Wiktionary
sidewalk superintendent
n. (context construction English) A passer-by or other person who watches work at a construction project from a sidewalk or other vantage point.
Usage examples of "sidewalk superintendent".
They had stepped across to Shed B and were looking in, each with his own window in the roll-up door facing the rear of the barracks, each in that sidewalk superintendent posture I knew so well.
And tell this bushy-tailed sidewalk superintendent that I need no help.
Now it was no more than the size of a knothole which a sidewalk superintendent might stoop to snoop through on an interesting piece of building construction.