But those are dirt roads, which are not the same thing as a proper, old-fashioned gravel Macadam road. They can be excellent, and are pretty easy to maintain --- if potholes develop, fill them promptly with the right grade of gravel --- but don't do high speed traffic well. (Gravel is flung up by the wheels, which was why they started gluing it down with tar --- hence tarmac, or tarmacadam.)
Can find a good video of a grader in action, so here's a bad one:
