Four minutes into the film, we see a cue ball break up a racked set of pool balls. Ruby then picks up the cue ball, moves it a couple of feet, and plays a shot, but the numbered balls are in their initial positions again.
When Jack parks his rig at Ruby's diner, he does so nose-in against a section of fence marked "Jack's Spot". A semi driver would normally choose to park where he wouldn't have to back up at all, and the diner's parking lot has ample space to do that. If he did have to park in such a spot, he would normally choose to back in rather than have to back out later.
The movie often refers to the music of Frank Sinatra, but what can be heard is Roy Orbison.
During the opening credits, the road train is filmed from the air. A helicopter's shadow (presumably the helicopter doing the filming) can be seen briefly on the ground below.