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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.
Oh that's right... we do! If you get to an intersection and the light isn't working or isn't visible, you treat it like a four-way stop.
idiot driver should be prosecuted since everyone knows the third light from the top is regular green and not a turn signal. i've seen intersections with broken lights before and people are very careful when they go and make sure the other guy is going to yield.
some people are always in a constant state of hurry and can't seem to wait a few seconds
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
If you're not sure to stop or go, the answer is "stop". I can understand if it's dark and you don't see the traffic lights because they're covered with snow, but if the lights at the intersection aren't working, that doesn't mean the light is green. It means stop and go when it's safe to.
why don't they just angle the lenses downwards with less of a hood? problem solved.
Put a small heater in the traffic signal that turns on below 0C (32F). Problem solved.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Maybe the lights need to take on a new form? What kind of problems would arise from coating each LED's sides with black paint (to replicate the duty of the indirect sun shades) and spacing the LEDs out so snow can pass through them? Or possibly shaping the LED or a cover as a cone shape so that it's harder to cover with snow?
Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
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.
"I've never seen one obstructed by snow."
Yea, because you couldn't see it.
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.
Red/Green colorblindness is nothing new; that's why the lights are standardized to have green at the bottom and red at the top. If you can't distinguish red from green, you can at least distinguish top from bottom. Why is that not a perfectly acceptable solution?
You see? You see? Your stupid minds! Stupid! Stupid!
An article said changing to LED lights in an intersection brought about 100$ a month economy in electricity costs, for that particular intersection.
It would cost several hundred dollars to make changes to the semaphores (like changing the regular glass to glass with wire inside that would heat it and have sensors that would turn on the heating elements only when needed). Some towns only get that heavy snow once every few years or for just a few days each winter so when you think about it, it's cheaper to just send people with brooms to clean them when needed. If drivers would have more common sense and be more careful, there wouldn't be any accidents.
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.
Why would the heaters have to use much energy? It sounds like they're not needed very often. You could automatically trigger them via external light/temperature sensors with some minimal processing or modify the red light camera software to trigger them. The only real downside is massively increasing the complexity of what is currently a very simple device.
A simpler answer might be to train people that they actually need to slow down if a traffic signal is not fully visible.
My town mistakenly ordered IED lights. These remove their own snow.
If Slashdot were chemistry it would look like this:Cadaverine
the shroud is there to prevent mistakenly thinking you have green when the lane going in a different direction has the green. The top/bottom of those is utterly useless, though. The whole thing should be a flat surface aside from the blinders on the side.
and yet...
1) that sign is still completely covered and unreadable due to snow
2) No solution is offered for the sign
3) Nobody even mentions the sign. Without the information from the sign, people are expected to just practice safe driving.
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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.
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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.
True, but I don't think this was nearly as much about "going green" as it was "saving green". Local govt. all over the country has been proving time and time again that their *true* primary goal revolves around generating revenue and cutting costs, vs. motorist safety. Look at all the red light cameras they've been installing. Studies keep showing they cause MORE rear-end collisions, and they certainly create a number of legal and ethical questions. (EG. Most police departments have an internal policy or "code of ethics" stating they will keep private business out of their revenue collection process - yet they hire private contractors to both install AND run the red light cameras, with them getting a lion's share of the "cut" of each ticket that's paid!) But they really like the big boost to their bottom line they create, so screw the detractors!
And in this case, you see the same behavior.... Problem identified with new LED traffic signals and snow, but obvious solutions SLOW to be implemented, because it negatively impacts their cost-savings potential.
I live in North Dakota, we've had these LED traffic lights for years, and I cannot remember the last time I saw one totally snowed up. The shields that curve over the top of the traffic lights here do an adequate job of keeping the snow from coating the signals - including during the 3-day blizzard we had last week (I had to drive in it each of those 3 days, so trust me - they worked).
If they're not working in other states, than either their storms are somehow worse than ND's, or they've cheaped out on the snow shields that go over the top of the lights. I know which one I'd put my money on...
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.
Yes, it's true: if a traffic signal is obscured by snow, treat it like an all-way stop. I live in Florida, so all we have are blacked-out traffic signals during power failures.
But there's a danger:
Fast north winds mean the southbound signals are covered with snow, but the other directions' signals are visible.
You're driving south, your signal is covered with snow, and you are unaware that you have a red light. You come to a complete stop, treat it like an all-way stop, and keep going through the intersection. The cross street has a green light, and it's crash time.
This is also possible if the right lights burn out in the wrong combination. LED traffic signals are more reliable in this matter, so there's a safety improvement right there.
As for snow and ice melting, I assume that outfitting LED signals with heating devices thermostatically set to 36F is a LOT cheaper than switching back to incandescant beacuse of this "advantage". Even if you live in the coldest climate, you're still better off with fluorescent lighting at home, since incandescent lights are wasteful lights AND wasteful heat sources.
Here in Oslo (Norway) we've had these LED lights for several years, and the snow shields have never (afaik) had any problems keeping the lights visible, even during our regular snow storms.
Here's a detail from a photo of a local junction which I took for my wife. She is responsible for making public transport in the region as efficient as possible, which includes giving priority to buses and trams in all intersections:
http://tmsw.no/trafikklys.jpg
Terje
PS. Here's a link to the least useful program I have even written, pi-search, which can locate digit strings anywhere within the first 1e9 digits of pi:
http://tmsw.no/pi-search/
"almost all programming can be viewed as an exercise in caching"
O (red)
O (yellow)
. (green)
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?
We need heated road signs!
Ever wondered why stop signs are octogonal in shape?
The answer: being the most important traffic sign, they have this unique shape so that they are distinguishable from all other signs even when covered in snow.
So snow covered signs are a real concern, and yes, designers did think about the issue!
> 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
http://www.mendosa.com/snow.html
and
http://en.wikipedia.org/wiki/Eskimo_words_for_snow
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This is an opportunity, not a problem. Pack the lights with a nice long half-life radioisotope that we want to dispose of and let them melt their own snow. That way we still get all of the green benefits of LED over incandescent.
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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.
I don't think we need more rules, most of them could be relaxed, and relaxed a lot. The only evidence that I need is that, as I said, the majority of drivers relax the rules and drive as such already. I do not believe that it makes sense to set the bar for proper driving above what the average person is actually going to do on the road.
~40K dead Americans per year say you are wrong.
The real problem is NOT the people breaking the rules on purpose. They generally are paying attention, know the rules, and are ready to make adjustments. The problem is the people who either don't know the rules in the first place, or aren't paying attention. There is a HUGE difference between rolling through a stop sign at an empty intersection with unobstructed visibility, and rolling through without even looking because you were playing with your radio.
After 20 years of studying drivers and how accidents happen, I can tell you that you are wrong about them paying attention.
90+% of drivers are operating on autopilot. They are not paying attention and are just letting the autopilot handle everything. This is one reason that they take driving for granted and feel just fine texting or talking on a cell phone while running other drivers off the road. Most crashes happen when 2 inattentive drivers hit each other. If you have an inattentive drive and someone who is actually driving the driver avoids the person who is oblivious to the situation.
Who cares if I only bring my car down to second gear at stop signs? I am ready to stop. If there's another car who has right of way, I stop. If there's no other cars, I am slow enough to stop if I need to because someone else is blowing through, so no safety hazard is caused. If i have enough visibility to roll through at the speed that I am rolling through, and the situation isn't a dangerous one, then... how exactly does the rule make sense?
I care and so does anyone who avoids you hitting them because your "only dropping to 2nd gear for stop lights" becomes part of your autopilot and often you may not actually notice another car has already stopped at the intersection and is now proceeding to use their right of way when you blow the red/stop sign.
I have seen drivers (I hate to use this term for commuters who have somehow ended up behind the wheel and have no interest in teh art of driving) use this same argument and then drive and fail to notice other cars at intersections as they blow lights/signs. They still say that everything was clear and that there was no other traffic due to autopilot.
The advantage of your post is that it clarifies what the person who got killed did wrong. They went through an intersection while assuming other traffic would behave in a given way without even observing the traffic to see if this was likely. I really don't care if you have a green if it looks like an SUV coming up to a red and who will T bone you, is not slowing, don't just say "I have the right of way!" and head to your death. You will be in the right and just as dead as if you were not in the right.
If people cared about highway deaths we'd see a few things.
1. The news would report how many people died in the roads of their state the previous day and across the US.
2. Laws would begin to target bad drivers and not boogiemen like speeders and drunk drivers.
#2 sounds unbelievable so I should explain. When you are just as impaired using a cell phone as you are at the legal BAC level for DWI and only one of these has heavy legal ramifications... yeah, a boogieman has been created. Also if you research the criteria for a drunk driving crash you may be amazed at how a crash with no alcohol can still be classed as a drunk driving crash.
The police say that speed is the #1 cause of crashes. This is wrong. putting things where they do not belong is the #1 cause. If we wanted to reduce raod deaths the police would crack down on people rolling reds and stop signs, people commuting in the wrong lane, improper signal use, and other things which indicate bad drivers. Get the inattentive dummies off the road and watch the death rate plummet.
Let's ignore the positional arguments for now - yes, everyone SHOULD know that the light on top is the red one, etc. But it is obviously not the case. Some people are just not that smart.
I have always understood that the lenses which used to give lights their color, in the green case, was not really a pure green but had a tint of blue. This allowed those with green colorblindness to still distinguish the light from the others. However, it is VERY noticeable that the green LED lights are NOT the same color as the old lenses, but appear to be more of a true green. Is there a reason why they weren't made the same blue/green? Or did someone just forget?
It may be possible, if they can't produce a blended LED, to simply include some blue LEDs in the matrix as well, which should to most of us produce a blended color.
I have seen some red LED lights include a white flashing ring or center dot - this really brings attention to the light. Totally non-standard that I have seen though.
With the LED matrix lights, it is now quite simple to create shaped lights. A distinctive square or rectangular (would likely require redesigned light fixtures) design on the stop light would make it more distinguishable.
I remember the horizontal fixtures in Quebec - but I remember that the stop lights appeared on BOTH ends of the fixture - that is there were TWO lights on the outside when STOP.
What needs to happen now is standards for future replacements and new installations so that they can be ready in the future.
rm
Sci-Fi Storm
Why would energy use for melting the snow be an issue? The heating element doesn't need to be on all the time. It could be activated by a photocell (obviously there would have to be some sort of provision for night time in that), or remotely by radio control, or periodically when the temperature drops below freezing, or only during certain months. Over the life of the light (the thing wouldn't even come on at all 2/3 of the year in most places), the energy cost should be negligible. Incorporating it into the design of future lights might cost what...10, 20 bucks? That barely eats into the savings of going with LEDs at all.
Isn’t that why the simple and effective solution called a “roof” was invented for?
Just put a box around it, with a flat, transparent, 45 downwards facing surface in front of the light. There you go. Problem solved.
You can even coat it with a water-repelling substance, to prevent fogging.
Gravity will do the rest.
Oh wait... they don’t believe in gravity, in the midwest, right? ^^
Any sufficiently advanced intelligence is indistinguishable from stupidity.
all of our lights should be gas powered with mechanical shutters to change which lamp is visible. And we could have a small booth with each intersection that housed a person to operate the signals, giving them employment and shelter in winter. As for the LED lights, a bit of research would have helped, it's not as if the entire world suddenly woke up to find LEDs instead of incandescent globe, offs!
There was an unknown error in the submission.
That's why stop signs are the only road sign that's hexagonal in shape. So even if it is covered in snow, you should still be able to recognize it as a stop sign.