The Mairie des Lilas stop will also be inaccessible from June 26th, so line 11 line will end at Porte des Lilas until August 29th. Frequent work is planned on RER B, which will affect journeys between the city centre and Charles de Gaulle and orly airports. Services between Charles de Gaulle terminals 1 and 2 will also be suspended on July 3rd and 4th. Improvements take place during the summer, when public transport is less crowded. The RER C will also see its share of engineering works, with no trains running between Pontoise and Avenue Henri Martin on weekdays after 9:30pm, from July 1st until July 13th.

Source: The Local June 23, 2021 11:36 UTC