OK, so this is a very troubled man — or Man, as he is identified in the script, with no name attached. But why start the action here? It means we don’t have any mystery, and thus narrative tension, as to how far Man can and will go. Maybe this is why the 90-minute running time will still feel bloated.

We then get a documentary-style lesson, during opening credits, on the plague of road rage. We hear news commentators saying deep things about anger, like “When you’re very angry you lose a lot of self-control.” Also: “People have so much coming at them that their brains can’t handle it.” (This is pre-pandemic. You want to shout at the screen: “Tell us about it!”)

But, you think, maybe there’s something interesting to explore? The precipitating incident is simple: Harried mom Rachel (Caren Pistorius, doing her best to differentiate levels of fear behind the wheel), is going through her own divorce and trying to raise a school-aged son (a sensitive Gabriel Bateman, who like everyone here deserves a better movie). Of course she’s late getting him to school, because she’s a harried single mom in the movies.

Stopped at a red light, Rachel honks at the guy who fails to move when the light changes, then flips him off. This is, as Julia Roberts would say in “Pretty Woman,” a big, huge mistake. He asks her to apologize. She doesn’t. And the rampage begins.