Crossing Arizona on I-40 can be a real slog, but considering that Route 66 is roughly the same route provides options.
Not much in Holbrook but along the old 66 section is one of the last motels where all the rooms are concrete Tee-Pees. Used to be a chain of them, now mostly gone. Also a lot of petrified wood outlets.
Winslow has the Standing on the Corner park thats worth a stop. In the area are the Petrified Forest NP and Meteor Crater, a privately run park.
Flagstaff is good for food, lodging, and gas. Its also the access to the Grand Canyon but in a U-haul it would be a good two hours each way plus sightseeing time. Sedona and Oak Creek Canyon are to the south but I don't recommend the roads or traffic there for any kind of big rig.
The only Harley dealer you'll pass is in Beaumont, just west of Flagstaff at exit 185. The motel where Easy Rider was turned down is just past the dealership.
Not much at Williams although if you like trains there is a tourist train to the Grand Canyon that starts there. Supposedly there is a great cafe somewhere but don't know the name or where it is.
Nothing at Ash Fork.
Suggest catching old Hwy 66 at exit 139 and spending some time in Seligman. Fun to walk around, get an ice cream cone, shop in the tourist trap shops, and maybe get a haircut at Angel Delgadillo's shop. He's the guy who started the whole Route 66 fascination, originally to keep his town from dying after the interstate bypassed it.
Also suggest staying on 66 through Valentine, stopping at the store. Lot of motels and food places on 66 coming into Kingman.
If you are up to it and like curvy roads in a truck, take Rt 66 out of Kingman over Sitgreaves Pass to Oatman, an old mining town that was destined to die until the tourists discovered it. Descendants of the miners' burros roam the streets looking for handouts.
California is just down the hill and across the river.
I'm helping my in laws to move from VA to CA...
