Interstates safer than "Blue Highways?"TRIP UPDATE

Clearance is more likely to an issue on non-freeway roads, especially in 'older' parts of the country. Modern RVs are wider and taller than most trucks in the pre-interstate years.

I've seen questions about railway underpass clearance on US20 in upstate New York. I've even seen that kind of question for a town in west Texas.

So if your rig is big, and you want to travel off the main-grid, you want to invest in some sort of trucker's atlas or clearance database.