Duel is a 1971 television film about a terrified motorist (played by Dennis Weaver) on a remote and lonely road being chased and stalked by a huge tanker truck and its unseen, psychotic driver. It was the first feature film directed by Steven Spielberg and was written by Richard Matheson based on his own short story.
David Mann (Dennis Weaver) is a middle-aged Los Angeles electronics salesman driving his Plymouth Valiant on a business trip. On a two-lane highway in the California desert, he encounters a grimy and rusty gasoline tanker truck, a Peterbilt 281, traveling slower than the speed limit and expelling thick plumes of sooty diesel exhaust. Mann passes the unsightly truck which in turn, promptly roars past him and slows down. Mann passes the truck a second time and is startled when it suddenly issues a long air horn blast.
The truck follows him into a filling station. While there, Mann makes a phone call to his wife (Jacqueline Scott), who is a bit annoyed with him for not confronting one of their friends at a recent party who was making a pass at her. Mann argues that the friend had had too much to drink and did not require that kind of overreaction. His wife’s anger cools but she chides him for always being one who tends to avoid confrontation. The gas station attendant mentions that Mann needs a new radiator hose, but Mann casually puts that off for the moment.
Back on the road, Mann allows the truck to overtake his Plymouth, the truck slows and soon begins blocking Mann’s path each time he attempts to pass the truck. At one point, the truck driver waves at Mann, indicating that he can overtake. When he does, he almost slams head-on into an approaching sport utility vehicle. Mann soon decides that the truck driver was trying to trick him into a fatal collision. He passes the truck again, using an unpaved turnout next to the highway. The truck soon begins to tailgate Mann at high speeds — over 90 miles per hour (140 km/h) — forcing him to maintain his speed to avoid being hit by the truck from behind. The chase continues down a mountain road with the truck bumping him several times until the Plymouth goes off the road, colliding with a guardrail across the road from a diner. The truck keeps driving.
Mann enters the diner (Chuck’s Café) to compose himself. After returning from the restroom, he is shocked to see the truck parked outside the diner. Mann studies the diner patrons carefully and begins an inner monologue in which he contemplates the driver’s motives and second-guesses his decision to sit helplessly in the diner. Most of the patrons sitting at the counter give Mann the impression of malice, but when one leaves, appearing to approach the tanker, he instead drives away in a pickup truck. Mann eyes the patrons again to try to identify his pursuer, and when he thinks he has, he confronts him. The man he approaches, however, is angered at Mann’s accusations and engages him in a short fist fight. After the fight is broken up by the café owner, the man abruptly leaves the diner in a livestock truck. As it turns out, the tanker’s driver had never entered the diner and suddenly drives off before Mann can get a look at him.
Mann leaves Chuck’s Café and stops to help a stranded school bus, but his front bumper becomes caught underneath the rear of the bus. The truck appears at the end of a tunnel. Mann panics, manages to free the Plymouth and flees, but then is puzzled to see the truck helping the bus get moving. At a railroad crossing, the truck quietly approaches Mann’s car from behind and starts pushing the Valiant towards a passing freight train. The train passes by just in time and Mann crosses the tracks and pulls off the road. The truck passes him by and disappears.
Mann then stops at Sally’s Snakerama Gas Station to call the police and refuel his Plymouth. Before he can make the call, the truck roars up and plows into the telephone booth, with Mann barely jumping clear in time. The truck proceeds to chase Mann as he is on foot, destroying Sally’s Snakerama. Terrified, Mann jumps into his car and speeds away. Mann then hides behind an embankment off the road and sees the truck pass by, apparently without noticing him. After a long wait, Mann heads off again but is dumbfounded to see that the truck is waiting for him just around the bend. Mann stops his car and attempts to get help from an older couple in a car that is cruising by. They think he is crazy and refuse to listen — until they see the truck themselves, and flee when the truck backs up towards them at increasing speed. Mann returns to his car. The truck eventually allows him to pass by and a high-speed chase begins. Mann races up steep grades, putting some distance between himself and the truck. However, his Valiant begins to overheat when its weak radiator hose fails and the truck quickly begins gaining on him. Mann barely makes the summit and coasts down the other side in neutral as the truck bears down on him.
Descending at speeds too great to control, the Plymouth spins out and impacts a rock wall. The truck speeds toward the damaged car as Mann accelerates, drives up a dirt road, and turns to face his opponent on a large hill overlooking a canyon. He places his briefcase on the accelerator and steers his vehicle directly toward the oncoming truck, jumping from the car at the last moment. The tanker hits the car, which bursts into flames, partially obscuring the truck driver’s view. Too late, the truck’s driver realizes he is headed for the canyon and brakes hard. With a blast of the air horn the truck plunges over the edge of a cliff into the canyon below. Surveying the smoking wreckage, Mann celebrates his victory and then sits down, exhausted. He tosses stones over the cliff as the sun sets.