It may not always be possible, but when it is, try to check out your routes before you try to take your RVs on them. Its not a bad idea for tent campers either, but RVs are more vulnerable and more difficult to manage if you encounter damaged roads or detours. If you are only going to be driving on freeways or major highways you probably only need to determine if there are any construction detours or traffic accidents that will impede your travel. You can usually do that on your state DOT web site or via Tripadvisor.com. But whenever you move off onto secondary roads and especially if you expect to be traveling on dirt or gravel roads to reach remote campgrounds or dispersed camping sites you need to get as much information about the route as possible. When you can, take a drive in a car, motorcycle, or better yet a 4WD vehicle to familiarize yourself with your planned route before you head down the road in your motorhome or towing your trailer. Its a lot easier to avoid a bad situation -- or get out of one -- in a smaller vehicle and then plan another route or another trip for your "big rig" if you encounter difficult terrain. I like to use my 4wd pickup for pre-trip route checks. That way, if I do encounter mudslides other difficulties I will be better prepared. If you can't pre-drive your route, be sure to talk to someone who knows it well enough to advise you if it is compatible with your rig, preferably someone who as driven something similar to your rig on the same route. Previewing your route is especially important if any segments will be in primitive areas where you may be exploring poorly maintained roads or even going off-road but it is still a good idea to checkout your planned on-road routes too. Maps don't always identify weight, height, or length limitations or other situations, like road construction, mudslides, or repairs, that might make RV travel inadvisable. When you can, check out the route via the Internet. Any construction or even accidents along most major highways will usually be reported on state Department of Transportation (DOT) web sites, allowing you to make alternate plans to avoid lengthy, boring, fuel and time wasting delays.
Make sure your information is up to date. A recent rain may have washed out bridges or roads so even when headed to places you've been before, get up to date information before you leave home. I once encountered a whole section of a familiar paved state highway I often used that had become impassable from rain that came down while I was en route. Much of the road was covered with mud and rocks that had been washed down and most of the entire lane on the downhill side of the road had been completely washed away.
Not long ago we fell into the unknown route trap and ended up with a lot of regrets. We had asked someone who should have been knowledgeable (bus wasn't if the route was OK for our big motorhome and motorcycle trailer (total length about 55'). Following the instructions we were given, we started down a dirt road into a big sand wash to locate an OHV group we were supposed to be camping and riding with based solely on some simple but incomplete directions from a fellow rider. There were already several groups of large RVs camped below so we assumed there was reasonable access. Bad assumption! What appeared to be the main access road down into the wash petered out without warning after a few hundred yards down the hill. We soon found ourselves on a narrow, rocky, sandy "road" that promised great trials coming back out and delivered some rather nasty tweaking of our rig on the way down. We did in fact get stuck in the deep sand trying to get back out. Thanks to the skills of some good Samaritans from a nearby camp who happened to be experienced over-the-road truck drivers, we were able to get our rig (40' motorhome and 15' enclosed motorcycle trailer) towed and backed down out of the sand so we could drive out another way. Turns out there were at least three paths down the hill and none of them were very compatible with a rig our size. By the time we got out, we had leaks near the water heater, both holding tanks were dripping, and the rather expensive electric tongue jack on our motorcycle trailer was damaged beyond repair. We could have saved ourselves a lot of aggravation and expense by walking or otherwise checking out the route prior to committing ourselves in our 40' motorhome and 15' enclosed motorcycle trailer. We were lulled into a sense of security by the presence of many large rigs clustered in several groups on the valley floor, but obviously they must have chosen a different route than we did, probably one that entered through one end of the valley. The one we drove down appeared to be the "main road" when we started on it but it quickly petered out to become inadequate for just about anything but an OHV, 4 wheel drive vehicle, or a mountain goat! By then there was no place to turn around and backing back up the hill wasn't feasible. In more the 30 years of desert camping in the Mojave Desert we never encountered so many problems total even though we drove into some very remote staging areas, but in looking back, we were either following experienced campers or had become familiar with new areas via our dirt bikes before we attempted to drive our motorhome into previously unknown remote locations. More recently we have pre-driven two different venues for dirt bike outings in our 4x4 pickup, selecting routes and campsites that were comfortably accessible to our rig. We made each trip of exploration into an afternoon sight-seeing tour and picnic and when we returned another time with our motorhome and trailer for an extended outing we could do so with confidence and without incident.
One thing to watch for even on level terrain, are diagonal ruts crossing the road. They don't need to be extremely deep to cause rather severe rocking and tweaking of large rigs, with sometimes devastating results. Ruts that are perpendicular to the road are less likely to tweak your RV, unless you hit them too fast, but diagonal ruts will twist the body severely, even at very low speeds. You can drive slowly over ruts perpendicular to your direction of travel but diagonal ruts will twist your rig no matter how slow and easy you cross them. I once saw a 4x4 mini-pickup stuck in some diagonal ruts. The body was perfectly level but the front and rear axles were at right angles to each other with the right front wheel and left year wheel in a deep ditch and the other two wheels up on the level. Some of the least of the problems are the spilling of contents of cabinets. Having a refrigerator pop open usually offers even more messy problems to deal with. Ruts that cross the road at approximately right angles let both front wheels and both rear wheels drop in and out of the depression at the same time. This causes tilting forward and backward but diagonal ruts drop just one wheel at time, causing twisting and tweaking as well. Tweaking of the body can crack the fiberglass or aluminum skin, sometimes cracks windows and windshields, and even damage the structural framing. It can also crack plumbing and holding tanks creating messy and expensive repairs. If you encounter diagonal ruts that you can't avoid, be sure to ease through them as slowly as possible so the tweaking is as gentle as you can make it. Sudden, violent twists are sure to cause damage. More gentle twisting might create less damage, but any radical twisting, no matter how slow and gentle, is likely to break something. Shifting contents in cabinets, drawers, and tool boxes can occur even on normal roads and can be a really big problem on rough roads. Take extra care opening cabinets after any kind of violent maneuvers to avoid getting a face full of the contents. The stuff in drawers may shift to where the drawer can't even be opened. In that case about all you can do is jiggle it as much as you can to try to get things to settle enough to get it open -- unless there is a way to reach into it from the side or back from an adjacent cabinet or by removing an adjacent drawer. It is always a good idea to organize the contents of your drawers and cabinets in a way that will reduce the chances of jamming when you encounter rough roads or unusually violent maneuvers. Try hard not to overfill drawers as that makes it very difficult to jostle contents down enough to get the drawer open once they've been scrambled by too much bouncing.
Of course if you only camp in developed campgrounds accessible by paved roads you aren't as likely to encounter these kinds of problems compared to off-roaders who by design are headed into remote areas where difficult terrain is to be expected. But that doesn't mean you are entirely exempt from the need to pre-drive your route. Checking things out ahead of time can alert you to potential obstacles, such as narrow roads or narrow bridges, low overpasses, especially steep grades, road construction, and size and weight restrictions. Even when your plans included only paved roads you may sometimes encounter problems created by flash floods or mudslides that would create hazards to your travel, sometimes leaving ruts and other obstacles that are at least as formidable as bad off-road routes. Mud and gravel accumulation from run-off can be deceiving. It may look like you can get over it but often it hides eroded pavement and soft spots where you can get stuck or that can swallow entire rigs, or the weight of the rig may cause the already loosened ground to give way, toppling your rig or send it sliding or tumbling down the slope below the road.
These days you might be able to pre-view some potentially difficult roads using a camera-equipped drone. Be sure it is legal operate drones in the area before launching yours.
Always check it out!