Headscratchers / Duel

• When David confronts the trucker who he thinks is the one harassing him, why doesn't he ask him which truck is his first before accusing him? It would've saved him the pain and embarrassment.
  • The original TV edit of the film shows that David saw the guy wearing boots identical to the one he saw at the gas station which made him incorrectly assume that he was the guy harassing him so in his mind he didn't need to make sure; the boots were evidence enough.
  • Also, to be fair to him the guy is increasingly harassed and on-edge. He's not thinking straight.
• Not siding with the homicidal truck driver, but why does he blow his horn when he's barreling towards the phone booth while David's trying to report him? He didn't know the guy was coming until he blew his horn so he could've just plowed into the booth, killed David, and that'd be it.
  • There are several points where the truck could have just killed him. It's implied that it was just toying with him before it went for the kill.
  • The driver wanted to continue playing his game and finish David off on the road. He demolished the phone booth to prevent the police from getting involved, but gave him enough warning to get out so they could continue to play.
• Why does David keep driving for his business meeting? He appears to live in Los Angeles (the opening shows him driving through downtown L.A.), and most of the movie appears to take place in the backroads of California's central valley. If he wanted to be home by 6:30pm, he should be heading home around 2:00pm or 3:00pm, yet he keeps trudging towards his meeting long past noon. Even if he had realized that he couldn't get home in time, there's a point where he should realize the meeting is a loss, and it'd be safer for him to return to a major metropolitan center instead.
• For that matter, what kind of route is David taking anyway? He starts off going north out of Los Angeles on Interstate 5, then spends most of the movie off the interstate in the mountains. It doesn't seem feasible that an important client would be living in a remote location far from any major cities or highways, yet the bulk of the movie takes place on remote roads where two lanes are a luxury.
  • The simple answer to both of the above questions is: he's being chased by a terrifying truck. The protagonist's goal clearly stops being about "must get to my meeting on time" or "must get home by 6.30" fairly early on, and instead becomes "must find a way to escape or destroy this terrifying truck that's following me around and harassing / trying to kill me". Furthermore, the truck is clearly playing cat-and-mouse with him; ergo, we can simply take as read that it's actively steering him away from any possible routes to safety in order to keep him lost, isolated and alone.
  • Remember also that this is the 1970s. If you wanted to find your way anywhere, you couldn't rely on GPS. No Google Street View to help you plan your route and ID local landmarks. At best you had a map in your glove box, and the hope that it was reasonably up-to-date. You take the wrong turn at any point, even accidentally — and never mind if a hostile fellow road-user is waylaying you — it's easy to find yourself lost and miles away from your intended route, and hard to find your way back. This is where part of the tension of the film comes from — a driver, lost on unfamiliar roads, being hunted by someone with malevolent intentions towards him.
  • Furthermore, to be fair, much of this is just basic Rule of Drama. The story is a thriller set along a deserted highway about a guy in a car being terrorised by a massive truck. If you take the man out of the deserted highway and put him in a city where the truck's malevolence is more apparent and there are more people to help him, you lose the thriller. So the story works to keep him alone on the deserted highway.

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