France-Italy Mont Blanc tunnel to close for over three months from September
Drivers must take alternative route through other Alpine passes or tunnels
The tunnel was closed at the same time last year
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The Mont Blanc tunnel is to close to all traffic for three months later this year as important work is carried out.
The tunnel will close in both directions between September 1 and December 12, 2025 to freight and regular traffic, the tunnel’s management announced yesterday.
“Autumn is considered to be the period with the least impact on tourism,” said the réseau d'Autoroutes et Tunnel du Mont-Blanc (ATMB) that manages the tunnel.
The dates were agreed with local authorities on the French and Italian sides of the tunnel.
Two main alternative routes
While the work – tests on the replacement of the tunnel’s vault – take place, drivers heading between France and Italy through the mountains will need to take alternative routes.
The two common alternatives are the Fréjus tunnel to the south, or the Grand-Saint-Bernard tunnel to the north and east.
Other smaller mountain passes can also be used, but risk closure during periods of snowfall.
“It is estimated that around 90% of HGVs will be heading for the Fréjus Tunnel, while light vehicles will be split depending on their origin and location,” the ATMB said.
The majority of traffic passing through the tunnel, around 75%, is light vehicles such as family cars and motorcycles.
The route was similarly closed for a 15-week period at the same time last year, as initial work on repairing the tunnel vaults took place.
Any deviation from the scheduled closures will be available on the tunnel’s website, via the interactive calendar at the bottom of the page.
