The LED Traffic Light and the Danger of

Well you seemed to like the jacket, so… I’ll keep it I have a bit of a fascination with stop lights (or traffic lights, if you prefer)

They boil down to remarkably simple devices, little more than indicators, but thanks to driver’s education and the magic of the human brain, they are remarkably effective at safely controlling traffic at intersections Well, most of the time Now, there’s so much to get into regarding traffic lights Traffic engineering is a fascinating subject which I don’t feel qualified to discuss, but there’s quite the rabbit hole to fall into This video is about a simple but groundbreaking innovation in the traffic light and the lessons it can tell us about innovation in general

This is about the LED traffic light, and the caution of “but sometimes” I live in an area of my town that’s not terribly well traveled Though there are many 4 lane roads with speed limits of 35 to 40 miles an hour, the traffic volume honestly doesn’t often justify having two lanes in each direction Many of the stop lights in this area have been neglected, and are still using good-’ol fashioned incandescent bulbs with colored glass lenses Actually, some are so old that they still have the written text “WALK’ and “DON’T WALK” in their pedestrian signals, and there are even a few that use the old 8 inch lenses for the green and yellow lights, with only the important red light getting a full 12 inch lens

Granted, these stop lights have had their control systems upgraded over the years There are vehicle presence detectors embedded in the road surface to alter their timing and behavior, and they are equipped with photocells to detect the tuned strobe light on emergency vehicles and stop traffic in opposing directions And some have even had countdown timers added to the pedestrian signals But the fixtures themselves have remained mostly unchanged They are still the same incandescent traffic lights that may very well have been in place for a good number of decades

I should add that vehicle presence detection has been around long before the LED traffic light, and it’s very likely these intersections have the same control equipment they’ve always had But in any case, the fact that they are still using incandescent lamp technology is a little odd

Setting aside the nostalgic or aesthetic reasons to prefer an incandescent stop light (I’ll admit the fade-in fade-out as each light changes states is charming), the LED traffic light is just objectively better in nearly every respect For example, Incandescent stoplight fixtures, because they are designed to be opened to replace the bulb, typically get dirty on the inside over time And it seems the technicians who replace the lamps often don’t seem bothered to clean the lenses or reflectors This leads to many lights with a dull appearance that’s hard to see in bright sunlight This obviously isn’t great, and is actually kinda dangerous, but whatever

The LED light, on the other hand, is completely sealed In fact here’s an LED traffic light module

Yes, they really are this big, they just seem much smaller when they’re grandstanding on their pedestals or hanging up high in the air These are designed with the ability to replace the lenses in existing incandescent lights and function as a retrofit device, as well as simply be the default standard for new traffic light installations Because the entire module is replaced if needed, it can be completely sealed LED lights thus don’t end up looking like that These LED modules use about a 10th the energy of the incandescent lights they replace, which is not only great for energy savings, but it means battery backups for the lighting control system can keep the intersection controlled for hours even during a blackout And of course, they last so much longer than the light bulbs in an old fashioned fixture do This 116 watt light from Sylvania only lasts 8,000 hours, which may seem like a lot, but assuming a roughly 50/50 on time for green and red, that won’t even cover two years

And since pretty much every intersection has at least 2 lights visible in each direction, there’s a total of at least 16 of these bad boys in a very small intersection, not including yellow This would mean that a light will go out about every two months, and let me tell you, that’s remarkably in line with how often I see a light go out at any given intersection In fact, on the day I left to start taking photos of the stoplights around me like the big ‘ol dork that I am, this light burnt out Granted, there are two other lights providing redundancy, but they're also really dirty and hard to see anyway I went out again a few days later to take some photos I had forgotten to take, and now this light is also out

What fun! At this one intersection, including all arrows, pedestrian signals, and standard orb indicators, there are 94 lights just waiting to burn out Conversely, you almost never see an LED stoplight with a signal that’s out They last so long that it’s a very rare occurrence It does happen, it’s not like they last forever But even when they do fail, some designs don’t even fail all at once, with this module still mostly functional save for some dead diodes

In the past two years, I’ve only seen one LED light completely fail anywhere, whereas I’ve seen about a dozen lights go out just in my neighborhood Now, I can’t tell you why my local streets and sanitation department (or whatever agency is tasked with maintaining these specific traffic controls) hasn’t invested in retrofitting these stoplights with LED replacements They’re just an odd holdout, I guess, or perhaps they think it’s cheaper to just do things as they are News flash– it isn’t, because if these lights do use 116 watt bulbs, then with pedestrian signals included, at any given time the intersection is using around a kilowatt and a half (or more), meaning it costs about $360 to operate daily assuming average rates in Illinois

Add to that the cost of relamping the fixtures every two years , or far more likely the reactionary maintenance when a lamp fails multiple times a year, and it seems really foolish to still be using these traffic lights as they are Especially because these modules typically end up on eBay or elsewhere for about $10 each I don’t know how much they cost new from the manufacturer, but I can’t imagine they’re terribly expensive But, when the LED stoplight first made its way onto the scene, one of its central advantages became a disadvantage See, because the good ‘ol incandescent bulb is so terribly inefficient, it spews a lot of heat out all sides and kept the fixtures toasty warm

This had the lovely side effect of keeping snow and ice from building up on them in cold climates Many municipalities started discovering that their new LED fixtures, which are 10 times more efficient and thus release just 10% the heat, didn’t do that In bad snow storms with high winds, it is very possible for the snow to make its way past the visor and stick to the face of the stoplight Not producing enough heat to melt this snow, the LED stop light might become impossible to see in this scenario This caused quite a few accidents, some of which were regrettably fatal

However, if the drivers at fault remembered their driver’s education, a stoplight that isn’t indicating should be treated as a stop sign, turning the intersection into an all-way stop But people are stupid, so accidents happen As you may imagine, the news reports started flooding in “Energy efficient stop lights cause accidents!” “These new LED stoplights can’t melt snow!” “The green revolution know no bounds–cold traffic lights leave drivers confused!” Et cetera, et cetera, et cetera The really stupid articles pointed out that, while a solution might be possible, it would eat into the energy savings presented by the LEDs

That is a really dumb argument, as we’ll discuss momentarily I even recall a news report when I was younger suggesting that a heated surface would use MORE energy than an incandescent traffic light, so really, what’s the point?! This is the danger of “But sometimes” It goes a little something like this: The LED stoplight is more energy efficient, costs less to operate, requires less maintenance, can allow for a feasible battery backup solution, lasts longer, are brighter and easier to see (particularly in direct sunlight) BUT SOMETIMES snow and ice builds up on them, so clearly they are bad Ugh, this makes me so disappointed in humanity! When there’s a new innovation which changes how we do things for the better, its benefits are obvious The LED stoplight is a perfect example

It allows stoplights to better accomplish their rather important task of being visible, makes them more reliable than (and with battery backup makes them functionally superior to) an incandescent light, and saves municipalities thousands of dollars, with Wisconsin reporting in 2009 that they save $750,000 in energy costs annually, which isn’t even mentioning maintenance costs However, when the “But Sometimes” rears its ugly head, people tend to freak out Suddenly, all those benefits go away, because in this one particular facet of stoplight functionality, the wasteful and maintenance-heavy incandescent lamp is accidentally superior Suddenly, when the new solution presents a new problem, all we think about is the problem Which leads to the truly stupid part of this argument

But Sometimes occurs only some of the time! It’s a sometimes! Articles that complain about a potential solution requiring more energy, and thus reducing the efficiency of the new LED stop light, just kinda gloss over the fact that on every day it’s NOT snowing, the issue is completely irrelevant Sure, if we add heaters to the LED module to melt snow it might need more power, but only when it’s snowing, dingus! It wouldn’t take too much imagination to enable wireless control of an intersection’s stoplights to turn on the heaters while it snows Even if the lights used a bit more power while the heaters are on, the other 300 days of the year when it’s NOT snowing don’t just go away It doesn’t take too much thinking to realize that it's still saving a lot of energy over the long run And again, the traffic light is not at fault when an accident occurs

All drivers know (or at least should know) that a malfunctioning traffic light means you must stop and proceed with caution But we trust people so little on remembering this simple procedure that nearly every intersection has a folded up stop sign ready to be deployed when the traffic lights fail I’m not opposed to that, I think it’s a good idea, but in reality it shouldn’t be necessary Also, in personal experience, a snow storm severe enough to cause buildup on the traffic light lenses is pretty out of the ordinary I’ve never personally encountered a traffic light that’s completely obscured with snow

I’ve seen some partially, but never enough to make the signal impossible to distinguish After all, there are pretty big visors over the lenses, so it’s got to be a real blizzard to cause a problem And really, in those conditions, you should just avoid driving altogether This isn’t to say that the problem doesn’t happen Surely it does

But come on, it’s not frequent at all Now, the correct response to the “but sometimes” is to account for that sometimes and solve the problem One potential way that doesn’t use any energy is through an altered visor with a scoop on top designed to redirect wind to flow across the lens and blow snow off of it But for those wanting a more high-tech solution, well take a look at this General Electric now sells what they call “GTX Flex LED Heated Shell”

These traffic light modules have defroster wires across their face, just like the rear window of your car What’s more, they have sensors onboard measuring temperature and humidity to determine when icing conditions are likely and automatically switch on the heaters The spec sheet says these heaters use only 30 watts, which means even when they are all on, a three-light traffic light is using less power than a single incandescent bulb Not much less, but I must remind you that the need for the heater is rare, and only a sometimes It looks like this is a relatively new product, with the site touting it as NEW and the copyright date on the spec sheet being 2016

So it seems we got along well enough without this innovation for, uh, for a while Probably because people realized how infrequent the problem actually is, but anyway–the problem has been solved The “but sometimes” is now a never The moral of this story is that when faced with a unique, unforeseen, or difficult problem that comes about as a result of doing things in a different way, don’t just give up! It’s beyond foolish to fly in the face of progress, especially when the result of the progress is so obviously better, just because there’s a tiny little sometimes maybe issue that we haven’t had before I’ll bet you no municipality that has switched to LED traffic signals wants to go back to the old way of doing things

But that’s what news articles and media coverage like this seem to advocate for Now, obviously I don’t want us to not acknowledge problems That would be silly But when discussing these problems, we need to look at them from all sides Just how bad is the problem, really? How often does it occur? What would we be giving up if we abandoned our efforts, and should we abandon them? What can we do to combat the problem? Does the problem need a technical fix, or do we need to re-educate people and adjust their behavior? Perhaps the problem isn’t so much a problem, rather it’s a need for change elsewhere

But for goodness sake, we need to work to solve the problem Every innovation has changed how we do things in some way That’s the very idea of progress Sometimes this change brings new issues to light, and may bring inconveniences from time to time But I don’t think this should be seen as a reason to stop progress

I hope that as new technologies and innovations become available that provide us advantages just as the LED traffic light has that we don’t simply focus on the new problems they might create Together, we should be asking how to solve those new problems When we ask that question and work towards the answers, we can truly make progress Ok, so there’s some other stuff I want to bring up real quick First, I’m officially launching my second channel

Head on over to Tecnhnology Connections 2 if you’d like to see what’s on the inside of one of these LED modules I’ve always been a little curious Don’t, uh, don’t go over just yet, hang on a sec Ok, well here’s a card, but the endscreen will have it, too And there’s a link down below

One thing that I’ve noticed change about traffic light behavior is the timing of the right turn arrow I realize this whole video has been from the perspective of the US, where we drive on the right and our traffic signals look like, well like that and all the things you’ve been seeing in the video, so maybe this isn’t a thing in other countries, and honestly this could be a regional thing within the US But at intersections where there are both left turn only and right turn only lanes, the right turn lane will typically get a green arrow while the opposing traffic gets a protected left, because no one will be coming from the left hand side going straight across It used to be very common for the green arrow to light up as soon as the the yellow light appeared, which was great because it meant if you were turning right, you knew that you could just proceed even though forward traffic was about to stop Most intersections these days seem to wait until the opposing traffic gets their protected left before illuminating the right turn arrow, which means you need to stop before you actually get that arrow

I suppose this might be a safety thing, but really I can’t see how much safer it is because pedestrians would not be entering the intersection at all while there’s a protected left because vehicles will be crossing their path no matter which direction they are going And it’s really annoying in this age of distracted driving, because some drivers see the light turning red, come to a stop, and then look at their phones without realizing there's a turn arrow now illuminated If the arrow were already lit, they could have just kept going and annoyed someone elsewhere Going back to my particular town’s situation, there’s one intersection near me that’s an absolute hodge podge of stuff Almost nothing matches anymore in this intersection There are individual LED retrofits among incandescent lights, such as this pair of signals where there is only one LED signal among the 10 total lights

But most amusingly, the pedestrian signals are almost all completely different There are still some old written Walk/Don’t Walk signs combines into a single fixture, then there’s the newer pictographic signals with the talk to the hand and the walking white guy, then there’s an LED version of the same thing with two distinct shapes, and there’s an LED signal where the shapes are combined, and finally there’s ONE that has a countdown timer That strikes me as particularly odd because it means the controller for this intersection is capable of driving a countdown timer, so clearly it has been updated within the last decade or two, but there are some comparatively ancient fixtures here I realize this style of light where there are multiple diodes right at the face that fail over time is kind of an old style at this point Most newer traffic lights are like these, where they are designed to mimic how incandescent fixtures look

In fact, GE calls these “incandescent look” That’s part of why I want to check out the innards of one of these I doubt there’s a single 10W LED chip in here, so I would imagine they also don’t necessarily fail all together, but it would be a lot harder to tell if it’s failing at a glance I glossed over the vehicle presence detection a little bit and just showed what it looks like, and sometimes this isn’t even visible Generally, there will be a loop of wire embedded below the road surface that's designed

(camera beeped) Really? I glossed over the vehicle presence detection a little bit and just showed what it looks like, and sometimes this isn’t even visible Generally, there will be loops of wire embedded below the road surface that are designed to detect a change in their magnetic field brought about by a large metal object above them (such as a vehicle) You can often see these, particularly if they were added to an already existing road surface Sometimes you’ll notice them way far back from the intersection, and by adding them here the traffic control system can count how many vehicles are approaching and thus how much time is needed for them to cross the intersection

There’s some pretty clever thought going into all these systems Oh, and sometimes you’ll see cameras up where the traffic signals are, and some of these are used for presence detection using computer vision Also, the emergency vehicle detectors are a pretty neat thing that perhaps you know how they work, but I’ll tell ya anyway I said “tuned strobe light” earlier What I mean by that is that emergency vehicles have a single white strobe light, often in the center of their light bars, which flashes at a very specific frequency

It’s often hard to see on video because strobe lights and video just don’t really get along, but it’s this one here on this ambulance The traffic light controller is looking for a signal at that specific frequency coming from the photocells up top, and when it sees it it will begin stopping traffic

These white indicators are used to confirm to the driver of the emergency vehicle that the signal was received and that opposing traffic is being stopped In Illinois, where I live, the lights will flash in the direction the emergency vehicle is coming from, and they will illuminate steadily for opposing traffic to warn them an emergency vehicle is coming Interestingly, this isn’t really taught in driver’s ed, and the lights don’t have any sort of sign to explain their purpose, but hopefully enough people have figured this out to make them useful Lastly, for those towns who like the charm of these old 8 inch stop light fixtures, you’ll be happy to know that GE (and probably others, too) make LED retrofits for these So come on, guys

Let’s get with the program Thanks for watching, I hope you enjoyed the video! If this is your first time coming across the channel, please consider subscribing As always, a HUGE thank you to supporters on Patreon! Your support is what keeps these videos coming If you’re interested in supporting the channel too, please check out my Patreon page! Thanks for your consideration Alright, so if you would, head on over to Technology Connections 2, and it’d be super great if you’d subscribe there! I’ll be putting more extra content up there as time goes on

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