to communicate with other riders on the trail... or even on the way to the trial.

 

Yup, this ^^. Donnie beat me to it. When I go wheelin with friends there's always chatter on the CB. Then you don't have to stop, get out, and walk up to someone's window to give them crap about not making an obstacle.

Plus, if you're ever in an emergency you have an alternative means of trying to reach someone. Yeah it's more of a shot in the dark these days, but multiple lines of communication is always a good idea.