Speed Bumps

"Even the very wise cannot see all ends" - Gandalf the Grey

Sometimes with progress comes setback. For many many years, incandescent bulbs were used in traffic lights. They were inefficient, not very bright (hence the big sun shields on them), didn't last long, and were very difficult and dangerous to replace.

But with the incredible advances in Light Emitting Diode (LED) technology we have seen these past five years, it didn't take long to figure out that the savings of moving traffic lights to the new technology would be huge. While an LED light costs more to make than an incandescent bulb does, they last almost forever (incandescents last about a year, while the first LEDs installed ten years ago are still going strong and will probably last at least 25 years unless they are physically damaged), use far less power, and they're very durable to boot. Heck, the color is even more vibrant. Win-win situation, right?

Well, not entirely. And here's why...

Remember, LED lights are very efficient. What that means is, they use less electricity. More than 90% less. That's the definition of efficiency here: more light per unit of energy. LEDs convert more energy to light so less goes to waste heat, as compared to incandescents.

See the problem yet? LEDs don't get hot. And in the winter, in states with significant snowfall, this turns out to be a big problem. LED streetlights do not melt the snow off of themselves! This has apparently led to many accidents and at least one death is blamed on it.

You can do your best, but there always seems to be one eventuality that slips through your analysis. So the LED engineers are back to the proverbial drawing board, devising a fix for this problem: a system that acts like a rear-window defroster, only when needed, that will cost a little more energy in the winter but still nowhere near as much as the old lights gobble.

Another hiccup, but the inexorable march of progress continues...