I've had trailers, 5th wheels, motor homes, campers, and canopies. The tallest was my 5th wheel that was 13'4". The only problem I really had was wacking some tree limbs periodically, but if you go where big trucks travel, you generally don't have any. It's in RV parks and campgrounds that you find the low limbs. I did go to one campground and couldn't because entry was through a low train trestle, and once, in New York, I had to detour around an overpass that was too low. Other than that, no problem. The motor home I now have is 11'6" and I've had nothing to worry about for years.
Hope this helps. OH, I forgot to mention, even though it's obvious. You do have to count your airconditioner sticking up and your tires being fully inflated when measuring.