A plot involving people panicking and the darkness of human nature have been done several other times--and very well. I like these sorts of stories and "The Monsters are Due on Maple Street" ("The Twilight Zone") and "12 Angry Men" are both great examples of humanity and its dark side. "Night Ride" is a decent look at human nature....but nothing more.
When the episode begins, you see a man scramble onto a subway car-- with police apparently in pursuit. He tells the four others aboard this late night car that a maniac murderer is loose. Soon, the five all start suspecting each other and chaos erupts.
As I already said, this one isn't bad but it suffers for two reasons. First, the pacing is poor. It goes from normal to crazy way too fast. Second, if anyone was the killer, why didn't everyone think it was the guy who jumped on the car last? He did appear to be chased by cops, he knew all about the killer and acted rather guilty. Not among the best written of the "Four Star Playhouse" episodes.