The Mont-Blanc tunnel will close for fifteen weeks in 2023 and then in 2024

There “durability” of the Mont-Blanc tunnel is at stake. The major road axis between France and Italy will be closed for more than three consecutive months, from September 4 to December 18, 2023, then as much again in 2024, for renovation work. They will continue in the following years. Spot repairs on this 11.6 km stretch are no longer enough. “We made the choice to carry out more important, more substantial work to give a second life to this tunnel”explained Grégory Schwarshaupt, deputy director of the French concession company Autoroutes et Tunnel du Mont-Blanc (ATMB).

The long periods of closure will constitute a “first” for the tunnel since it reopened in 2002 after the fire which ravaged it on March 24, 1999 and caused the death of 39 people. On each side of the Alps, this closure worries. In Italy, some fear that it will “kneel down” the country’s economy. In France, elected officials fear a risk of increased pollution in the Maurienne valley, where traffic could be transferred, via the Fréjus tunnel, another important Franco-Italian axis.

Little margin between the Ultra-Trail and the Christmas holidays

The Mont-Blanc tunnel sees around 1,700 heavy goods vehicles pass through per day, while light vehicle traffic averages 3,600 cars/day, with peaks of over 6,000 in August and troughs in autumn. The first two construction phases, described as “experimental”must allow the repair of the vault on four sections totaling 1,200 meters, or about 10% of the total length, and to develop the most efficient schedule possible for the remaining 90%, which will also have to be renovated in the course of the following years.

The closure will take effect on September 4, 2023, the day after the end of the Ultra-trail du Mont-Blanc (UTMB) events. It is due to end on December 18, shortly before the Christmas holidays. “We don’t have a lot of room” between these two appointments, admits the deputy director. The first test site will allow the renovation of 600 meters of vault in two places. If its results are positive, an additional 600 meters will be renovated in 2024. These first two phases have been budgeted at 50 million euros, supported equally by the French (ATMB) and Italian (SITMB) concession companies.