How would you describe the speaker?

Like the speaker in a dramatic monologue, the narrator in Frost’s poem unintentionally reveals much about himself. He does not identify himself or talk about his life, nor does he explain specifically why he is traveling through the snow on the “darkest evening of the year.” Nevertheless, through his voice, his actions, and his reactions to his surroundings, his character is developed clearly. As the poem progresses through the four brief stanzas, it also becomes clear that the narrator is a man to admire.
A telling detail about the character of the narrator is introduced immediately by his actions in the first stanza. He stops to “watch the woods fill up with snow.” His decision to stop suggests several personal traits. He is aware of his surroundings and sensitive to the rhythms of nature; he finds beauty in the natural world and is attuned to it. The image of snow falling in the woods suggests a silence and serenity that speaks to the spirit rather than the intellect, revealing that the narrator is not self-absorbed with the workings of his own mind. Instead, he is open to the beauty of the moment and takes time to acknowledge and appreciate it. Besides revealing the kind of man the narrator is, the stanza quickly establishes what he is not. He is not a man driven by ambition and the relentless need to hurry through life in pursuit of worldly success. By stopping to experience the beauty of snow falling in the woods, the narrator shows that he values nature and feels comfortable in a quiet, isolated landscape apart from society.
The narrator’s character is developed further in stanzas two and three as he speaks of his horse. His reference to “my little horse” is affectionate, and from his subsequent personification of the “little horse,” it’s easy to infer that he thinks of the horse as his companion, not as a subjugated animal in harness. The narrator and his “little horse” understand each other’s behavior, suggesting they have travelled together many times. Consequently, the narrator knows what his horse must be thinking when they stop for no apparent reason “between the woods and frozen lake.” The bond between the narrator and his horse underscores the narrator’s sensitivity and perception; the affection he feels for his “little horse” reveals a gentle and loving spirit.
As the poem concludes, the first line of the fourth stanza serves to reprise much of what the narrator has revealed about himself in the previous stanzas. “The woods are lovely, dark and deep,” he observes, indicating once again that he is sensitive to the beauty of the natural world and finds wonder in it. The reader can almost hear him sigh as he describes the scene before him. In the final three lines of the stanza, additional traits in his character now become evident. He has “promises to keep” and will travel far through the dark, snowy night, without rest, in order to honor them. A promise is a vow, indicative of commitment; to keep a promise implies dedication and a sense of personal responsibility. “[I have] miles to go before I sleep,” the narrator says, reluctantly turning away from the peaceful scene that invites him to linger. A good man through and through, he can delay no longer in keeping his word.