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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.
I wonder if there is some other design factor that is causing this problem, beyond just the LED lights not putting out as much heat as incandescent ones. I live in Colorado and most of the traffic lights here (Denver area) now use LEDs. I don't believe I have ever encountered one that was clogged with snow or ice. Not to say it doesn't happen, but I wonder if the traffic lights here are simply designed differently (better covers/shielding, spacing, ?).
It seems like a simple solution would be a small heater incorporated into the LED lamp assembly that only turns on below a certain temperature. Better yet- perhaps a sensor could be used to detect if the lamp was covered, perhaps by reflectivity. This would probably still use a lot less electricity over the course of a year.
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.
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I was up in Fargo, ND visiting family for Christmas (yah shoor ya betcha) and a traffic light was out on a 6-lane intersection. Guess what? Everyone was calmly proceeding as if it was a 4-way stop. No drama, no retardation.
This whole thing is a non-problem. It's just that lazy journalists love it because it's "irony". It's not really ironic unless you're Alanis Morissette, but it makes for an easy, shitty space filler. Notice how in that story the SIGN is also covered in snow? ZOMG! We need heated road signs! Woe is me! Signs can sometimes become obscured by snow, the horror! The HORROR!
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.
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.
Building a new power plant will make electricity cheaper? I do not see that happening in the short term. Power plants are not cheap to build.
Now that the problem of sticky snow has been discovered the obvious solution is to add heaters to the traffic lights that can be turned on in winter. The minor extra cost of a heater just means the pay back on using LED's and saving electricity takes a few more months.
Having an SUV does not make it easier to drive in the snow. Having good snow tires does, having chains if required, and learning to drive in snow: no sudden movements, don't stop when going up hill, stay way back from the car in front, and slow down well before corners. Take your foot OFF the brake if skidding so you can steer.
We only get big snowfalls every 2 or 3 years so most drivers here are really bad at driving in snow. SUV's and 4 wheel drives make up 80% of vehicles in ditches due to the "over confidence factor". It seems many people with 4 wheel drives don't realize ALL cars have 4 wheel brakes.
Going green generally saves money, and makes your life easier.
Anarchists never rule
Red-green colorblindness should not affect the ability of a person to correctly observe a traffic light.
Under ideal conditions, you're correct. (But this whole article is about non-ideal conditions)
I have some color blindness and I can describe the problem I have. When it's raining and at night, it's difficult for me to tell a green light (non LED) from a nearby street illumination light (from a distance). I know that sounds crazy. Because it's dark, it's hard to see the rectangular enclosure, so I can't tell by the green-light's position. Only after it's changed to yellow then red can I tell which light was the illumination light and which was the green light.
And I can't just assume that lack of a yellow or red means I have the green, because it might be burned out.
The new LED lights use a different color of green that has a higher blue component that makes them completely obvious. Plus the LED lights are more intense than the other lights. This may be due to the light from an LED being a smaller set of frequencies (or a single one?) compared to a filtered incandescent, though I really don't know much about the physics of LEDs.
So, I expect it was mentioned in this context because when it's dark it's harder to tell the position of the green light against the dark enclosure, especially when there are nearby white lights. And the blue-green used makes them easier to see. At least that's my experience.