Apparently, the new energy-efficient LED traffic lights proved to be fatal in snowy areas as they don’t have enough to melt snow, making the traffic lights un-usable.
…unlike conventional incandescent traffic lights, they do not generate enough heat to keep themselves clear of snow, and thus can easily become obscured by it. I don’t think anyone’s saying LED traffic lights are a bad idea in general, but it is an interesting parable about thinking all the way through a problem from a design perspective.
I have to agree, that’s something even I didn’t think of since I live in sunny California. Perhaps the traffic light designers have to more cautious about temperatures and how that can affect their designs.