As of the December 2023 timetable change,[update] Chemins de fer du Jura (CJ) operates the following regional railway services: CJ also operates the following bus lines: The first company to open a line in the region was the Chemin de fer Tavannes-Tramelan, which opened the 1,000 mm (3 ft 3+3⁄8 in) gauge line linking the villages in its name in 1884.

[4] In 1927 the two companies merged to form the Chemin de fer Tavannes–Noirmont [fr].

[5] On 7 December 1892 the longest of the region's lines, the Chemin de fer Saignelégier-La Chaux-de-Fonds (SC) was opened linking the places in its title.

[6] The 25 km (15.5 mi) line ran from Saignelégier (Place d'Armes) to La Chaux-de-Fonds, the final kilometre being laid along the streets to the town centre.

The complete system was electrified, some 40 years after the first electric trains had run.