Going Green…And Causing Accidents

I ran across an old news story yesterday, and I decided I had to comment on it, because it is a great example of what happens when people rush to “go green” without thinking of the consequences.

The story reports on several communities that have changed the incandescent light bulbs in their traffic lights to LED lights. The LED lights produce a lot of light without producing much heat. Thus, for the same light output, they don’t use nearly as much energy. As a result, they cost less to run, and they are promoted as a green alternative to the old-style incandescent traffic lights.

Of course…there is only one problem. In snowy conditions, these LED traffic lights are responsible for causing traffic accidents and, according to the news story, at least one death. Why? Specifically because they don’t produce much heat. When it snows, the snow can cover up the lights on a traffic light. However, since the old-style incandescent lights produce a lot of heat, they melt the snow. That way, the snow doesn’t cover up the traffic lights. The LED lights don’t produce much heat, so the snow doesn’t melt. Instead, it covers up the light, making it impossible to see whether the traffic light is telling you to stop or go.

What’s to be done about this? According to Lt. Jim Runge of the Green Bay, Wisconsin police:

as far as I’m aware, all that can be done is to have crews clean off the snow by hand…It’s a bit labor-intensive.

Now the article says that Wisconsin saves a LOT of money by putting in the LED lights, and even though they have to hire crews to clean them off during snowstorms, there is still a net savings. That might be true, but I would have to see the actual numbers to be certain. Also, if you add in all the carbon dioxide emissions required to take crews from traffic light to traffic light in order to clean them all, it is not clear that this is reducing Wisconsin’s “carbon footprint.”

Of course, even if there is a net savings in both cost and emissions for Wisconsin, it is done at the expense of people’s safety. I expect some “environmentalists” have no problem with that. However, this environmentalist thinks that people are a part of the environment, and they should be protected as well.


  1. Josiah says:

    Do I detect Mr Wile that you are being somewhat irresponsibly biased in your response?

    Sitting in Tete where the temperature is about 35 degrees Centigrade, it would be foolish were I particularly bothered about snow.

    I am concerned that:
    During a heavy rainstorm here it can be litterally impossible to see your own hand in front of your face. A brighter traffic light would I’m sure be a welcome blessing. Granted tropical storms may not be a feature of Wisconsin, but there will be at least one condition which limmits visibility, mitigated by the brighter LEDs.

    A longer lasting bulb must make it significantly less likely that a bulb will be out (which makes it sort of hard to see when it’s on! and equally needs a work crew to come along and fix)

    Cheaper opperating traffic lights might convince somebody that they could put a few more of them in, or the saving should be used in another public benefit area, possibly saving lives.

    So even if you decline to consider the option that the lights may be redesigned precisely to accomodate the emerging LEDs (Install a activatible heating coil, Put a hat on them, etc) I can see from third world perspective a few neglected merits to the system, and I’m sure your ignoring some as well.

    1. jlwile says:

      Obviously I am not discussing the third world here. I am discussing what is happening in the snowy regions of the US. I can imagine areas in which LED lights would be very good – including parts of the US that rarely get snow. My point is that the snow thing was obviously not thought of at all before these cities rushed to “go green,” and now public safety suffers.

      Your idea of putting heating coils on the lights is a really good one.

  2. Kyle says:

    Wow, interesting post, but Josiah’s got some really good points. I wonder if it can provide that much extra light to make a difference, though.

    1. jlwile says:

      Kyle, the LED lights are definitely brighter. That is one of their advantages.

  3. Ben Michael Fournier says:

    LEDs do have a lot of technical superiority in comparison to incandescent bulbs, but during winter if the lack of heat production is aiding or causing traffic accidents, then that increases the chance of human fatality and injury. Which is more important, saving a few bucks or saving a few lives?

    An alternative to having crews clean them is to have a light intensity circuit or other sensor system determine if the bulb is being obstructed, and when exterior light intensity reaches a threshold have a heating circuit activated and deactivate either on a timer or when the threshold is past again from the opposite direction.

  4. Josiah says:

    Ben, your premise in the first paragraph is flawed. Consider the case of a health service that can provide one hugely complicated life saving procedure or 3000 equally important blood transfusions. Is the life in the first case worth the “few bucks”? Yes. But is it worth the 3000 lives which could not be paid for? I suppose not. According to the linked article there had been one death as a result of snowed traffic lights. Is fitting every set of lights with heater coils and ciruitry the most efficient way to save human life?

    To match yours, another alternative is to cut with the high tech, and redesign traffic signals. For example have a bar which goes up for go and down for stop. Being covered in snow has no effect. Teaching people what it means could be challenging though.

  5. Ben Michael Fournier says:

    Perhaps a light intensity sensor system wouldn’t be best, as it would get false readings from the presence of the light. But in general a sensor based heating system could be developed if desired. I don’t know how much wattage usage it would have in comparison to having incandescent bulbs alone would be though. Could be more or less wattage used in operation, but it would add additional layers of complexity for repairs, which would increase repair time.

  6. Ben Michael Fournier says:

    Josiah, would a motor and gearbox system use less wattage or have less complexity than an incandescent lightbulb to repair or be as cost effective to replace?

  7. Josiah says:

    Measuring heat wouldn’t work. You could only measure the ambient temperature, which means you’d end up heating street lamps on cold days regardless of whether or not it was snowing (which is fairly rare) and whether the snow was sticking (which is a small fraction even of snowy days).

    A pressure sensor might do it, if the mass of snow needed to obstruct the light is significant. A simple push-to-make switch, balanced by a spring has the advantage of doing nothing while the circuit is off.

    As to my own alternative I haven’t really thought it out, but given that the bar balanced itself around the fulcrum and only moved (under a motor or just an electromagnet) it might be designed to use less power. I can’t be bothered to do the math.

  8. Josiah says:

    I’m sure my points all work equally well in Northern USA, if not better. I deliberately neglected my fourth point, that it would be far easier to install a power backup for LED based lights (a problem more regular here than sticky snow up there) because I’ve been led to believe that biweekly or more regular power cuts don’t happen there.

    I agree that the snow side effect probably wasn’t considered beforehand. However there must also emerge beneficial side effects that haven’t been considered. You take a handful of accidents which did happen as a result of snow, but not knowing what would have happend can only ignore safe journeys which would otherwise have ended in disaster.

    Seeing a brighter red light through the mist could easily have prevented an exact replica of the single fatality recorded in your article, if the weather were that way inclined. The same can be said for my other two arguments and countless more.

    Therefore I’d say jumping to the conclusion that public safety has suffered is surprisingly poor science coming from you.

    1. jlwile says:

      Josiah, I have to rely on the known facts. You can make up all sorts of hypothetical scenarios if you want, but we can find several accidents and one death that are the direct result of LED traffic lights. Those KNOWN problems are more important than a host of POSSIBLE benefits. That’s the way a scientist would look at it, anyway.

  9. Josiah says:

    So if somebody built a hydroelectric dam to supply their region’s power needs and three people fell in and drowned, would you conclude that hydroelectricity is bad for people’s health? And you would have to make that judgement without considering the hundreds if not thousands of people saved chronic respiration problems and other issues associated with the coal power that existed before? Of course it isn’t very easy to count the number of people who didn’t die as a result of a change (neither other places nor other times being suitible control cases). And of course when you have a single death you have a tragedy to recount instead of numbers.

    1. jlwile says:

      Josiah, I would not say that hydroelectric power is bad for people’s health if some people died because of the CONSTRUCTION of the dam. However, if the REGULAR OPERATION of the dam continued to kill people, it would be bad for people’s health. It’s the regular operation of LED traffic lights that is causing accidents. Clearly, then, the LED traffic lights are endangering people.

      You are certainly correct that in determining the overall endangerment of people, one must consider the lives saved against the lives lost. But in this case, there is no evidence for lives saved. There is only evidence for lives lost. Thus, the obvious conclusion is that these traffic lights endanger people.

  10. Josiah says:

    I would ask how you presume to scientifically count lives avoided by LED lights (or Hydroelectric power, vaccines, etc) for counting against the deaths. I have mentioned a few of the dangers that are avoided by LED lights, and as those very real dangers exist, lives will be saved by avoiding them. You can’t assume that lives aren’t saved because you fail to distingush these few from the thousands of cars that pass by traffic lights every moment. Therefore you cannot defend your condemnation of LED lights, though your condemnation of alarmist response without considering the results certainly still stands.

    1. jlwile says:

      Josiah, counting such lives are easy. For example, you could do studies of accidents in cities that do have LED traffic lights versus cities that don’t have such lights. Then, you could test your hypotheses by looking at specific days when you think LED lights would be beneficial (such as stormy days, foggy days, etc.). If you see that those days produce a trend significantly different from other days, you would be able to count the accidents saved by LED lights. This is exactly what is done with vaccinations, for example. We look at vaccinated people versus unvaccinated people and compare the rates of disease. When the decrease in disease rate is significantly beneficial compared to any severe side effects, the vaccination becomes part of the standard schedule. If the decrease in disease rate is NOT beneficial compared to the side effects (which was the case for the old rotavirus vaccine), the vaccine is not a part of the vaccination schedule.

      You can’t assume that the known accidents are outweighed by hypothetical scenarios under which accidents are avoided. That is clearly unscientific. You have to look at what is known. Unless studies such as the one I described are done, the most scientifically reasonable thing to conclude is that LED lights are endangering public safety.

  11. Josiah says:

    With that I agree. However in the absence of known cases in which lives are saved you cannot assume that they do not exist. A single death and a handful of accidents is statistically insignificant among the many kinds of road tragedies that occur, and most likely would not be noticible in exactly that kind of study (if LED lights in a SNOW FREE area saved exactly one accident, I am certain you would attribute it to random variation).

    I do not dispute that the accidents mentioned do result from a switch to LED lights, but I do think it is your manner which is worryingly unscientific. You are condemning the new as dangerous based on a few accidents and a single death WITHOUT looking at the same sort of numbers you say would be needed. It’s like picking the handful of children who react badly to cow pox and deciding that the smallpox vaccine isn’t worth it–no studies involved. Surely you cannot say that this is the scientific way to go about things!

    1. jlwile says:

      Without any data to support the idea that lives are saved by LED lights, it is scientifically irresponsible to assume they are.

      You are certainly incorrect to say, “A single death and a handful of accidents is statistically insignificant among the many kinds of road tragedies that occur, and most likely would not be noticible in exactly that kind of study.” Given the fact that DOZENS of accidents have been directly attributed to LED traffic lights on snowy days without the need for studies, a study would definitely see them, as a study is much more precise.

      Your analogy to the smallpox vaccine is not accurate. In the smallpox era, there was no need for studies to observe the benefits of smallpox. Indeed, people STOLE the vaccines from hospitals long before any serious studies were done, because they OBSERVED the benefits. Thus, with the smallpox vaccine, there were OBSERVED benefits that outweighed the OBSERVED side effects. Thus, the scientific conclusion was that the smallpox vaccine is good. In this case, we have OBSERVED accidents caused by LED traffic lights, and NO OBSERVED benefits. Thus, the scientific conclusion is that the traffic lights are bad for public safety.

  12. Josiah says:

    The problem is that you CAN observe without a study your handful of actual accidents but it is not possible among the thousands of safe journeys to observe that a few dozen would have been accidents or evan fatalities.

    Now it takes a massive and obvious saving to realize that something avoids a problem, however serious, while only a few to cause the general public to see that it may cause a problem. In the absence of a comprehensive study the result of first impressions will be biased against the change. It will be so significantly biased that your result must be unscientific. I do not presume to say that there are definite savings in lives in LED lights, but to show a few advantages that COULD and SHOULD save lives, and would make a study necessary before you condemn them one way or another.

    1. jlwile says:

      Josiah, you are not correct on that point at all. If LED lights produced fewer accidents, it would be observed. After all, communities keep track of accidents. Much like the obvious observation (which required no study) that vaccinations caused people to avoid getting sick, if LED lights really were helping people avoid accidents, it would probably be observed.

      The bottom line here is that there are KNOWN accidents caused by them. There are only HYPOTHETICAL ways in which they MIGHT cause accidents to be avoided. Thus, the most reasonable scientific conclusion is that they endanger public safety. Now, of course, if new data come to light, I could easily change my view. That’s what scientists do. Without any new data, however, the scientific conclusion is obvious.

  13. Josiah says:

    Let us assume that harmful human-related climate change does not exist, hence removing the potential billions of lives saved from erratic climates by measures such as these. Even within that assumption I maintain that there will be lives saved, perhaps related to the advantages I outlined, as a direct result of changing to LED traffic lights.

    You say that communities keep track of traffic accidents, including their causes, and with that I have no dispute. You would say however that because of this they would notice a safety benefit in LED lights. Here I disagree. Neither are psychologists, but we both know that is not how the human mind works.

    There are many many times more safe passages through traffic lights than there are accidents at the intersections. An accident is a tragic and noticible event. It attacts attention. A single death can reach the news.

    However a car that gets through a junction is a non-event, it will won’t even cross the mind of the passengers that they could have died just then. If an accident would have occured but didn’t, it still didn’t, and no newspaper or website will report “Today on such and such a street, Jo Bloggs didn’t die because his car didn’t crash because of the brand new LED lights!” Nor in fact would anyone think “We couldn’t build this hospital if it weren’t for the $750,000 saved from energy efficient traffic lights.”

    Therefore like you the people who track accidents in their community would exclaim at the death resulting directly from the new lights, but miss the lives saved as a result of the same. Surely this cannot be scientific.

    1. jlwile says:

      Josiah, what you are missing is the fact that residents notice the number of traffic accidents in their area. For example, my mother used to sit on the city council. She (along with the other council members) would have to approve whether or not traffic lights, stop signs, etc. were put up at intersections. The council would often hear testimony from people who would tell them how they noticed a huge drop in accidents after a traffic light or stop sign was installed at an intersection. Thus, it would be very easy for a community to see if LED traffic lights avoided accidents – they would observe a drop in the number of accidents after LED traffic lights were installed.

      In reference to the climate change issue, it is not clear that the LED traffic lights are helping that, either. I am all for reducing carbon dioxide emissions, as long as it doesn’t endanger lives. Regardless of whether human-induced climate change is real, it is never a good idea to put waste products into the air. However, based on what has to be done to keep LED traffic lights from causing more snow-related accidents, it is not clear that the overall energy consumption for a community that has a reasonable amount of snow is lower once LED traffic lights have been installed. After all, transporting work crews and blowing snow off lights takes energy, and that results in carbon dioxide emissions.

  14. Josiah says:

    I didn’t question with the intention of discussing the effect of LED lights on Climate change.

    Rather I belive your condemnation of them for the small number of accidents throughout the Northern States against such possible benefits is not well founded. This time it is your analogy that is flawed, because the purpose of Traffic lights or stop signs is to prevent accidents. For this reason I would anticipate a significant placebo effect on those who testified. At the same time the addition of a set of traffic lights at a busy intersection would provide a significant safety benefit. As you say, “they noticed a huge drop in accidents”.

    In this case however the PUBLISHED benefits are energy and money efficiency, not safety. There is no placebo effect. The numbers involved will be far smaller. And there are event stories such as this one which far outweigh numeric safety gains in the human mind, as I mentioned earlier. I would expect people to notice a safety gain in installing lights, but not in switching from the incandescent version. But of course failing to notice something does not in any way affect its existance.

    1. jlwile says:

      Josiah, you are certainly wrong about the placebo effect with stop signs and traffic lights, as such testimonies were easily confirmed by police records. The point is that studies have not been done on EITHER the accidents caused by LED traffic lights OR the accidents avoided by them. However, both are easily observable, and the observations indicate accidents caused by an no accidents avoided by. Thus, the proper scientific conclusion is that they are endangering lives.

      I certainly agree that failing to notice something doesn’t mean it isn’t there, but the more noticeable something is, the more prevalent it is as well.

  15. Josiah says:

    Dr. Wile, there was certainly something of a placebo effect in that people expected the change, and therefore noticed it. Pure placebo in medical terms may be for example a sugar pill, but positive expectations will have positive consequences in addition to any real change–one would not dare to think that while a sugar pill may make one FEEL better from an infection, appropriate medication cannot!

    Fair enough, once you bring police records onto the scene you have valid statistical data to base your conclusion on. Nonetheless those initial observations of a change (i.e. adding lights) would be far more likely to be taken due to the scale of the benefit and the expectation of an improvement.

    In this case there is no such expectation that the shift may have safety benefits outside of climate chage (which people don’t expect to observe). If there is an improvement in the level of safety, people don’t expect it.

    It is generally far easier to spot an event that occured than an event that was averted, and therefore in the absence of a study you would expect small negative safety changes to be far more noticible than positive safety changes, even if the latter were larger.

    To reitierate, an accident directly resulting from snow on the lights catches the human eye. None of the other cars that crossed the same set of lights safely are noticed. None of the cars that passed safely during a storm were noticed. If ten of those might otherwise have crashed, no-one will notice. If lives are saved in projects funded from the 750,000 dollars a year, the original saving will not be noticed (nor the lives lost that might have been saved in such projects, had the money not been spent on heating coils).

    Observation is biased toward the condemnation of LED lights. You admit that there has been no structured study regarding either. Any judgement based merely casual, observations which ignores a known bias cannot be called just, nor even scientific.

    Instead you demonstrate a similar sort of falacy to that in which you consider scathing consumer product reviews equal to commendations of the same product. The single person whose toaster blows a fuse as soon as it’s plugged in notices and complains. A two thousand people whose toasters toast to perfection sit down and enjoy their breakfast; only two bother to post a review. This is another case of the event being OBSERVED while the non-event is overlooked. A statistical study would say that about point zero five percent of toasters are defective, looking at observations would place the value at one in three.

    1. jlwile says:

      Josiah, you really aren’t getting this, are you? You are simply incorrect that people don’t notice a reduction in accidents. They certainly do. There is no placebo effect, as the observations agree with police records. In the end people recognize both a reduction and an increase in accidents, as accidents directly affect their daily lives. More accidents cause them more problems, and fewer accidents cause them fewer problems. Using the same methods of observation, people see an increase in accidents with LED traffic lights and no decrease.

      Since people’s observations of reduced traffic accidents and increased traffic accidents have been shown to correlate with actual traffic records, we know that there is no inherent bias. Thus, the scientific conclusion is obvious. Now…as I have said before, if someone can produce studies that indicate a significant reduction in traffic accidents as a result of LED traffic lights, I am willing to change my mind. However, all current data indicate LED traffic lights are endangering safety, so a scientist must come to that conclusion.

  16. Josiah says:

    I will acknowledge that people notice both, but they will be far more likely to notice extra accidents and more likely to attribute them to the correct cause. At the same time the news is far more likely to advertise accidents resulting from a change than gains in safety.

    You don’t even have any evidence that anybody is noticing an increase in the number of accidents, rather that they are noticing a few specific accidents whose circumstanced depend on LED lights. Which is exactly my point–you cannot expect anyone to notice a few specific accidents that have been averted.

    1. jlwile says:

      You are certainly correct that it is POSSIBLE that no one is noticing the decrease in accidents, but based on what we know, the conclusion that the LED traffic lights are endangering public safety is the most scientific conclusion to reach based on the data we have. Once again, I will change my mind if more data come to light.

    1. jlwile says:

      Josiah, nice work! The third link seems to just be a sales link. However, the others are good. I think the best think mentioned was, “In some cases, LEDs save more than money. When incandescent bulbs burn out, they go out completely, without warning. On the other hand, LEDs often go out in parts, leaving part of the string of LEDs inside the traffic light operative and emitting light. Drivers then alert the authorities, who send out a crew to replace the failing light.”

  17. Josiah says:

    Thank you. That section was probably my favourite too, basically because it hadn’t occured to me as an advantage.

    I threw the battery backup sales page in because I reckoned if it were comercially viable, it had to save lives. Given that your far better at such debates than I, would you consider that bad practice then?

    1. jlwile says:

      I think the issue with debates is experience. You are actually an excellent debater for your current experience and education. In general, it is best not to detract from your point. I understand the desire to throw in as much information as possible, but if the point of the information is not clear, it tends to detract. Thus, I wouldn’t have put that link in, but that’s just me.

  18. Josiah says:

    Thank you for the advice.

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