Cities that installed LED traffic lights to save money are learning that the incandescent lights they got rid of had a useful purpose: their waste heat melted the snow that covered them in winter storms.
Municipalities around the country are taking different steps to keep their signals shining brightly in the face of Mother Nature. Crews in St. Paul, Minnesota, use compressed air to keep their lights clean. In Green Bay, Wisconsin, city workers brush the snow off by hand in a labor-intensive process.
Unintended Consequence of Technology: New LED traffic lights can't melt snow