Commuters who rely on the Saint-Jérôme, Candiac and Vaudreuil-Hudson AMT train lines will have to find other routes in to and out of the city today.
The three lines are shut down for maintenance work.
Crews are updating the signalling system, extending one of the south-bound tracks and expanding the platform at Vendome station.
There are no express buses running as a replacement to the trains and commuters will have to make alternate plans on local transit.
The service interruption will continue tomorrow on the Vaudreuil-Hudson line, but special bus service will be offered. All other trains will be on the holiday schedule.