Those things drive me nuts. There is a walking path that I frequent, and I can't use it at night because they are spaced every 20-30 feet. When I am not under them, they are off and my eyes adjust to the darkness and as I pass under one it flips to full daytime brightness and blinds me. As soon as I walk away from it, everything goes dark again, but my eyes had adjusted to the daytime brightness of the lamps. And I know that in 30 feet, I have to do it again, for the next couple of miles.