We always used the couch and also the dinette seat belts in our RV s. If someone needs the bathroom, I will allow it if I am on a secondary road, but on a highway, we always stop for a break. Same with snacks.
Once when driving, they went to grab a soda, and a casserole came flying out of the refrigerator!
The beagle had a field day with that lasagna!!
Also, aunt Patty once hit the can, and later, bumped her head, with a false sense of security, not realizing how much motion was in the coach.
So now, it's always safety first!!