Yeah this is an interesting point. What constitutes a "traffic light"? Just the bulb? The housing around it? Or the pole as well? What about the control unit? They won't function as "traffic lights" without that. Remove the control box, and they become just dumb street furniture with no purpose.

Do they need to be on a road to be traffic lights? If I took the lights, the pole, and the control unit and installed it in a forest, would it still be "traffic lights"?

Huh that might be why I keep failing those traffic light ones, I was only including the bit with the lights, not the poles also.