Sometimes having moved from the Midwest to the East Coast feels a little like having moved to a foreign country. I am going to guess that this thing is for a crossing guard, and that there are manual traffic light overrides inside. Back in Kansas school kids (like other pedestrians) are just on their own. Result: parents frequently drive their kids to school even if it's just a few blocks, and schools are hotspots of bad air quality.
@gamehawk I wonder if its also intended as a place for the crossing guard to stay warm and stay out of the rain or snow while they wait for kids to come?