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.

Comments

Too bad we don't have rules to deal with this

[Anonymous Coward]

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.

Re:Too bad we don't have rules to deal with this

[nschubach]

I thought of this, but in the snow cover situation, only one side thinks it's a four way stop. You'd have to have a "snow sensor" and shut down all 4 sides of the light for that to work.

Re:Too bad we don't have rules to deal with this

[Hognoxious]

If you get to an intersection and the light isn't working or isn't visible, you treat it like a four-way stop.

He did - he went straight through just like anyone driving a Dodge RAM does.

Re:Too bad we don't have rules to deal with this

[chaim79]

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:Too bad we don't have rules to deal with this

[Moryath]

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.

Re:Too bad we don't have rules to deal with this

[necro81]

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.

Re:Too bad we don't have rules to deal with this

[JetTredmont]

Of course. You will obviously save more energy by using a heat-generating bulb 24/7/365 than adding a heat source which kicks on when needed (either by direct control or by a sensor).

This is why I took out all my light switches and just leave my lights and appliances running all the time. It saves me time and energy! Plus, with all those lights on, I run my heater less in the winter! Doubleplusgood savings!

Good Advice

[Frigga's Ring]

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.

Re:Solvable.

[YrWrstNtmr]

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:No issues in Canada

[Anonymous Coward]

"I've never seen one obstructed by snow."

Yea, because you couldn't see it.

Propaganda?

[CrazyDuke]

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!

Re:Hmm...

[CoreDump]

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.

Re:whatever happened to being careful?

[BobMcD]

This kind of comment is harmful on many levels...

1) Being 'stupid' is subjective.

2) Classifying large groups of people as 'stupid' is divisive and elitist

3) Labeling this behavior as 'stupid' implies both an acceptance of the inability to change it AND an implicit protection from the consequences of their behaviors

If you really do think a portion of the 'US of A' is 'stupid', please do us all a favor and stop saying so. You're only perpetuating the problem when the truth is the vast majority of adults are 'smart' enough to operate an intersection correctly.

If ND doesn't have this problem...

[The Rizz]

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...

Re:See what the expert says...

[Le Marteau]

> 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