In many of the Western states, all occupants have to be belted into seats that are certified for use while travelling. In our MH, the four seats in the dinette are placarded "not for use when the vehcle is in motion". Both front seats have belts, the barrel chair forward of the house door has one (used by one of our Labs) and the jack-knife sofa has three, one of which is used by the other Lab.
Unfortunately, even the front seats are lap-only and they're tied to the seat frame. I don't think they'd be much use in a crash, as the restraint integrity is governed by the seat fore/aft adjustment mechanism, which I'm sure isn't strong enough for crash loads.
There was a report on one website of a Class A RV being pulled over and the cop wrote up the driver for not wearing his belt. The driver said "we only have lap belts in this vehicle. From down there at your seated level how the hell could you see whether I was wearing the belt?" The cop replied "I didn't need to see inside the vehicle. The belt was hanging out the driver's door."
Frank and Eileen
No longer RVers or FR owners