The cars used by staff at over a dozen stations will be now be available for rent on OuiCar, a web platform for private car owners to rent out their own vehicles that SNCF invested into in 2015.
"The cars were being used by SNCF staff primarily during the work week, travellers can rent them at the weekend at very affordable rates," said SNCF and OuiCar.
The stations include popular tourist destinations such as Bordeaux, as well as Brest and Vannes in Brittany.
Famous for its TGV high-speed trains, SNCF has sought to move beyond the rails and to provide a variety of "mobility" solutions to people. In addition to OuiCar, it has a car-sharing service and runs a low-cost intercity bus operation.