Overview

• The Mont Blanc tunnel, a critical link between Courmayeur, Italy, and Chamonix, France, will close from September 1 to December 12, 2025, for maintenance work.
• This second test phase will repair two sections of the tunnel vault, covering a total of 254 meters, following a similar closure in 2024.
• Geie-Tmb, in coordination with Italian and French authorities, selected the autumn period to reduce impacts on tourism and regional economies.
• Alternative routes during the closure include the Great St Bernard tunnel, Little St Bernard pass, and the Fréjus tunnel from Bardonecchia.
• The results from this phase will inform the strategy for the tunnel's long-term restoration and operational safety.