Not a good idea lol

It depends on how fast and how far you plan on going (Avoid underpasses). We see this routinely in the Quartzsite area when people are just driving to/from their BLM campsite to a dumping station in town. I guess they're trying to minimize the risks of falling off their roof for a few mile round trip.

This rig was driving from Quartzsite to Yuma. They were doing 55mph, Lots of people were impatient and passing being the speed limit is 65 mph and it was really busy so some close calls with vehicles coming the other way. I followed quite a ways back for about 20 miles until there was a safe passing lane. Luckily there was very little wind.

Can you say "yard sale"??!