I'm guessing areas that have more gravel/dirt roads have more graders but here in Central NY where gravel/dirt roads are very rare I have never seen a grader used for plowing snow. Heck can't recall seeing a V-plow in active use. Many Highway departments around here have them sitting out front on display with the town's name on them so they were used in the past!
Here in Minnesota the snow plows, mostly trucks run 24 hours a day as soon as we get a 1/4" of snow. Less if its on a Sunday.(Double time). It is a rare occasion when the snow accumulates enough to need a grader, much less a V-Plow. Normally snow never gets over 2" deep on the highways because of all the plow trucks. Only about once every ten years in the worst blizzards the trucks get called in for a few hours but are always out again by 5 AM. In fairness if the highway patrol calls them they have to go. First idiot that slides in the ditch seems to auto dial the patrolmans phone to the maintenance folks. A friend of mine that is a supervisor for the highway department has to have a guy out driving all night testing the roads when ever snow is predicted. Our tax dollars at work dumbing down the population even more.
Although progress is being made,,,,, we are decades away from autonomous vehicles dominating the roadways. It appears that for the autonomous vehicle to be 100% effective every vehicle on the road must be autonomous. This gives it the ability to analyze conditions and situations by data it gathers from all others in it's vicinity. This data gathering is critical for it to avoid accidents, stalled vehicles, etc. Don't think we'll see it in my lifetime.Going to be interesting to see how an autonomous 2wd vehicle handles deep snow with ice/packed snow under it. Will it know when to turn around and head home like a few humans do??
Mike