From tonight’s 6pm news on GlobalTV:
Toronto, like lots of other cities, is installing LED traffic lights. They’re brighter, more reliable, and draw less power.
Unfortunately, less power means they emit less heat - so windblown snow builds up on the front of the lenses and makes the lights invisible. The old incandescent lamps were heated by those inefficient, environmentally unfriendly bulbs, which would melt any snow that built up.
More unforeseen consequences: when schools ban the sale of lollies and soft drinks, the students find ways around the ban. Which shouldn’t be even vaguely surprising.