The snowy weather across much of the northern hemisphere this week is being disruptive in many ways. At the Freakonomics blog, Eric Morris highlights one unanticipated and unintended disruption — snow obscuring energy-efficient LED traffic lights:
The biggest weakness of LEDs is their biggest strength – they don’t radiate much heat. What on earth could be wrong with that? Depends on which part of the earth you inhabit. In the upper Midwest, LEDs can have deadly consequences.
LEDs’ energy conservation creates a problem in case of a – literal – perfect storm. Low temperatures, wet snow, and driving wind can coat – and obscure – traffic signals. Traditional bulbs throw off heat which melts the snow. LEDs don’t. The result is intersections without visible traffic lights which are hazardous and sometimes deadly, as was recently the case in Chicago.
The principal tradeoff in this example is between energy efficiency/cost/environment and safety while driving. I hope that one of the commenters is correct and that there are straightforward engineering approaches to minimize this tradeoff. My initial thought was downward-slanted shields around each light, both to keep the snow off of the light directly and to take advantage of gravity to prevent the snow from accumulating on the fixture.