The Haut-Bugey line (French: Ligne du Haut-Bugey) (also nicknamed Lignes des Carpates) is a railway line in France. It is 65 kilometres in length and connects Bourg-en-Bresse with Bellegarde, travelling through the Jura Mountains. For a century and a quarter after its opening in 1877, it was a local line only, and with steep grades, tight curves, and a long poorly ventilated tunnel, it was a challenging line to operate. It suffered a gradual decline, until in 2006 it had a new lease of life as its renovation was chosen as the most cost-effective way to shorten the journey time from Paris to Geneva. The line was closed in 2006 for complete reconstruction and electrification. The upgraded line was inaugurated on 2 December 2010 featuring 25 kV AC electrification, replacement of 18 level-crossings with bridges, avalanche protection and daylighting a tunnel. Today the line enables a faster link between the French TGV network and Geneva, giving a Paris to Geneva journey time of just over three hours (a saving of nearly 20 minutes compared to the old route via Amberieu and Culoz).