In "Dawn in New York," we know the commute is about to begin when the speaker describes the rising of the sun in the opening lines. At that point, "almost the mighty city is asleep."
As of now, there is "no pushing crowd, no tramping, tramping feet," so the busiest part of the commute has not begun yet. The trains are moving "here and there," so this is the slow part of the morning before the commute really gets going. Hence, it is the very beginning of the morning commute.
However, by the end of the poem, "the shadows wane" as the sun begins to rise. Dawn comes and the narrator goes "darkly-rebel" to work. His commute has begun.
