Red Light (Symbol)
The red light that hangs at the tunnel's entrance is both a literal signal of danger and a symbol for impending death. Whenever the signalman's telegraph bell rings without moving, he leaves his box and looks at the red danger light, because the specter always appears near the light. The danger of which the specter warns is always ambiguous to the signalman, but the specter's appearance near the light always presages death, ultimately predicting the signalman's own.
Tunnel (Symbol)
The signalman's box is situated at the entrance of a train tunnel. The narrator describes the tunnel's abyss-like darkness and earthy smell to emphasize the tunnel's ominous, otherworldly quality. As the narrator learns of the deaths that continually occur at the tunnel's entrance, it becomes clear that the tunnel symbolically demarcates the entrance to the world of the dead.
“Halloa! Below there!” (Motif)
The story's opening phrase is repeated throughout the story. The motif gains new meaning through repetition: innocuous at first, the phrase takes on a haunting quality when the signalman asks the narrator if he said it because the phrase was conveyed to him from some supernatural source. The phrase evidently has a power over the signalman, as he requests that the narrator not call down to him when he visits the next day. The signalman later admits that this is the same phrase the specter uses to catch his attention. While it seems an eerie coincidence to the narrator, the phrase's full significance is revealed at the end of the story, when the train driver explains how he called out "Halloa! Below there!" to the signalman before he struck him down.
