This is a topic I have been studying for awhile now. Depending on where you are geographically, East Coast or West you may find different answers. East Coast has many CB users, the West has moved on to GMRS mostly. Also, CB around truck stops is no longer G rated. Lots of vulgar trash talk.
I have personally found that CBs are very difficult to use successfully in a highly optioned RV due to various items that generate RF. Endless work trying to reduce interference. If you are or can find a skilled CB antenna person, Your luck my vary.
So I have decided to go with a handheld GMRS for ease of use, and my Ham Radio for entertainment when stopped or emergencies.
Ham, unless very skilled and planned, is very hard to use when distracted with driving. GMRS, on the other hand, is similar to CB with a fixed number of channels easily selected when in motion.
There is not a common travel channel for GMRS that I have discovered, so I use 19. My thinking is that this might be a holdover from CB days that others might choose.
Also, there are many GMRS repeaters scattered around various cities that might be useful.
GMRS license for a family is $35.