Lyon–Turin base tunnel: 20.5 of 115km of tunnel bores completed

The cross-border base tunnel (Mont d'Ambin/Mont Cenis) between the French Maurienne Valley and the Italian Susa Valley, with two 57.5 km tubes, ranks among the world's longest rail tunnels; as of April 2026 about 20.5 of the total 115 km of tunnel bores had been excavated. As of mid-2025 the cross-border section's completion was expected in 2033 (the source list had cited 2030). The full approx. 270 km new Lyon–Turin line is designed for freight trains up to 100 km/h and passenger trains up to 220 km/h. Merged (06.10.2026): the entry b2621554 on the same tunnel, initially recorded separately, has been merged into this one. It added that the tunnel system, including access galleries and cross-passages, totals around 164 km, that the main tunnel runs from Saint-Jean-de-Maurienne to Bruzolo in the Susa Valley and that about 11.5 of the 115 km of main bores had been excavated by the end of 2024; the overall Lyon–Turin project is estimated at around €26bn, up to 40% of it funded by the EU.