I recall seeing one right about
here (where the green arrow points) on Cottage St., Hudson MA. It might have been a little closer to the edge of the street.
My only memory of it is waving to the operator during a walk with my grandfather Coolidge when my brothers and I were small, 1956-ish. Didn't really notice it any other time I was near the crossing. In the day, it might have also controlled Warner St. I don't recall any gates. We must have seen a steam locomotive that day, because I do recall my grandfather saying "Look out you don't get a cinder in your eye."
I think the street sloped downhill toward the crossing when coming from the Central St. end, with the track being in kind of a "cut" behind the home on the SE corner and curving slightly as it went toward Warner St., so the sight distance for road users might have been somewhat limited.
I wish Street View was available there. Might be the only way to tell it had ever been a RR ROW.