Though you’d have to buy an e-subscription to read the full article, this link describes a new energy-saving street lamp that has a super sensitive sensor on it, enabling the lamps to gradually dim as the night sky fades to daylight. I think it’s interesting that this project hasn’t been introduced sooner, as the technology for light sensors has been around for a while now. Nevertheless, if the cost of implementation is less than the proposed number of dollars saved, it’d be nice to have around.