LED traffic lights may use a fraction of the energy their incandescent predecessors used, but there's a problem emerging as we enter these colder months: LED bulbs don't give off a substantial amount of heat. When things got cold in the "good ol' days," incandescent traffic signals generated enough waste heat to melt any snow buildup. With LED bulbs, that snow just piles up until drivers can't see the signals anymore. You don't need to be Thomas Edison to imagine why this is a problem.
To a Luddite, maybe this means incadescent bulbs are the way to go. To the innovator, however, it's a sign that LED traffic lights still have ways to go, and the technology needs to improve to protect the lights in colder climes. Right now, however, they are proving to be a pain.
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. Until a fix arrives, it is best to take the advice of Dave Hansen, a traffic engineer with the Green Bay Department of Public Works. Treat a blocked signal as if the power is out. "If there's any question, you err on the side of caution," says Hansen.