Having driven that route for a couple of decades in a variety of vehicles, fivers or MH, I do have a couple of comments. It is a good road. It is easily navigated. Not much shoulder.
The main problem is slow moving vehicles, drivers pulling out in front of you, dogs, goats, cows, horses, etc. on the road and sometimes broken down vehicles. Keep your wits about you. Don't drive through there after dark. Most of all be aware of drunk drivers.
This is posted by a white man who has had his hair washed and given a name by the Hopi people. Enjoy one of the most beautiful and sacred places in this country.