Calistan

There's a YouTube video where he explains

• it's about El Camino Real, a road that extends 600 miles down through California;
• the radio is CB and the Big Fleet is all the truckers on the highways;
• the weather refers to the smog in LA.

I wish he'd said more about the more speculative elements (like LA being a valley of tar) but that's what's there.

https://www.youtube.com/watch?v=qik7gjekizk