I have mine on all of the time when traveling. However, I keep the squelch turned all the way up (or down, whichever applies to keeping the radio quiet). I find that the only time I really hear anything on it is when there is a major traffic tie up on the highway.
In the many times that I've made the attempt, I have yet to raise another RV on it while going down the road and spotting another. Tried on both CH13 and CH19.
A CB radio can be very handy. Just wait until you need assistance on the road, and find out that you have no cell service where you are....;)