The availability of Citizen Band "CB" radios made these "convoys" popular in the 70's.
They could let other truckers know about "Smokeys" (state police wearing those big 10 gallon hats that looked like the hat worn by Smokey Bear), good places to stop and so on.
Non-truckers started buying those radios and the truckers' lingo became quite popular .
https://www.youtube.com/watch?v=Sd5ZLJWQmss