The planned reopening was confirmed by TMB-GEIE, the binational operator of the Italian-French tunnel, in an official statement issued on 11 December. According to the operator, traffic will resume after the final mandatory safety exercise planned for 2025, provided that all remaining system tests are successfully completed.
Final safety tests underway
TMB-GEIE said the reopening later today remains conditional on the successful completion of more than 800 functional tests of the tunnel’s safety systems. These include automatic incident detection, ventilation and airflow control, cameras, temperature monitoring cables and lighting.
Many of these systems were dismantled in the work zones and later reinstalled and reconnected to the tunnel’s central supervision system, LOGOS, which continuously analyses around 36,000 data points from 12,000 pieces of equipment.
Testing began at the end of November and is still ongoing this morning, involving technical and safety teams on both the French and Italian sides.
Renovation works nearing completion
The tunnel was closed on 1 September 2025 to allow the second experimental phase of the tunnel vault’s rehabilitation. The works ran 24 hours a day for 102 consecutive days, involving more than 150 workers and accounting for over 150,000 working hours, according to the operator.
The project focused on two sections of the tunnel identified as representative of different geological and structural conditions. It included demolition and reinforcement of the vault, water ingress treatment, full sealing of the structure, and the installation of 220 prefabricated reinforced concrete shell elements.
The total investment for the 2025 works amounts to €21 million, funded jointly by the two concession holders: ATMB (France) and SITMB (Italy).
Seasonal restrictions remain in place
Hauliers and drivers approaching the Mont Blanc Tunnel should note that seasonal traffic measures remain in force in the region.
From 1 November to 31 March, the speed limit is reduced from 130 km/h to 110 km/h on the A40 and A411 motorways between Vallard and Le Fayet, under the Arve Valley Air Protection Plan (PPA2).
In addition, winter equipment is mandatory in Haute-Savoie during this period. Vehicles must be fitted with winter tyres or carry snow chains or snow socks to reduce accident risks and avoid road closures during heavy snowfall.
Reopening subject to final confirmation
TMB-GEIE stressed that while the reopening is planned for 5:00 pm today, it remains subject to the successful outcome of the final safety system tests and the last scheduled safety exercise.
If confirmed, the reopening will restore one of Europe’s most important Alpine freight corridors just ahead of the peak winter transport period.
