> are they really that arrogant to think they can ignore the litany of signs

Bingo! If you work in the field for long enough, or actually not even that long you're going to run into the driver who sees themselves as having a skill level way above the norm and can pull off tricks that mere mortal drivers would flinch at.

"You'll get stuck!" Cue Arrogance/ignorance rush. "Heh, heh, Well maybe a 'regular' driver would but I've been haulin' freight for.... ^dornes ^on ^and ^on."

Yeah, way too many hours alone in the cab can start one believing their own bullshit. That and the temptation of a 'shorter' route can be a real trap, as stuck between some rocks trap. ¯\_( ͡❛ ͜ʖ ͡❛)_/¯