I'm not familiar with the area but I looked at it on Google's Streetview. A signal that remains green on the arterial until cars arrive on the sidestreet is usually "semi-actuated". Most signals these days tend to be fully actuated, but it's not an invalid way to signalize an intersection with relatively minor sidestreet volume.

I'm surprised that the utility company allows them to hang a span wire on their pole, and a long span wire at that. While I can't tell whether the exact position of the heads is correct, at least you have 2 heads in each direction. Many of the signals in Mechanicville only have a single head, including one that's at a one way blind underpass.

Good luck in your quest!