This is a poem with many levels. On the surface, it is basically a simple story about a man and a horse who stop by some woods on an evening when it happens to be snowing. However, the poem’s deeper meaning is about death. The poem can also be seen as a metaphor for suicide.
The poem begins when the speaker stops to look at the woods. He does not think he will be bothered because although he is not sure who the land belongs to, he thinks his house is “in thevillage” so he can’t stop there and think, watching the snow on “the darkest evening of the year” (line 8).
The horse does not want to stop, and “gives his harness bells a shake” (line 9). The noise brings the speaker out of his revelry, and he realizes that he still has “miles to go” and “promises to keep” (stanza 4).
On a deeper level, this poem can be referred to as a metaphor about a person considering suicide. The “darkest evening of the year” might be a mental darkness. The person might be pondering death. However, something urges the person on, and he realizes that he still has a lot of living to do and promises to keep, perhaps to himself and perhaps to others.