The link allows through running between the main Swiss rail network and the until then isolated line east of Annemasse in Haute-Savoie, which was served until 2013 by French SNCF services.

Track already existed as far as Stade de Genève station;[2] the full route opened on 15 December 2019 to Léman Express and RegioExpress services.

This was never realised due to competition from the Vaud canton which succeeded in keeping the Dijon – Vallorbe – Lausanne – St Maurice route as the main Simplon line to Italy.

To simplify electrification situation in the Geneva area, the portion between Genève-Cornavin and Bellegarde was changed from 1500 V DC to 25 kV 50 Hz AC in summer 2014.

Since completion, a continuous railway route runs from Cornavin station via La Praille, Bachet-de-Pesay, over the river Arve, in tunnel under the commune of Champel and on past Eaux-Vives, underground to Annemasse, as a financing for the French part of the new infrastructure was found.