Shelf roads are easy when your paying attention. There is (in most cases) more than enough room to dodge boulders and still keep all 4 wheels planted firmly on terra firma, at least in my expirience. That jeep trail in WY looks to be the exception. But when you start fiddling with stuff (camera, phone, navigation, food and beverage, ect) it takes just one moment of misplaced focus to make your day go sideways. I learned this back east in the trees. A loss of focus would only cost you a mirror or a body panel. Out here it can cost a life on the wrong road.