The Mont-Blanc Tunnel will be closed from next week until the middle of December.
The closure is to allow for major renovation – there will be further closures next year.
The company says it has deliberately chosen this time of year as tunnel usage is the lowest.
The autoroute heading to the tunnel will also be closed to allow for work to be carried out.
The tunnel carries 5,000 cars a day at peak times and was first opened in 1959.
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This winter was significantly warmer than average
