Lots of roads like that in Britian as well and the speed limit is 60mph/100kph. Not uncommon for two cars on a single track road to adjust speed to pass each other at a passing place without slowing down much, so at a closing speed of over 100mph. Perfectly safe for human drivers who know the roads.
If you look at the accident maps, there are almost none on single track roads and lots on twin track roads. My hypothesis is that driving on a single track road feels much more risky so people pay more attention and slow down more on blind corners. Also, it’s not possible to overtake and a lot of accidents are related to overtaking.
