The RER B train is expected to go under track renovation on a number of weeknights and weekends this Spring. There will be replacement bus services from Aulnay to CDG and the RER B will depart from ground level platforms at Gare du Nord on certain weekends.
If you don’t want to go through this bus hassle, then hop on other transportation options, such as the CDG Bus from Opera Garnier. Remember there is a fixed flat rate to the airport on regular taxis, which is around 60 euros. The 2€50 RER B + Bus option is obviously much more economical, particularly now that regular RER B price to CDG is 13€.
So on which days should you be allowing more time to the airport. Here is the full list.
WEEKNIGHTS: Service is suspended shortly after 10pm, until end of April, except most weekends.
WEEKENDS: All day on March 29 (trains go to the airport, but fewer and from the upper platforms at Gare du Nord). Not train at all all day on April 19, 20, 21, May 3 and May 4.
You can also use RER D to Goussainville and use a bus or Uber/Bolt/Heetch to reach the nearby airport.
If you head to the Orly Airport on line 14, you will also face closures on most nights after 10pm, and all day on April 5 & 6, May 30 & 31, June 15 & 29, and August 4 to 8.