The company Tmb-Geie, which manages the Mont Blanc road tunnel, has announced a complete closure of the tunnel for traffic from 5 pm September 4th to 10 pm December 18th, 2023.
This will be the first time that deep remediation work of this scale will have been carried out on the Mont Blanc tunnel structure since its construction 60 years ago.
Therefore, this work will be a test project to assess the feasibility and effectiveness of these remediation methods. A second test phase is planned for 2024.
The construction site in 2023 will be 600 meters long and will focus on restoring the vault of the tunnel in two sections.
The company specifies that “the implementation of these works will involve the dismantling of all safety systems on the vault – accelerators for controlling longitudinal air currents, cameras and automatic event detection, thermometric cable, etc – systems that represent one of the pillars on which the safety device is based. In the impossibility of removing them every evening and remounting them every morning, this site will require a total closure to traffic.”
The tunnel operator Tmb-Geie has published the following map of alternative routes vehicles should use during the closure:
Map by Tmb-Geie
In the spring of 2024, a further 640 metres of the vault will undergo remediation work, with the total cost for both the 2023 and 2024 projects being 50 million euros.
The work will mainly consist of a new waterproofing system, as the main factor of ageing is linked to water infiltration.
The management company has chosen autumn because it is the period of lowest traffic flow, especially for light vehicles (which in 2022 represented 67% of total traffic).
Photo credits @ Marc via CC BY-NC-ND 2.0