OK Here,
Let's just open here with the facts.
Only about half of the drivers in vehicle/vehicle crashes are at fault.
A loose body can be a very large projectile in a crash situation.
It is rare that an incident is expected or can be anticipated.
To these ends, allowing passengers loose in a vehicle is a poor idea at best. The good news is that vehicle/vehicle accidents on free flowing highways are actually rare. So, if any time you are in any kind of traffic, all occupants should be restrained. That being the case, let's look at another case: Someone wants a something and you are on an open highway. With and only with the consent of the driver, someone unhooks and retrieves whatever and returns to the seat and hooks up again. With reasonable conditions and the short exposure time, I will accept this as a reasonable risk.
Then, there is the other part of travel by coach. Things to do that cannot be done in a passcar. These are things like playing board games and doing small safe crafts. As the view is better from most RVs, that is also a good thing to think about and this is particularly true if you are not on sceneryless interstate.
Now let's just look at vehicle to vehicle crashes involving RVs. (I never actually reported on these tests, but let's just say I have enough experience with other to make effective conjectures.) We will look at an intersection crash (FMVSS 214) or a nearly head-on (IIHS 25 or 40%)(two very standard tests done all the time by manufactures) with a typical passcar as the other vehicle. The occupants of the RV will be largely above the intrusion in either case. The basic mass of the RV will reduce the impact on the RV's occupants. The shell of most RVs - even the bus-based will provide little protection in a side impact (214). What happens in a nose-to-nose is very dependent on vehicle design, but the driver will still be above the primary impact.
Just a note: In the Recent Anchor Man movie, they roll an antique RV (GMC-TZE). The survival of the vehicle as portrayed in that scene is a fabrication. It was a specially prepared unit. These coaches have been rolled and the occupants survived, but there still wasn't much left and they sure couldn't drive it away. There is often not much left of a conventional wood framed coach rolls or impacts, but still, the occupants have the best chance if they are securely in seats. Those seats have seatbelts that are securely attached to the vehicles primary structure.
Me, I am an engineer that worked in crash testing for a few years.
Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.
