2,000 tonnes of salt already distributed between Sète and Nîmes: on the A9, the men in yellow are preparing for the snow

Salt spreaders ready to work from October 15 to March 15. Midi Libre – SYLVIE CAMBON

Hundreds of tons of salt are stored along the highway route. Midi Libre – SYLVIE CAMBON

Trucks ready to respond in less than an hour if necessary. Midi Libre – SYLVIE CAMBON

To react as quickly as possible to the next meteorological event, a whole system is put in place during the winter to prevent chaos from setting in on this axis which crosses our region, and on which the situation can degenerate quickly, as in February 2018 around Montpellier.
 

"Even though we are in the South, we have to deal with ice several times in the winter”, recalled Christophe Stanzione on December 22, deputy head at Vinci Autoroute of the L&#39 district. ;Hérault, in Sète, where several men in yellow gathered that morning, during a "snow school" suitable for the A9 motorway. Because even if the weather is still breaking records for mildness at the end of the year, winter is here, with the always feared risk of a strong episode that could disrupt the traffic on this major regional axis, or even blocking it for more than a day, as in February 2018.

15 to 20 tons of salt per snowfall

"Here, we are classified in zone E0, we must be able to cope with falls of 2 cm of snow per hour not exceeding 5 cm on the event. All the material is already ready and revised. Since October 15, the winter system has been operational over the 85 kilometers of this sector which runs from Vidourle to Agde, with the A 709 at Montpellier, and which goes merge on January 1 with that of Nîmes, to constitute a single Languedoc entity of Remoulins and Arles up to Agde.

"Between Sète and Nîmes, we have 2000 tonnes of salt already stored on the route" specifies the Vinci Autoroutes framework. "It is rare that an episode impacts the entire sector. In general, this requires between 15 and 20 tonnes, spread over several trucks."

Water and salt to prevent the formation of ice. Midi Libre – SYLVIE CAMBON

35 trucks can be mobilized in two hours

Salt is the primary weapon in the fight against the consequences of the cold on the highway. "By putting salt on the road, we cool it but we also lower it to -21° the freezing point, where water turns into ice" he explains: we can thus prevent the appearance of ice, and help the snow to melt in the event of a fall. In the sector, Vinci can mobilize 35 trucks in two hours , between its own means and agreements with external companies: salt spreaders, to spread salt (12 grams per m2) and  brine, dosed at 23 °, so that it sticks well to the roadway.

Precision dusting, with 12 g of salt per m2. Midi Libre – SYLVIE CAMBON

The eyes of the patrollers

"Whether we are in preventive or curative treatment, the ideal is to intervene as close as possible to the event and at the best time, with the best information' quot; insists Christophe Stanzione. "We have a whole network of around twenty weather stations along the sector, but also forecasters. We also rely on the patrol officers, who are the eyes of the highway: they know its route perfectly. Here, we have a cold spot at Fabrègues, and another with more humidity in Florensac. We also know that under a work of art, we have more cold, that everything that is metallic sets faster than the rest. We see the panels and slides whitening first and we know that with a clear sky the temperatures will be lower."

Vinci also enters into agreements with external companies to deal with a possible snow peak. Midi Libre – SYLVIE CAMBON

Clear at least two lanes of traffic

If, despite everything, ice appears, "You have to scrape it with a steel blade, then put brine on top. We use the Teflon blade for wet snow, the steel one for compacted snow. The snow removal strategy is to keep two lanes of traffic clear, the right lane and the middle lane." With contractual deadlines and performance obligations: "We must ensure a return to normal four hours after the end of a snowy episode, and in the event of icy conditions, we have two hours after the end' 39;alert to process."

The specter of February 2018

The fact remains that these systems can also be completely overwhelmed, like on February 27, 2018, where because of snow, although forecast, hundreds of motorists remained stuck in their cars all night near Montpellier.

"We can be surprised by an exceptional event, like freezing rain two years ago, or snow in 2018" recognizes Laury Segalou, the head of the Hérault district. "Users here are not trained to ride on snow. If a heavy goods vehicle gets in the way, like in 2018, it blocks everything, including our salting and snow removal circuits: our trucks are also stuck in traffic jams and can no longer act." Hence the necessary compliance with safety instructions in the event of snowfall, and in particular the ban on overtaking intervention vehicles in action, in order to avoid a possible nightmare scenario, before the return of sunny days.

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