LED traffic lights don't melt snow and do cause accidents

A number of cold weather American states are reporting their dismay at finding out that LED traffic lights are so energy efficient that they do not produce enough excess heat to dissipate any snow that covers them. It turns out, perhaps in an homage to bad engineering everywhere, that the inefficiency of incandescent light bulbs was previously relied upon to keep traffic signals unimpeded. The new LEDs do not achieve the same effect, which has resulted in a few accidents and even a death being blamed on obstructed traffic lights. Feel free to apply palm to face now. It's not all gloomy, though, as the majority of people are said to treat a dysfunctional traffic light as a stop sign (how clever of them), and a tech fix is being worked on as we speak.

Engadget. Dec 17, 2009.