Duel is a 1971 television (and later full-length theatrical) film directed by Steven Spielberg and written by Richard Matheson, based on his short story. It stars Dennis Weaver, who plays a terrified motorist stalked on a remote and lonely road by the unseen driver of a mysterious tanker truck.
David Mann (Dennis Weaver) is a middle-aged Los Angeles electronics salesman driving his red 1971 Plymouth Valiant Signet on a business trip. On a two-lane highway in the California desert, he encounters a grimy and rusty 1955 Peterbilt 281 Tanker truck, traveling slower than the speed limit and expelling thick plumes of sooty diesel exhaust. Mann passes the unsightly truck, which promptly roars past him and then 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 upset with him for not confronting one of their friends at a recent party who was making a pass at her. The gas station attendant mentions that Mann needs a new radiator hose, but he disbelieves the attendant and refuses the repair.
Once both Mann and the trucker are back on the road, the truck begins blocking Mann’s path each time he attempts to pass it. At one point, the truck driver (Carey Loftin) waves at Mann, indicating that he can overtake. When he does, he almost strikes an oncoming vehicle. Mann realizes 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 rear-ended. 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 going.
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 (Eugene Dynarski) is angered by Mann's accusations and engages him in a short fist fight. After the fight is broken up by the café owner, the falsely-accused man drives away in a livestock truck; the tanker truck leaves a few seconds later, suggesting that Mann's tormenter was never in the diner in the first place.
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 eventually catches up to the truck as it has stopped, as though it were waiting for him.
Mann then stops at Sally's Snakerama Gas Station to call the police and refuel his Plymouth. The truck has stopped just a little further up the road, seeming to contemplate what's about to happen. As if an epiphany has taken place, the truck realizes that Mann is up to something. Before he can complete his phone call, the truck roars up and plows into the telephone booth, with Mann jumping clear just in time. The truck proceeds to chase Mann as he is on foot, destroying Sally's Snakerama and releasing several rattlesnakes that had been caged on the premises. 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, destroying the truck and killing the crazed truck driver. Above the smoking wreckage Mann sits exhausted at the cliff's edge tossing stones into the abyss as the sun sets.
- Dennis Weaver as David Mann
- Jacqueline Scott as Mrs. Mann
- Carey Loftin as The Truck Driver
- Eddie Firestone as Café owner
- Lou Frizzell as Bus driver
- Eugene Dynarski as Man in café
- Lucille Benson as Lady at Snakerama
- Tim Herbert as Gas station attendant
- Charles Seel as Old man
- Shirley O'Hara as Waitress
- Alexander Lockwood as Old man in car
- Amy Douglass as Old woman in car
- Sweet Dick Whittington as Radio interviewer
- Dale Van Sickel as Stunt Car driver