LED Astray

Technological innovation has cut many of the trickiest environmental Gordian knots. As readers of SuperFreakonomics know, at the end of the 19th century the American city was tottering on the brink of environmental catastrophe. The cause: byproducts of transportation, specifically the horse-drawn variety (more here). Manure, flies, accidents and disease abounded, until the timely arrival of a technology which at the time was hailed as an environmental savior — the internal combustion automobile.

Of course, those who celebrated did not fully realize that the miracle technology would bring troublesome consequences of its own. Today we face the specter of global warming, to which the automobile is an important contributor.

Just like our ancestors in the fin-de-siecle city, we are using new technology to fight the shortcomings of the old. And unsurprisingly, like our ancestors, we are bound to find that our technological fixes can have unintended, malign consequences of their own.

Consider the seemingly noncontroversial replacement of conventional traffic signals with LED bulbs. What’s not to like?

LEDs last up to ten times longer than the old bulbs, saving on equipment and labor costs. They drastically cut energy consumption. (One Illinois jurisdiction found that the conversion of an intersection reduced electricity bills from over $60 per month to under $10.) Finally, LEDs are brighter than conventional bulbs, increasing visibility. Pretty cool, huh? Exactly – and that’s the problem.

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.

None of the proposed solutions are foolproof. Heating up the LEDs would help defeat the purpose of saving energy. Lights can be cleaned manually, but with about 2900 traffic signals in Chicago alone, finding, dispatching teams to, and cleaning obscured lights is a fairly big task.

We shouldn’t overstate this problem. It takes just the right conditions to occlude lights, and many times the situation resolves itself. When lights are out, motorists should know to exercise caution and treat them as if they are stop signs.

However, to this point dozens of accidents have been attributed to the LEDs. Is it worth it? Probably, but that is little consolation for those hurt and killed in these crashes.

Perhaps new technological solutions will be found, as has happened to an extent with the automobile. In the mean time, hopefully motorists in colder regions will lengthen their lives by adjusting to this new hazard. Or by moving from Chicago to LA, the way I did.

(They’d have to give up real Chicago dogs and pizza, but this would undoubtedly lengthen their lives as well. Whether a life without these delicacies is worth lengthening is another question.)

Despite the crashes, departments of transportation have no intention of giving up LEDs, any more than their 19th century counterparts would have considered giving up the internal combustion engine. As with the auto, some consequences, even deadly ones, will have to be lived with.

This may seem callous, but transportation often calls for tough decisions that involve sacrificing human life. Surprisingly, these often receive very little public scrutiny compared to more conspicuous life-and-death issues like the death penalty or the wars in Iraq and Afghanistan. More on one such overlooked transportation question coming soon.

(Hat tip: Gary LaBelle)