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Midwest Seeing Red Over 'Green' Traffic Lights
theodp writes "Many municipalities have switched to LED traffic signals because they burn brighter, last longer and use 90% less energy than incandescent bulbs. But they also emit less heat, meaning they sometimes have trouble melting snow, causing problems across the Midwest. In Wisconsin, snow blanketed LED traffic lights in some towns, leading to crashes at intersections where drivers weren't sure whether to stop or go. The unintended consequences of the green technology were also identified as a 'contributing factor' in the death of an Illinois woman hit by a driver who blamed the snow-covered energy-efficient signal for giving the appearance of a normal green light instead of a left-turn signal. 'We can remove the snow with heat, but the cost of doing that in terms of energy use has not brought any enthusiasm from cities and states that buy these signals,' said the CEO of an LED traffic-signal manufacturer. 'They'd like to be able to take away this issue, but they don't want to spend the money and lose the savings.' In the meantime, some towns are addressing sporadic problems by dispatching crews to remove snow or ice from signals using poles, brooms, and heating devices." We were discussing these recently at the office — several folks in the building are red/green color blind and different street lights are differently distinguishable.
I read this and I almost immediately thought "propaganda." Why? A appeal to fear based on a insignificant and easily fixable event, then attempting to tie the fear to larger political concepts. Fear change! Fear green! Equals death! Keep same! Same is warm! Same is reliable! Same is safe! You don't have to think about same!
Any sufficiently advanced influence is indistinguishable from control.
Don't blame the installers. Based on my experience, I would wager 100 bucks it was a voted in politician that made the decision, against the recommendations of professionals.
The Kruger Dunning explains most post on
It isn't just about energy costs(though those are a significant factor). Incandescent bulbs, even the ones that trade off efficiency for durability, have crap lifespan. Estimates vary somewhat(depending on local labor costs/municipal contracting efficiency, and chosen relamping interval); but $50 per bulb replacement, with bulbs replaced annually, seems to be a common enough number. By comparison, reasonably engineered LED modules are supposed to give you a decade without replacement. Even if energy were free, there'd be a good case to be made.
As it is, this seems to be a story (depending on whether the fuckup occurred on the engineering side or the buying side) either of shortsighted buyers opting for false economies, or lazy engineers failing to think through likely failure modes.
Electrical heating of transparent enclosures(either by a resistive film applied directly to the enclosure surface, or just a heater inside the enclosure) is not exactly rocket surgery. We've been doing it for decades in car windows, among other places. Nor is measuring the opacity of a given surface all that difficult. There are a number of robust approaches you could employ(optointerrupters around the rim testing for interruptions caused by material on the lens, photosensors scattered in the LED matrix, measuring intensity of light reflected back to the emitter array, etc.) These would modestly increase emitter and energy costs; but would easily eliminate the problem, and still come in cheaper than the incandescents.