The trains on this line travel between Gare Montparnasse in Paris and the west of Île-de-France region, with termini in Rambouillet, Dreux and Mantes-la-Jolie on a total of 117 km (75 mi).

Former rolling stock include SNCF Class Z 5300, which only ran on sections electrified with 1500 V direct current, SNCF Class BB 27300 and BB 7600 [fr] (SNCF Class BB 7200 modified, since 2012, also only on sections electrified with 1500 V direct current) with voiture de banlieue à 2 niveaux coaches, which are currently being withdrawn alongside Z 8800 material.

This line, according to SNCF, will travel from start to the terminus in 1 hour, and operates as per this route, on the Paris–Brest railway: This line is electrified using a 1500 V direct current.

This line according to SNCF will get from start to terminus in 1hr, and operates as per this route, on the Paris–Brest railway up to Saint-Cyr, then on the ligne de Saint-Cyr à Surdon [fr]: This line is electrified using a 1500 V direct current between the Montparnasse station and the Plaisir-Grignon station, and a 25000 V alternating current elsewhere.

Taking GEPU (which is for a train that runs express between Paris-Montparnasse and Sèvres-Rive-Gauche then stops all stations to Plaisir-Grignon) as an example, the table describes how names of services are structured.