Running north–south, the Southern branch line would help connect Germany, the north of Switzerland, and eastern France on the one hand with the valleys of the Saône, Rhône, the Mediterranean arc and finally Catalonia on the other.

The east–west Eastern and Western branches lines would help connect on the one hand London, Brussels, Lille and Île-de-France (i.e., Paris and surroundings) with Burgundy, Franche-Comté, south Alsace, southern Baden, and Switzerland on the other.

The first phase of the eastern branch runs 140 km (87 mi) of the 190 km (120 mi) planned length, connecting Villers-les-Pots (east of Dijon) to Petit-Croix (southeast of Belfort), was officially opened by President Nicolas Sarkozy on 8 September 2011,[2] with passenger services starting on 11 December 2011.

[2] Preparatory works began in 2005, and construction officially started on 3 July 2006 with a ceremony in Les Magny, Haute-Saône.

Réseau Ferré de France appointed French engineering and consulting companies Setec and Egis to build the line.