I often make such decisions when walking. Shall I follow this trail or that through the forest preserve? I would like to follow both, but then there is only so much daylight. I can also see this poem originating because of Frost's walks with Edward Thomas as Aunt Shecky and this article note:
http://en.wikipedia.org/wiki/The_Road_Not_Taken
However, even the Wikipedia article I cite has this to say:
The poem, besides being among the best known, is also one of the most misunderstood.
More than the poem itself, that idea is what I think needs to be critically examined. Is this poem really so "misunderstood"? I don't think so. The interpretations of the poem provided by many in this thread show adequate understanding of the poem and Kilgore's alternate interpretation doesn't fit the poem well at all.
Although Frost writes that he's "sorry", Paulclem, how does this validate Kilgore's interpretation: "He is lamenting life's choices and the relentless one-way march of time, in a wistful, quiet, lonely little poem whose speaker has no idea whether he took the right path or not, does not brag, offers no advice, hints that life is rather unfair, and seems on the whole more oppressed and puzzled than anyone."
Frost, or perhaps it was Edward Thomas, whom Frost may have been describing, doesn't seem any more oppressed and puzzled than I would be choosing trails to walk through the forest preserves around Chicago.