LED Traffic lights unable to handle winter weather. Accidents ensue.

[TheMightyFavog]

http://www.greenbaypressgazette.com/article/20091216/GPG0101/912160592/1978/LED-traffic-signals-don-t-melt-snow-blamed-for-accidents



MILWAUKEE — Cities around the country that have installed energy-efficient traffic lights are discovering a hazardous downside: The bulbs don't burn hot enough to melt snow and can become crusted over in a storm — a problem blamed for dozens of accidents and at least one death.

"I've never had to put up with this in the past," said Duane Kassens, a driver from West Bend who got into a fender-bender recently because he couldn't see the lights. "The police officer told me the new lights weren't melting the snow. How is that safe?"

Many communities, including Green Bay, are using LED bulbs in some of their traffic lights because they use 90 percent less energy than the old incandescent variety, last far longer and save money. Their great advantage is also their drawback: They do not waste energy by producing heat.

Authorities in several states are testing possible solutions, including installing weather shields, adding heating elements like those used in airport runway lights, or coating the lights with water-repellent substances.

[tridim]

1. It's stunning that this wasn't tested before implimentation.

[Robb]

2. More stunning the colder municipalities

...didn't see this coming.

[MineralMan]

3. Consider the folks who are in charge of such things. Most

can't figure out how to use toilet paper.

[Kolesar]

5. The Army did not realize the composite-body helicopters would let radio-frequency signals through...

...the skin.

So they did not bother to test the electronics modules in the helicopter for high RF fields. They crashed. The helicopter has been discontinued (I think it was the Blackhawk). The Navy version of the helicopter was ok because they ran more tests at high RF fields (as are created by the sweep radar on a ship).

[TheMightyFavog]

6. Let's not even get started on the V-22 Osprey.

How many Marines have died in those deathtraps?

[Kolesar]

9. Don't see any "Harrier" jump-jets anymore, either...eom

[TheMightyFavog]

13. They're still being used.

http://en.wikipedia.org/wiki/AV8B

The Harrier probably will disappear when the VTOL JSF is introduced.

[Kolesar]

17. Thanks ...eom

[virgogal]

4. And soon,to save the earth,we will all have lighbulbs containing mercury.

Is it me,or is some of this "green" stuff just plain nuts?

[Kolesar]

7. The mercury content is slight and not much of a risk

Many bulbs are sent to special waste facilities.
It is not as bad as the mercury released from burning coal at a power plant.

[dysfunctional press]

10. i didn't realize that led lightbulbs contain mercury.

:shrug:

[virgogal]

19. Yep! See link for cleanup of a a broken one.

http://www.energystar.gov/ia/products/lighting/cfls/downloads/CFL_Cleanup_and_Disposal.pdf

[dysfunctional press]

20. those are cfl's, not led's.

led lightbulbs will likely replace cfl's in the not-to-distant future...they're already becoming available.

[spin]

12. I hate pollution because I grew up in an industrialized area, but...

much of the effort to stop global warming is ridiculous.

Green stop lights that don't work in the winter is a good example of stupidity.

[dysfunctional press]

21. using led bulbs in traffic lights is more about saving money than climate change.

they're 90% cheaper to operate, and they last a whole lot longer.

[spin]

29. But stop lights that fail in winter are a bad investment. (n/t)

[dysfunctional press]

32. i'm pretty sure that when the investment was made- they weren't aware of the failings...

retro-fitting the led-using light fixtures with some type of weather/other -activated heating element is probably the most cost-effective solution.

since they would be used very sporadically, even in winter- their power consumption would be fairly nominal, especially in comparison to using incandescent bulbs 24 hours a day, 7 days a week, 365 days a year.

[Gold Metal Flake]

56. All flourescent light bulbs have mercury.

Have since their invention.

But this thread is discussing LED lights.

[Larkspur]

8. They were probably tested in California or the South in the summer

There was certainly a flaw in the testing plan for these LED bulbs. One year for Christmas, I used LED C9 lights as ground border lights, but they could not withstand the frozen sludge that the plow left in the front, so I had to go back to the regular C9 bulbs, which could melt the snow. I use the LED lights on the bushes and where there isn't much snow.

[Tesha]

14. Funny -- LED traffic lights have been working fine here in New Hampshire for years.

And it gets cold and even snows here.

There seem to be folks opposed to anything that
might decrease our dependence on energy.

Tesha

[Larkspur]

18. From personal use, I know that LED lights don't melt snow

I live in Northeast CT, so I know what snow is.

NH probably compensated for the lack of heat LED's give.

[apocalypsehow]

34. Funny --erecting a big, huge, honking strawman is a very poor way to discuss the issues of the day.

Now, unless you can find me an expressed opinion or quote from the OP's article that suggests that either the author of the article or the OP himself is

"opposed to anything that might decrease our dependence on energy"

you really need to retract that statement and start over.

Unless you have some evidence that the author of the article, say, just made that entire story up? Is that what you're saying? That Mr. Ramde fabricated the facts he cites in the article he penned? If the answer is yes I advise you contact the greenbaypressgazette.com's ombudsman or chief editor, and express your concerns. He or she will, of course, want to review your evidence for the claim that the reporter cited did, indeed, fabricate the story that ran on their site. The Associated Press would no doubt like to hear from you, too.

How about it? :shrug:


Edit: punctuation.

[Occulus]

40. Hi, um, yeah, LED stoplights don't melt accumulated snow

Did you miss that part?

Part of the problem is in the design of the lights themselves, specifically the presence of any metal cuff surrounding the light. That cuff (and not all stoplights have it) gives snow a great place to pile up. The heat of the previous style lamps was sufficient to melt the snow before it could build up, but the LED lamps are cooler (a LOT cooler) and can't melt the snow fast enough for it to not build up.

This isn't "folks opposed to anything that might decrease our dependence on energy" at all. Poor foresight and bad design, perhaps, but there's no ulterior motive at work here.

[Xithras]

23. Funny you should mention that. We're finding that they don't work well in California either.

A friend works for Sacramento County and mentioned that they're seeing LED light failures in as little as a year. Those black-painted stoplight housings can apparently get up to 180+ degrees inside on a hot 105 degree summer day, and neither the bulbs or the supporting electronics deal with the extreme heat all that well. The problem is apparently less severe when they replace the entire light tree with a unit that was designed for LED bulbs (most installations are retrofits of incandescent fixtures), but the manufacturers apparently simply sidestepped the issue by installing vents and (in a few models) fans to keep the internal temperatures down. As my friend asked; "What's going to happen in a couple of years when those vents start plugging with dust and bugs?"

[Edweird]

45. There aren't any elecronics in the signal heads. Only wires and lamps.

[dysfunctional press]

11. when the lights aren't working- the intersection is supposed to be treated as a 4-way stop.

there are a whole lot of ignorant drivers out there.

[spin]

15. Obviously stop lights that work are a damn good idea...

put the old ones back in for now.

Do some re-engineering. Install heaters that activate at a low temperature on LED stop lights in colder areas. Do some testing. Once the problems are eliminated, use the LED lights.

[dysfunctional press]

22. it would probably be cheaper to add heating elements than to replace all the traffic lights...

i'm assuming that it's not just a matter of changing the bulbs, but the entire fixtures.

[Xithras]

24. Which would use more power than the incandescents they replaced.

So much for the "green" argument.

[spin]

28. In that case go back to the old stop lights...

stop lights are rather important in modern society and have little effect on global warming.

[dysfunctional press]

35. led stoplights are not about global climate change.

it's about saving money for the municipalities.

[dysfunctional press]

33. but the heaters would only be used sporadically- even in winter.

so the power use wouldn't be any kind of issue, as opposed to using incandescent bulbs 24/7/365.

[Xithras]

41. Which ups the cost significantly.

Now you need electronic circuitry within each light to detect the surface temperature of the glass, electronics to control its operational state, and relays to apply power to the heating element. Suddenly, a simple "light bulb" has become a rather complex electronic device.

More importantly, the cost of the bulb and heater combination would probably far exceed the cost of an incandescent in the same situation. The primary selling point of LED traffic lights is longer lifespan, which amortizes to a lower overall operating cost. If you increase the cost of installing them, you undermine that cost savings.

[dysfunctional press]

42. it doesn't have to be all that complex.

it isn't rocket science, and there are many types of electronic sensors that are extremely inexpensive.

"The primary selling point of LED traffic lights is longer lifespan"

no- that's ONE of the selling points. the PRIMARY selling point is that they use 90% less power.

"More importantly, the cost of the bulb and heater combination would probably far exceed the cost of an incandescent in the same situation."

do you have any actual figures to support or even suggest such a claim?

for instance- how expensive are the electric wired defrosters in car windows to manufacture and operate?

[Xithras]

43. Not rocket science, but not as simple as you seem to assume.

no- that's ONE of the selling points. the PRIMARY selling point is that they use 90% less power.

Let me correct that. The PRIMARY selling point is a lower TCO. The initial purchase costs of an LED array are massive compared to that of incandescents. Industrial halogens, used in most incandescent fixtures, are purchased in bulk for as little as $5 per bulb. Converting a single intersection to all LED lights averages about $2000, and will cost $100-$200 per replacement bulb after that. Overall cost of ownership is lowered in the LED array through a combination of lowered electrical costs, extended lifespan reducing replacement rates, and the ability to reduce the human workstaff. Over the lifespan of the bulb, it's actually a combination of these that reduce the overall cost below that of an incandescent.

Environmental considerations are tertiary, if they're considered at all. The real discussion begins and ends with cost.

it isn't rocket science, and there are many types of electronic sensors that are extremely inexpensive.
That depends on how accurate you want the system to be. An extremely simple relay with thermistor to measure air temp can be put together for only a few bucks, but it's not going to be very accurate at measuring surface temps at the glass surface. If you set your margin too low, it won't pick up on surface cooking caused by wind and other factors, and will freeze over before the temp drops enough to activate the heater. Set it too high, and you'll be running the heater when it isn't needed, negating a lot of the power savings. Accurate defrosting would pretty much require that the glass temperature be measured directly, which ups cost and installation complexity by a relatively large margin. This is especially true in retrofits where the LED lights sit behind a colored lens and don't have direct contact with the glass (requiring an even more complex and expensive retrofit).

do you have any actual figures to support or even suggest such a claim?
I don't need actual figures. Common sense, an MS in CS with a minor in EE, and 20 years of electronics development and systems integration work tell me everything I need to know.

One thing you need to keep in mind is that the actual cash savings per bulb is quite low to start with. The high startup costs take a long time to counteract, and the actual savings when the bulb reaches it's EOL is quite small. The transition is only worthwhile for most municipalities because they're maintaining hundreds or thousands of these bulbs, and the cost savings as an aggregate can be substantial. That's why the word "relatively" is so important in my post above. Even a fairly small change in per-bulb TCO can have a huge impact on the economic viability of LED bulb adoption by most larger cities.

[dysfunctional press]

44. then they need to do what ever new hampshire has figured out...

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=389&topic_id=7243083&mesg_id=7243216

"Environmental considerations are tertiary, if they're considered at all. The real discussion begins and ends with cost."

i never claimed that it had anything whatsoever to do with environmental concerns

btw- with all your background, it should be pretty simple for you to answer the question(s) i posed to you about those wired defrosters in car windows...how about it? :shrug:

[apocalypsehow]

49. Ummmm, hate to point this out, but that post you linked to is pretty much spun, woven bullshit.

Using a discredited source to back up an argument of your own pretty much...discredits you.

Please try again.

[dysfunctional press]

52. "Using a discredited source.."

please-

1.point out when/where/how the source has been discredited.

2.(for the 3rd time requested) answer the question about car window defrosters. (and/or headlamp defrosters that are also available, if you prefer)

[apocalypsehow]

54. 1. Read the replies to the link you posted: it's really not all that hard even for the semi-literate

2. For the first and only time: I wasn't asked that question, and have no real interest in addressing it in any event. It's irrelevant to the discussion at hand. Go badger someone else about it. But please cease further discrediting yourself by referring to posts that have themselves been shown to be barrels of typed, steaming bullshit. Thanks.

[apocalypsehow]

55. On second thought, I'd better help you out: posters who tend to chronic dishonesty seem to need help

Start here:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x7243083#7243308

Money quote: "From personal use, I know that LED lights don't melt snow"

Then use that scrolly-thingy on your mouse and go down to this (full disclosure, that's a post by me, myself & I):

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x7243083#7244349

When the fifteen-twenty minutes that it'll probably take you to get through that post are done, it's back to the scrolly-thingy on your mouse again for this next reply:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x7243083#7245520

Money quote: "Part of the problem is in the design of the lights themselves, specifically the presence of any metal cuff surrounding the light. That cuff (and not all stoplights have it) gives snow a great place to pile up. The heat of the previous style lamps was sufficient to melt the snow before it could build up, but the LED lamps are cooler (a LOT cooler) and can't melt the snow fast enough for it to not build up"

Have fun bringing yourself up to speed! :thumbsup:

[Edweird]

46. No, you can replace the individual lamps. They are interchangeable.

[dysfunctional press]

53. actually- it depends on the fixtures.

the newer ones are being made specifically for led's, and don't use the same type of led bulb, from what i understand.
the older ones- they usually do just swap out bulbs.

[Edweird]

57. Do you work in the signal industry?

It's been years since I've hung a signal head, so it's possible that things have changed. But, for the record, I'm an IMSA certified signal tech. I started off digging ditches and when I left I was a project manager handling $5,000,000 in signalization and roadway lighting projects for municipalities and the Florida DOT. So I do have more than just a passing familiarity with them. But, my most recent IMSA card is dated 10 years ago.

The signals we used had reflectors/edison bases on hinges that could be removed. The LED's replaced the glass lens.

[brendan120678]

16. I've seen some snowstorms where the wind caused...

near white-out conditions, and even traveling at very slow speeds, it's tough to tell you're approaching or in an intersection. All you really can see are the tail lights ahead of you, and the R-Y-G of the traffic lights. Unless, of course, the traffic lights are covered with ice and snow.

[yodoobo]

25. adding heating elements

At that point they should just go back to regular bulbs.

regular bulbs are inefficient because they produce heat and light.

Going to a bulb that is efficient because it doesn't produce heat and then adding a heater is just dumb.

[tridim]

27. Not dumb if the heaters are only used a few days a year.

[yodoobo]

36. Maybe. But its not just the temp

Now you have another subsystem to manufacture, transport and then maintain. That has an environmental impact as well.

In areas where it doesn't get cold enough often, many will fail in between uses and then not be noticed until its a cold day. To resolve that you need to test them occasionally. You could have a remote system for testing them, but now the complexity rises and costs increase. Testing them individually wouldn't be practical.

Net net its probably a minor savings in moderate environments, but the reliability cost is still present. And in safety systems, reduced reliability has a human cost. In cold environments, this is a loss.

[tridim]

37. I think part of the problem is the LED bulbs are retrofitted..

to the old style signals.

How about putting a single halogen bulb in with the LED array and arming it remotely or via a temperature sensor? I'm pretty sure that most signals are already networked.

Short of that it might be time to invest in some infrastructure and completely redesign the whole system.

[Edweird]

47. The controllers are (usually) networked. They are those big aluminum boxes

you see near intersections. The actual signal head is not. Due to the complexities of the safety mechanisms, a dual/switchable illumination scheme would be insanely expensive.

[Edweird]

51. When you consider everything else that will be required to install and maintain

'heaters', it would make much more sense to just go back to the inandescents.

[HiFructosePronSyrup]

26. The fault lies with the drivers.

People who cruise through intersections when the lights aren't working (blackouts, for instance) are worse then drunk drivers, in stupidity if not in frequency, IMO.

[ieoeja]

30. Noone said the lights aren't working.

They are just covered by snow. And may only be those facing the blowing snow. So people from one direction are treating it like a 4-way stop, while everybody is cruising through the intersection normally with no idea that the lights are blocked for people in that one direction.

[HiFructosePronSyrup]

31. Then you treat it like any stop sign.

And wait until it's clear to proceed. That's just basic defensive driving.

[ieoeja]

38. What if it is never clear?

I don't know about your neck of the woods, but around here there are lights during rush hour that never see it clear.

So you have cross traffic moving through the light non-stop until their light turns red. You can not see if your light is now green, but can surmise from the cross-traffic stopping that it is. So you go.

Or you follow your rules, in which case you sit at the light for an hour-and-a-half until there is finally no cross traffic.

[HiFructosePronSyrup]

39. Following your rules you pull out into traffic and cause a crash.

Following my rules then if the cross traffic does have a working red light, they all come to a stop, at which point they'd be yeilding to you AND they can wave you through if you're unsure, at which point you procede cautious, making sure all lanes are yielding.

[McCainIncNews]

48. There is a solution

There is an easy and cost effective solution to this problem that is fast and uncomplicated; therefore helping cities quickly respond to the problem and alleviate more potential hazards this winter season. The solution is a scoop visor, available through McCain Inc. (www.mccain-inc.com/traffic/item/signals/signal-visors.html). The scoop visor is specifically designed to help reduce snow deposits and build up on the face of LED traffic signals. It’s a simple and straightforward fix that allows cities to continue pursuing their eco-friendly goals of installing energy efficient LED’s, without jeopardizing the safety of their citizens.

[Edweird]

50. Uh, nobody here is in the biz.

I'm an IMSA certified tech, but I work as a utility lineman. Good luck.

[Gold Metal Flake]

58. Wow. Not often you see outright spam here.