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Power Transportation

Midwest Seeing Red Over 'Green' Traffic Lights 839

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.
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Midwest Seeing Red Over 'Green' Traffic Lights

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  • by Carewolf ( 581105 ) on Wednesday December 30, 2009 @10:04AM (#30593546) Homepage

    What do you do if only part of the lights were covered, especially if the parts covered are extensions such as no left-turn? I know it is much to ask, but as minimum, maybe you should Read The Fucking Summary.

  • Re:Solvable. (Score:5, Informative)

    by YrWrstNtmr ( 564987 ) on Wednesday December 30, 2009 @10:04AM (#30593548)
    Oh, I thought the law was clear - when the signals are obscured or not working, stop at the intersection and then proceed as per a normal crossroads.

    In the Illinois case, the green arrow was obscured just enough to appear to be a full green.
  • Re:Simple (Score:4, Informative)

    by qoncept ( 599709 ) on Wednesday December 30, 2009 @10:07AM (#30593596) Homepage
    Genius. I would say RTFA, but you all you really need to do is read the summary.
  • by Anonymous Coward on Wednesday December 30, 2009 @10:15AM (#30593720)

    Not always. One light in particular is bass-ackwards [].

  • Re:Hmm... (Score:5, Informative)

    by CoreDump ( 1715 ) on Wednesday December 30, 2009 @10:25AM (#30593908) Homepage Journal

    The ones you see around Denver *are* designed differently.

    The shield around the lights is open on the top, so that it funnels wind downwards and blows the snow off of the light. The ones in Illinois are not. The Colorado shields cost ~$30.

    This isn't a case of LEDs being bad. Nor is it "greens run amuck". It's idiots run amuck.

    The driver of the truck should be prosecuted. In every light cluster with turn arrows, the turn arrows are on the bottom. They are NOT the solid green. And being from Illinois, in Driver's Ed we were all taught that Green does not mean 'Go'. It means *proceed when the intersection is clear*. So, failure on several points by the driver of the truck.

    Illinois needs to install the same snow shields that Colorado and other states have successfully done with their LED light installations.

    We'd probably have them already, except we spent all our DOT money on 'Rod R. Blagojevich - Governor' signs.

  • by ILuvRamen ( 1026668 ) on Wednesday December 30, 2009 @10:32AM (#30594008)
    I'm from Wisconsin and we got about a foot of snow twice and I did some driving. You can still see the signal lights just fine. Snow is made out of ice which makes it translucent and the colors come through perfectly. It sounds like, as usual, people are driving with their heads up their asses in the snow and making up some BS excuse about why they went straight through a red light. Don't believe a word of this.
  • Re:Hmm... (Score:2, Informative)

    by Dipster ( 830908 ) on Wednesday December 30, 2009 @10:33AM (#30594050)
    The higher elevation of Denver results in a drier snow that is less prone to sticking than in Illinois. We get more "slush" than snow...
  • by jmauro ( 32523 ) on Wednesday December 30, 2009 @10:36AM (#30594102)

    But in the horizontal configuration the red light is always on the left and the gree light is always on the right. Same rules apply.

  • by chaim79 ( 898507 ) on Wednesday December 30, 2009 @10:38AM (#30594122) Homepage

    I'm guessing you haven't experienced driving sleet or a blizzard or any other midwest-style winter weather, when the wind gets blowing it will pack snow anywhere and everywhere.

  • Re:Solvable. (Score:3, Informative)

    by glueball ( 232492 ) on Wednesday December 30, 2009 @10:39AM (#30594136)

    I am in Wisconsin and saw the partially obscured arrows. It did look like a full green. I knew the intersection, slowed down and could yield. The people who are unfamiliar with the intersection might never have realized it.

    Obscured is a misleading description. Better description is "diffused" kind of like a quarter moon behind thin clouds still can look full.


  • by Moryath ( 553296 ) on Wednesday December 30, 2009 @10:45AM (#30594250)

    That doesn't help with snow-related icing, because snow doesn't "fall" like rain (more surface area, less density and so it's much more susceptible to slight wind gusts in any direction). Generally, it doesn't even "stick" in place unless you have either a barely-frozen "wet" snow in just-barely-freezing temps, or a surface with "just enough" heat to get the initial under-ice layer going.

    There's plenty enough ambient blowing during a good snowstorm, and these LED's are putting out "just enough" heat that the first few snowflakes go through a slight partial melt and stick themselves on good and tight. Chicago Tribune has a great photo showing you what happened [] to the "blinders with no bottom" approach. Even if you squared off the hoods, you'd still have this issue.

  • by omnichad ( 1198475 ) on Wednesday December 30, 2009 @11:23AM (#30594980) Homepage

    I live in the midwest. Snow isn't just snow 99% of the time. If the snow starts to melt on the way down, you get a very wet snow that packs tighter than light powder does. Sometimes you get tiny frozen flakes that don't stick to each other, and others, they clump together into giant snowflakes. Freezing rain doesn't have flakes. So it's pretty easy to tell the difference.

  • by necro81 ( 917438 ) on Wednesday December 30, 2009 @11:33AM (#30595166) Journal
    I've lived in the Midwest, in New England, on the great lakes, climbed lots of mountains, and even spent time on the Greenland ice sheet. There's all manner of snow in this world, and it is possible, even easy, for snow to stick to "perfectly smooth and sealed and vaguely concave" surfaces. Ever had snow adhere to the sides of your car? Think de-icing planes is just a fun way to kill time on the tarmac? Snow and ice are able to adhere and build up onto just about every surface, in any orientation, under some set of naturally occurring conditions. There are things you can do to make it harder for that to happen, but it's impossible to prevent fully.
  • by Brett Buck ( 811747 ) on Wednesday December 30, 2009 @11:39AM (#30595300)

    idiot driver should be prosecuted since everyone knows the third light from the top is regular green and not a turn signal.

          Bullshit! I would wager at least 25% of the LED lights I have seen have the third light as a combined left turn or straight green. LEDs permit that easily - just turn on the elements for the left turn, then all of them, when it goes from "left" to "green".


  • by Minwee ( 522556 ) <> on Wednesday December 30, 2009 @11:43AM (#30595378) Homepage

    If the covered side treats it as a 4 way stop, the oncoming 'Green' lane will not stop (they have no way of telling that the other side is covered) so there exists a possibility of someone pulling out into the street on a Red light, and getting hit...

    I believe that that sort of situation is adequately covered by this brief instructional video on the subject of driver training manuals [].

    Assuming that all cars are being driving by competent drivers who should be allowed behind the wheel of anything more dangerous than Mario Kart, how is it possible that one of them will see that the light is obscured, correctly treat the intersection as if it were a all-way stop, stop his or her vehicle, look around to see that the intersection is clear and then proceed through only when it is safe, only to be hit by an oncoming vehicle? Unless the vehicle in the oncoming 'Green' lane is either invisible or travelling at something close to the speed of light that can't happen unless one of the drivers has skipped an important step.

    And in that case I'm going to have to let Robert Loggia explain where things started to go wrong.

  • Re:Hmm... (Score:3, Informative)

    by Dipster ( 830908 ) on Wednesday December 30, 2009 @11:47AM (#30595478)
    The lower atmospheric pressure in Denver means that the air holds less water vapor at the same temperature. The water vapor in the atmosphere condenses on the snowflakes as they fall. If the temperature is relatively close to melting point, the condensation on the snow flakes will not freeze completely and result in a "wet" snow. Since there is more water vapor in the Illinois air versus the Denver air at a given temperature, the effect is more pronounced in Illinois.
  • by nsayer ( 86181 ) <nsayer&kfu,com> on Wednesday December 30, 2009 @12:18PM (#30596086) Homepage

    Come on, a thermister set for 32 degrees F and a 5 watt resistor would probably do the trick. How much could that really cost extra?

  • by Le Marteau ( 206396 ) on Wednesday December 30, 2009 @01:09PM (#30596958) Journal

    > The Inuits (you know, the guys whom entire daily universe is either Snow or Ice...) have over a hundred words just for snow.

    Not really. That's an urban legend.

    See []

    and []

  • by ubrgeek ( 679399 ) on Wednesday December 30, 2009 @02:19PM (#30598050)
    I'm colorblind and I did learn that. But in some places in Southern California (for example), the traffic lights are hung sideways. Maybe it's for aesthetic reasons, but it makes it tough to figure out yellow vs. red on the fly. For me, another issue is the flashing yellow lights at intersections. Or is it a red light? Or a yellow light? Or ... Depending on the ambient light, the current bulb lights (I'm guessing they're bulbs?) aren't distinct enough for me to be always able to tell and so I sometimes just come to a complete stop (which tends to piss off the people behind me.)
  • by metlin ( 258108 ) on Wednesday December 30, 2009 @02:21PM (#30598090) Journal

    Well, in New England, they actually have those big red lights on top that flash when the other lights are coated with snow.

    Basically, if the weather is bad, then all intersections turn into 4-way stops and those lights take over. I'm surprised that that's not more common.

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