Continuity mistake: On the truck cab's rear window, there is some sort of air conditioning unit installed. In some shots, such as the gas station scene where David Mann is on the telephone, or the railroad crossing scene, the air conditioning unit has a support structure to hold it in place. In the rest of the film however, there is not any support structure to be seen.
Continuity mistake: When David Mann crashes his car against the truck near the end of the movie, the car's frontal bodywork inexplicably returns as brand new in one shot and back smashed again.
Continuity mistake: When David crashes his car into the fence at Chuck's cafe, it shows that it was the passenger side that crashed into the fence. The driver side is undamaged. However when David exits his car to help the bus driver, there is significant damage to the driver's side of his car. (00:26:40 - 00:44:25)
Continuity mistake: When David has the accident and crashes his car against the fences, he steps out of it and closes the door, but when he comes back to go on his own way, the car door is inexplicably open. (00:26:49 - 00:42:52)
Continuity mistake: In the first scenes when Weaver first encountered the truck he is pictured in various states of seatbelt wearing. In some scenes it's down and across, in others nothing.
Continuity mistake: Towards the end of the movie where David begins to take advantage over the truck driver, and he turns on right towards the climb also breaking the cartels and fences, the weather changes in two shots: it's cloudy before and sunny immediately after.
Continuity mistake: After the truck tried to make David's car hit by the train dabbing it from behind, the car has a dent on the right rear light, but in a following scene, the dent has vanished. (00:53:09 - 00:54:30)
Continuity mistake: Visible on the theatrical release. After David has overtaken the truck, you can see from the interior shot that David has his seat belt on. A few seconds later in the external shot David is no longer wearing his seat belt. (00:08:10)
Continuity mistake: When David returns on his way after sleeping, he first wears his glasses in a shot, but when he suddenly brakes after seeing the truck stopped on the side of the highway, his glasses are gone. (01:03:07)
Chosen answer: The movie opens with him in downtown Los Angeles, California, so he's probably from there or somewhere in Southern California. He's heading to Bakersfield, California, which is north, about 2 hours away. In the short story, he's heading to a client in San Francisco. However, in the film he gets off the main freeway running from LA to Bakersfield (IH-5) and takes Highway 14 towards Canyon Country.
Bishop73