For drivers, primarily, of course. But country roads in France are used too by tons of cyclists, both with and without motors. I've even found myself waiting to overtake cross-country skiers who train on roller skates during the summer months. But the basic breakdown is between people who use the roads to earn their living, and others who are driving along it for purely personal reasons, maybe to go on a shopping excursion, or maybe for pure fun, as tourists.
In my article of 3 November 2007 entitled Deadly collapse of rocks in Choranche [display], I described a freak accident on the mountain road through Choranche in which a huge rock rolled down from the top of the slopes and fell onto an automobile, killing a father and his son.
Everybody knows that the spectacular limestone valley of the Bourne, from the ski resort of Villard-de-Lans down to Pont-en-Royans, is fragile and therefore treacherous, and it is quite possible that more rocks will fall down onto vehicles using the road. The authorities are aware that, if they invite tourists to use such a road, known to be risky, they could be held responsible for future accidents. So, there has been talk about condemning this road, even though this would be a great pity from a touristic viewpoint.
Fortunately (one might say), this treacherous road is also used by many working people, in diverse fields: truck-drivers, local farmers, tradesmen, etc. They're aware of the constant dangers when driving along this road, but they're prepared to accept this risk. If they weren't, they would no longer be able to earn their living. For these professional users, it's entirely out of the question that the road might be closed permanently.
So,we're in a weird situation. It's almost as if the authorities are saying to people: Don't use this road unless you're really obliged to, for professional reasons. It's dangerous. So, don't say we didn't warn you. In fact, the authorities can't really express themselves explicily in this kind of language. So, they simply hope that the message will get spread around by word of mouth, and that people will react accordingly.