The Mont Blanc tunnel is open 24 hours a day all year long.
To allow maintenance work, there will be a contraflow.
The contraflow will be set as follows :
Alternating one-way traffic :
from October 5 to 8, and from October 12 to 15, from 10.30 p.m. to 6 a.m.
Possible inconvenience from 9 pm to 10 pm and from 6 am to 7 am due to the transit of any vehicles under escort.