I'm guessing they might be more freaked by the movement than anything else. Dividers should help but you should also create "cat zones" places they can feel comfortable in, higher up probably the better, or nearest windows they can look out. You didn't say whether or not your driving solo. If solo I would think you would want them in crates, as much as you don't want to do it.
I can only imagine, you buy your brand new rv, only to have the cats marking their territory's in it and/or making their own scratching posts...while you drive. Sounds like a recipe for disaster in my opinion.
If you have someone with you that can keep an eye on them, different story. You also need to have secure spots for litter, food/water, etc. Dogs will bark and tell you they need to go. Cats just go. lol
