The rumble strip would have been my last guess on what outside noises would spook someone. There are all sorts of noises in the woods at night (not man made) that most people are not familiar with.
Rarely do I get spooked in the woods. Generally I keep a clean camp and stash my food out of the immediate area. Mostly black bear country. Never backpacked in griz/brown bear country. I’m pretty sure that I would be on edge and jumpy if I were in their territory.
I’ve even fallen hard asleep in crazy wind storms which are probably more dangerous (falling trees) than any critters I may come in contact with.
Usually I’m more concerned with doing something dumb and getting hurt or not being aware and getting lost.