Trucker lingo-- does anyone know what this conversation means?

I’m not sure, but I think he’s saying that he’s running a bare trailer… no load.

and the reason you heard it over the PA in the restaurant was that the trucker you heard was likely using a power booster – illegal – and the extra power found the wires in the PA and used ‘em as an antenna of sorts to broadcast the transmission. I was hitchhiking in Mississippi as a lad and got picked up by a guy using a power boost and we ended up talking to someone in San Francisco!

I used to drive long-haul back in the 80’s, but I’ve been out of it for too long now, so I don’t know what this phrase is referencing. However, what @CaptainHarley says sounds logical to me.

Captain Harley may be correct. It could also apply to a flatbed trailer without a load.

Most tractor-trailers, without a load or a governor on the engine, can make speeds up to 85 mph. Tracked them with laser radar many times.

And, most truckers tell me that their rig will only go 72 mph…..not so.

Thanks for the helpful answers! My kids are into learning new languages and this experience fascinated them (and me, honestly) to hear English slang they couldn’t understand. :)