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: At the end of the film, David Man comes to a dead end, so he spins the car around and waits for the truck to appear. When the truck appears from over the hill, take a look at the very next shot of the truck from the front, and you will notice that the large exhaust on the side of the truck has moved from left to right and back to left again.
Continuity mistake: There are moments in the film, notably during the railroad and pushing sequence where the car's appearance - such as being dirty or clean, changes somewhat; the truck changes during that sequence as well. (The film was first broadcast on TV, then later released to theatres, and the push sequence was specifically filmed for the theatrical release. An identical '71 Plymouth Valiant was used, but a very different truck.)
Visible crew/equipment: During the scene in the gas station with snakes, as Dennis Weaver is wiping the tarantula from his leg, look at the shadow of the old woman behind him. There appears to be a moving crew member shadow next to hers. It cannot be a tank as she wasn't standing next to one either in the shot before or after.
Continuity mistake: When David Mann is at the service station, window cleaner is sprayed on his windshield from the driver's side (camera shot from inside the car). Within a milli-second of the spray stopping, the service attendant is seen on the passenger side of the car. We are only shown one attendant at this station.
Continuity mistake: Near the start of the film, David stops at the gas station. We see him get out of the car and he asks the attendant if he has got change for the telephone. We can see David take out his wallet and pull out a note with the other hand, then puts his wallet away. Then the camera angle changes and his wallet is back in his hand again and he puts it away again. Also you never see the attendant take the note out of Davids hand. It just disappears.
Visible crew/equipment: At the gas station, just before the water is sprayed on the windscreen and the attendant first appears, if you look closely at the top right hand corner of the screen you can see a reflection (albeit for a split second) of a hand giving the cue for the action to begin. Was this Steven Spielberg's hand?
Continuity mistake: When David drives away from the petrol station near the start of the film, you will see the truck catch up with him in the next scene. Take a look at Davids parcel shelf in his car when you see the truck fly round the bend, and you will notice a white baseball cap and a pair of sun glasses on it. They were not there before and also not there for the rest of the film.
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.
Revealing mistake: At the reptile farm, the phone booth Mann uses to try and call for help has no phone lines attached to it, above or below ground (you can see that there are no underground wires when the truck mows the booth down). It's definitely not a wireless/radio telephone, either. There should be lines running to it, but there are none.