In both "The Road Not Taken" and "Fifteen," the speakers are on the edge of an adventurous journey in a natural and secluded area--the woods and the "back of the woods" south of a bridge at the edge of town, respectively. Both speakers become cautious and do not to venture forth into areas that may prove risky. In contrast, though, at the end of their narratives, the speaker of Frost's poem expresses a certain self-doubt and incompleteness while the speaker of Stafford's poem feels self-restoration.
As he takes a walk, Frost's speaker discovers two enticing lanes in the woods that are "untrodden,"
...long I stood
And looked down one as far as I could
Stafford's speaker, on the other hand, discovers a running motorcycle that attracts him with the prospect of a new, exciting adventure. The object at which he looks assumes a femininity that is seductive:
I admired all that pulsing gleam, the
shiny flanks, the demure headlights
fringed where it lay
Further, the speaker of "Fifteen" indulges delightedly in his imagination of the adventure that he can have with this machine, and he even takes it to the road. But as he has "a forward feeling" and there is a tremble, he changes his mind and returns with the motorcycle to the place he has found it. "Thinking," he finds the owner, whose hand is bleeding. He helps the owner to his motorcycle and the other calls him a "good man" and rides off.
Both the bridge where the fifteen-year-old feels the "forward feeling" but resists it and the point where the two roads "diverged" and the speaker chooses the one more traveled are junctures in the lives of the speakers of the two poems. These choices that the speakers have made are for what is real over that which is imagined. For both speakers there is a sense of loss and a change in themselves; in contrast, however, Stafford's speaker has grown from his experience, while Frost's speaker merely reflects that his choice "has made all the difference" to him.