Robert Frost's poem "The Road Not Taken" has proven to be a poem that lends itself to increasingly many and very different interpretations. One common interpretation is that the poem is a metaphor for the choices people must make in life and a parody of peoples' thought processes as they choose. Along with this interpretation comes the belief that the road "less traveled by" was the path that represents the most morally righteous path and the one that brought the speaker the most success.
Parody in the speaker's choices is seen in the speaker's observations about the roads, observations that are a bit contradictory. He spends equal time looking at both roads and thinks both roads look "just as fair" but feels the other has "perhaps the better claim" because it looks grassier and less used than the other road. Yet by the third stanza, he observes that both roads "equally lay / In leaves" that had not yet been trodden by feet. Hence, he shows confusion so common in choice-makers: First he notes the differences; then, he notes the similarities for such a long time that differences and similarities seem to blend all into one. This confusion in the choice-maker can be seen as moderately amusing, showing us that Frost is parodying choice-makers.
Yet, by the end of the poem, the choice-maker is convinced he has taken the road "less traveled by." We can see the two opposing roads, one more traveled and one less traveled, as metaphors for moral and immoral behavior. It can be said to be much more common for people to choose the immoral, irreligious path; therefore, the moral, religious path is always the one "less traveled," showing us that the roads serve as metaphors for moral and immoral choices. Hence, it can be said that when the speaker ends with "And that has made all the difference," though he may have some lingering questions, maybe even doubts, about his choice, he is ultimately happy and triumphant in his choice.
While in TV commercials and greeting cards, Robert Frost's "The Road Not Taken" is treated as a straightforward exhortation to be non-conformist, the poem itself is more open to irony and parody than one might expect.
Part of the ambiguity of the poem rests in the tension between the title, "The Road NOT Taken" (my emphasis) and the concluding lines "I took the one less traveled by,/ And that has made all the difference." We are left to ponder what the real "difference" was between the two roads. it may be easy to assume that the concluding sentence is ending on an uplifting, positive reflection, yet the speaker confesses that in the future he "shall be telling this with a sigh," which could suggest either fondness or regret.
Frost is using the ambiguous meaning of words like "difference" and "sigh" to create humorous puns on the rhetoric of decision making. Instead the poem treats the choice of roads as just that -- a choice. We are not given a definitive answer about whether one choice is more preferable or even consequential. In fact, both roads are described as "fair" and "equally lay /in leaves no step had trodden back." Both roads will lead on to others, and the speaker suggests that he likely will not be presented with the choice again, which seems fine to the speaker. The importance lies less on choosing the right road, and more on the speakers expectation that he will lend this choice meaning in the future.