on the highway, on the way home from work. Not an RV; it was an enclosed white-box utility trailer, probably about 20 feet or so. big enough for 2 axles, anyway. It was wagging back and forth across the lane...I just thought "Yikes!!"
and pulled all the way over to the left lane, and passed as quickly as possible.
the guy wasn't even going fast. I couldn't see any wd or sway control..couldn't look. but I did see the "F-250" badge on the fender of the truck as I went past. So it wasn't undersized...AND it wasn't particularly windy. Trailer looked like it was quite possibly overloaded, though, from the way it was flexing. Anyway...skeery sight.