4 August, extending the closure zone from Massy-Palaiseau to Croix de Berny.
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