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.
Col de Montets Tunnel MAJOR WORKS 2012-14 Renovation & Improvements
During 2 years from 2012 to 2014 the tunnel was extensively renovated and retrofitted for an enhanced functionality and usability, for both railway and road traffic.
Work carried out in the Col des Montets Tunnel:
- Railway upgrade and maintenance. The railway line was lifted and discarded. New track has been embedded into a new pavement, much like an urban tram system. The 800KW third rail is sunk into the pavement and isolated (turned off) when vehicles access the tunnel.
- Removal of the east side elevated side track, so that road vehicles now use a part of the same space as the train, with a 4m wide route marked by parallel yellow lines
- Strengthening and waterproofing the roof and walls of the tunnel, so that the tunnel remains dry with no water ingress or buildup of ice.
- Installation of overhead and side-wall lighting, video surveillance equipment, a new automated road traffic management system that regulates access to the tunnel and separates vehicles by 100m, an electric fire detection system and mechanical fire suppression system, road control points and specific equipment for a dedicated rescue team...
- New signage. Every 100m a sign on the wall indicates the distance to each exit
In March 2014, the average daily transit of traffic through the tunnel was 210 vehicles each way, during the day time and 24 vehicles each way, during the night. As confidence in the refurbished tunnel and the significant improvements to safety are learned by more people, it is expected that traffic volumes shall rise, as non-essential road users might take the journey to access ski services in the Vallorcine.
The Tunnel de Montroc has always been dual use, originally to allow people to walk from Argentière to Vallorcine when the Col des Montets was closed by avalanche debris or the risk of avalanche. Inside the tunnel, a 2.5m wide and 70 cm high, raised sidewalk on the east side of the tunnel, to the right of the track (when entering from Montroc) was just wide enough for a cart pulled by a horse; so when mechanised vehicles arrived, the progression to dual mechanised road and rail was a natural step. In the 1970s a traffic light system was installed to regulate the flow of vehicles through the tunnel. Even though a car could carefully navigate the narrow and elevated sideroad through the tunnel in about 4 minutes, the traffic light interval was set at 30 minutes! This led to frustration and disregard for the traffic lights, which led to confrontations and an unacceptable risk of collision. The 1990s saw the beginnings of the rapid second coming of Chamonix as a popular mountain resort. Whenever the Col des Montets was closed to avalanche, the traffic volume pressure on the tunnel intensified. Vehicle queues could tail through Montroc and back down the hill towards Argentière, with delays of over 2 hours at busy times.
Where the Col des Montets is closed, access to the French commune of Vallorcine with settlements from Le Buet down to the boarder with Switzerland at Chatelard is via the Tunnel de Montets. An avalanche descending into Vallorcine (the Valley of Bears) might require an extensive emergency response. Though the tunnel had no part to play in the aftermath of the Montroc avalanche of February 1999, the avalanche did emphasize the difficulties of disaster management for remote settlements. The close proximity of the tunnel to the avalanche and importance of the Montroc Tunnel as a lifeline for communities in Vallorcine placed a clear responsibility on the authorities to upgrade the tunnel.
After the Mont Blanc tunnel fire of March 1999 all road tunnels in France underwent a safety review. It was generally understood that the Tunnel de Montets would never comply with the new safety standards for road tunnels. However, as the tunnel is primarily a rail tunnel, the new safety standards were never applied. The tunnel continued to operate with no lighting of any type, no ventilation, no passing points, no escape routes or secure havens and no barrier between rail and road.
In 2001, a much improved traffic light system was installed. After testing over the first winter, the interval was reduced to 15 minutes, with a maximum of 22 vehicles in a single convoy.