Revealing mistake: As Nightrider's car hits the pile up, you can see a small explosion toss dirt in the air a split second before the car hits. (00:12:05)
Revealing mistake: When the motorcycles are chasing the guy and his girl in the red car, one of the motorcycle riders attacks the car with a machete. He first hits the side of the car, and then goes to hit the windshield. Notice the windshield is already cracked prior to the machete making contact.
Revealing mistake: When bikers ride over Max's arm; a small hole in the asphalt under Max's arm can be seen.
Revealing mistake: When Goose puts his crashed bike in the back of the pick up truck you can see foil wrapped around the spokes to simulate the mag wheels. The budget was so tight they could not afford a second set of mag wheels for the stunt bike.
Revealing mistake: After Max takes up the chase and is on Nightrider's tail, you can see that the driver of the cop car is a stunt driver, as he appears to have a hat on. Also, there appears to be a helmeted figure in the passenger seat where there is supposed to be nobody.
Chosen answer: It was nuclear war. Tectonic plate movement could make ports dry and flood others. None of the movies ever goes into great detail about the apocalypse.
Grumpy Scot