Mark T’s review published on Letterboxd:
Duel is probably the most literal example of "nightmare fuel" I have ever seen.
Despite the TV movie limitations, Steven Spielberg has managed to convey an illogical yet completely visceral thriller better than most filmmakers today. And considering that this is widely recognized as his feature debut, that's even more impressive. The masterful editing, carefully planned shots, and insane premise create an engulfing atmosphere that only gets more tense as it goes along. Not to mention, the fact we never see the truck driver adds a sense of mystery to the proceedings, therefore placing the audience in the same point of view as our protagonist.
Watching this, I got the impression that Spielberg wanted to create the perfect picture of a nightmare. Between the lack of character development and an ending that makes little sense, it seems that logic is thrown out the window for pure emotion. This actually works in favor to the story because Spielberg is 100% willing to manipulate the viewer to feel whatever emotion is appropriate for the scene. There are moments, like the diner and phone booth scenes, that are incredibly suspenseful because of the cutting and shot choices. The diner scene, for example, features a long, unbroken shot following the protagonist, which adds suspense in that we don't know when the truck driver will show up next.
Being that this is one of Spielberg's first films, there are a few rough patches. The biggest flaw is the narration, which is used inappropriately to tell the audience how the main character feels. This is a problem because we constantly see how he reacts towards situations, so adding a voiceover adds virtually nothing to the character. Another issue is that even with its 90 minute runtime, it gets repetitive regarding the scenarios, reinforcing the conflict more than it needs to be. This caveat also makes it clear how this was adapted from a short story, and maybe this could be avoided had it been a short film.
Duel is one of the few directorial debuts that stands alone as an expertly-constructed thriller, not just some flag post to mark the introduction of such an influential filmmaker. It unequivocally shows how talented Spielberg is as a director, and how capable he is of improving himself with his then-upcoming projects. Pretty fantastic for a movie just about a man being chased by a truck.