Two priority sections for a line serving Provence and Côte d'Azur have been identified. The first involves the construction of an underground line in Marseille with platforms beneath St Charles station, plus a fourth track between Marseille and Aubagne to the east. This would relieve congestion in Marseille and double the capacity of the regional rail network.

The second scheme entails the construction of a line from a planned station at Nice Airport to join the Nice - Grasse line. The objective is to provide a TER loop serving the west of the Alpes-Maritimes area, allowing improved regional services particularly for the Sophia-Antipolis technology park between Antibes and Nice and to Monaco and Ventimiglia on the Italian border.