I have been pulling my OFF-ROAD POPUP trailer since 2008 and monitoring CH19 with my CB radio mounted under the seat of my TRUCK.
Have never heard another CB'er on it.
My OFF-ROAD POPUP has very visible ANTENNAs mounted on its roof indicating radio operations. My truck also has roof mounted radio antennas and HAM CALL SIGN TAGS.
I like to have the CB radio on Ch19 to listen to the truck road reports... I actually have the SQUELCH turned up all the way to insure I only have close proximity operations just in front or behind me going down the public roads...
The Wife and I use FRS RADIOS to stay in touch when walking around the local towns and campgrounds.
All other times we use the cell phone service...
Roy ken