It divides into two parts at Courtalain, one going westward to Le Mans (towards Brittany and Pays de la Loire), the second one going southwestward to Tours (and onward towards Nouvelle-Aquitaine).

The positive results of LGV Sud Est encouraged the French government to pursue the construction of additional high speed lines.

The line leaves Gare Montparnasse to cross Paris's southern suburbs, partly under the Coulée Verte.

The western branch is augmented by the LGV Bretagne-Pays de la Loire project, resulting in a reduction of 37 minutes between Paris and Rennes.

[4] The Southern branch is augmented by the LGV Sud Europe Atlantique project, resulting in a reduction of around 50 minutes to Tours and Bordeaux.