CB channel 13....... I have a decal saying that and most of the time it's pretty quiet,but every once in awhile I'll find someone there. It is also amazing just how often on 18-19,you can get road info just by asking and no four letter words.There aren't very many Ham radios out there and cell phones don't cut it when trying to talk from one rig to another and you don't know their phone number. Besides it's against the law in a lot of states to use them when you're driving.
In the Final Rule,The federal Law on the use of cell phones while driving a truck or bus,it is a fine of $2750 if you're caught talking on a hand held cell phone. Also, a couple of those and you lose your CDL. The policy of the school district where I drive is that if you're caught by the boss or a LEO, YOU'RE GONE.