Outskirts is a tiny poem that paints a whole edge-of-town scene in three lines. The speaker looks at a place where a city thins out into something unfinished: a "blind place," somewhere with no view, no landmarks, maybe no one paying attention. Nothing is named beyond the rails, so we fill in the rest ourselves, perhaps weeds, gravel, and fences.
The most striking move is the idea that the rails have "an agreement / not to conclude." Tracks can't really make agreements, so the speaker is giving them a quiet will of their own. They seem to stretch on, unwilling to stop. The dash at the end leaves the sentence hanging, which does the same thing: the poem itself doesn't conclude.
The mood is calm, a little eerie, and open-ended. The speaker doesn't seem upset. Instead there's a sense of wonder at places that sit between one thing and another, and at journeys that don't have clear endings.