The Tunnel des Montets is also known as the Col des Montets Tunnel and by the rail operator as the Tunnel de Montroc. Primarily, this is a single track railway tunnel but, uniquely in France, it has dual use as a road tunnel. The tunnel was inaugurated on 1 November 1907, just six years after the railway reached Chamonix in July 1901.
The tunnel is 1883m long with an average altitude above sea level of 1386m the highest point on the Mont-Blanc Express route that runs between St.Gervais - Le Fayet (Haute-Savoie) though to Martigny in the Valais canton of Switzerland. Either side of the tunnel are the rail stations of Montroc-le-Planet (Chamonix side) and Le Buet (Valloricine side).
After an extensive refurbishment, the Tunnel des Montets re-opened in December 2014. When the Col des Montets it is a safe and interesting experience for motor vehicle drivers and their passengers to travel under the Col though the Tunnel des Montets.
Safety for drivers : Rules for passage through the Montroc Tunnel
- All vehicles are restricted to a maximum height of 2.5m and a maximum length of 5.5m. Where a vehicle that exceeds these parameters enter the tunnel, access to the tunnel by any other vehicle is prevented until the offending vehicle exits the tunnel
- The Speed Limit is 50 km/h. Despite the route improvement, it is imperative to respect the speed limit
- The distance between two vehicles should be at least 100m
- Vehicles must NOT stop or attempt to make a U-turn or to reverse inside the tunnel, except in cases of emergency or where directed to do so by a Gendarme or Pompier.
- If your vehicle breaks down and you cannot re-start it, or free-wheel it forward, do not exit the vehicle. The video surveillance system will have allowed someone to observe your situation and an emergency intervention will be dispatched. Wait in the car until they arrive. Try to park the vehicle close to the side wall. Where traveling from Montroc to Vallorcine (Monty right into Val) use the right wall. Where traveling from Vallorcine to Montroc (Val left Monty), park close to left wall. If Emergency vehicles are attempting to pass, cross the yellow line and park, Monty right into Val but Val left Monty.
- In the event of fire in the tunnel, the fire detection and suppression system will control the fire. Stay in your vehicle unless ordered to evacuate. If ordered to evacuate, you will be directed to either the Montroc or Le Buet exit. That exit might not be the closest exit. Follow the directions. Remember, the tunnel is 1883 metres long.
- If you have to exit the tunnel on foot, stay close to the tunnel wall. (Monty right into Val but Val left Monty) You might have to walk around parked cars. There cannot be more than 17 cars in the tunnel at any one time. On leaving the tunnel, do not walk away. Your vehicle will have been identified by the surveillance system and the Gendarmes will want to verify that you are safe. At Montroc, congregate at the Station. At Le Buet exit, do not congregate at the tunnel entrance and do not walk down the track toward Le Buet Station. This is an area of high avalanche risk. Walk quickly up the road and congregate at the Skiroc chalet.