How Traffic Lights Work!!

[@jdanon203]

Wow this guy is like a god. He can go into any of those silver cabinets and make the traffic lights do whatever he wants. Green lights for everyone!!

[@jovetj]

I've seen that film. It didn't end well.

[@ecaparts]

Vehicle detection sensors have NOTHING to do with what you think it is. The light is setup to always give priority ‘green’ lights to the main road. While the secondary road will NEVER get a green light until there is a vehicle detected via the sensor. He is talking about this vehicle detection sensor. He is NOT talking about those illegal devices sold on eBay, that may or may not work, which is used for emergency vehicles to trigger a green light immediately. BTW if you are stupid enough to use such a device, you WILL get caught and the fines are INSANE. Why would that be cool? In reality, what makes YOU more important than any other citizen? Doesn’t everybody else consider their time just as important?? Be careful out there and be considerate of others…

[@WilliamLutz-dj9zo]

Italian job and Gremlins.​@@jovetj

[@WilliamLutz-dj9zo]

Italian job and Gremlins.

[@WilliamLutz-dj9zo]

​@@jovetjItalian job and Gremlins.

[@juniperwinters3277]

As someone who likes to learn how things work, I love your videos. Thank You!

[@Vejitatheouji]

08:56 I feel like there a LOT of people out there that need to watch this part. I've seen so many drivers to pull up way too far and I'm sure they wonder why they never get the light!

[@WavzonRox39]

Yes! Been hoping for this explanation, Thanks!

[@MainebobOConnor]

Excellent! Traffic signals 🚦 have come a long way since the old "electric clock" timers with one fixed time and no sensors. I imagine there are software engineers who work to optimize traffic so that the fewest number of cars are stopped and idle. Or maybe AI will come along to further optimize traffic. 🚦Big Thanks. 🚦

[@ljthefro]

That optimization process is often done by civil engineers who specialize in traffic operations. But they often use different specialized software programs to perform that optimization.

[@stephenfry-gdot]

@@ljthefro Yes indeed! It typically starts in Synchro or Vistro (not an ad), but then the field engineer has to re-adjust in the field, especially when working with a corridor or grid system. Synchro and the theories that underpin it (mostly Webster Delay and the TRB Highway Capacity Manual) make a lot of default assumptions that are rarely 100% applicable to YOUR location. Zong Tian from UNR has developed another solution called WaySync that is gaining traction, so we'll see if that reaches the same level of use as Synchro. Of course there are also proprietary systems that can do "Adaptive Signal Control," but that stuff is never covered in engineering school.

[@ljthefro]

@stephenfry-gdot I wasn't gonna get bogged down replying with specifics in the comments, but thanks for providing that extra context. Fun fact: I took traffic engineering classes from Dr Tian at UNR several years ago, before life took me in a different direction professionally. Didn't know about his software...that's cool!

[@toddk968]

I think I've learned much of this from your previous videos over the months I've been watching, but nice to have a nice roundup of the system as a whole. Thanks for teaching us!

[@garylbowler]

My friend! This is totally fascinating! And yes, a break from the usual issues we are bombarded with! Kudos to you for mastering the product knowledge to be so informative! Thank you!

[@EmergencyServicesWestVictoria]

Love watching these at Midnight. There so good to just relax to before going to sleep. More explation on traffic lights. I wonder how mine work in Australia

[@kevinmayfield8638]

Like this video, thanks. Also, can you sometime, do a video on loop detectors? I have always wanted to see some details on how they are constructed and how they work.

[@matthew_tv]

Thank you for explaining this. I currently serve as a lead software engineer for Yunex Traffic, and going through your videos really helps give life to some of the awesome technology we are cooking up 👍

[@NipkowDisk]

I just love the fact that you have external STOP TIME switches in your controller cabinets; that should be mandatory in my opinion. Great video, please keep up the excellent work!

[@wizardgmb]

Thank you for the tour & especially the explanation of the phases that I wasn't sure I had properly figured out. I recognized a radar/video detection head for the first time this week. It's on a 6x4 lane intersection with a brand new firehouse 500 feet away; when the equipment heads out on an emergency call, all lights go red. Are firehouse calls treated as a separate phase?

[@railfanpat1719]

I am wondering if you have a chance to talk about how traffic lights work with railroad crossings

[@tux_the_astronaut]

Ye that would be a cool vid. Ive seen other channels talk about how crossings work and detect trains but haven’t seen much on how crossings and stoplights interact

[@DavePKW]

Thanks, that was very interesting. I work in electronics and always wondered what they used in those cabinets these days.

[@zeusbottom]

Thanks so much for putting that together! Learned a lot more!

[@shanevickers1654]

Cheers for the insight..

[@JohnRay1969]

I love his manner of speech. I would listen to him reading the dictionary and not lose interest

[@Trafficlightdoctor]

Giving me video ideals! 👀🤣

[@samanthag13]

I never knew I needed a traffic light so bad. 🤔😂

[@sams6098]

Wow.. that was truly absolutely fascinating. I was always curious about phases. Thanks for the lesson and getting up for what looks like super early in the morning to make this for us. Cheers

[@joshyaks]

9:26 - So if you're not metal enough, no green for you! Fair. 🤘😎🤘

[@xcharlie25x]

awesome, it's very simple once you get to know all the essential components

[@jjjohnson2005]

Been a fan of your vids, and love that you did this explanation video! I'd love to see more how you program in the flashing yellow arrows since they are becoming more prevalent everywhere

[@michaelkrizek6467]

Thank you very much. Now I have a video to show my girlfriend so I can explain my traffic light collection to her.

[@lukephillips5618]

Mobile, AL is gonna be retiming 174 traffic signals over the next few months. Thanks to your videos I know a bit about how that process works

[@cdarting91]

We have a lot of traffic lights that appear to use both magnetic loops and detector cameras.

[@kaneko523]

Lights are fun i learned something new today

[@LupineTendencies]

This ROCKS dude, thank you lmao. A true breath of fresh air. If you haven’t, how about a deep dive on the signals that have what I assume to be magnets beneath the lanes?

[@WilliamLutz-dj9zo]

Inductive loops under the lane surface. They act like a metal detector.

[@streetsmartstraffic]

Once again Traffic Light Doctor--Great Video!

[@whistlingtomb3299]

You have an awesome channel! I have always wondered how these work. you have earned yourself a Subscriber!

[@briank10101]

Wish everyone would proceed to move on green at the same time. Once moving, they can then increase spacing in proportion to speed.

[@zacke1434]

What would you recommend to someone that wants to get into this field?

[@earlt911]

How well do those traffic control boxes handle the weather, hot, cold, etc.? Do any of the traffic boxes have a battery backup unit (APC type) inside the cabinets? Pro's Con's .. Thanks!

[@SharkDude1]

Talk about the myth that flashing your headlights will make the traffic light turn green for you.

[@Trafficlightdoctor]

@@SharkDude1 I have a few times but haven’t made a longer in depth video of it yet! so soon!

[@KDill29]

I find this all wicked fascinating. Could you maybe cover in a video how the lights know when an emergency vehicle is coming well before the zones, and turns the lanes that the vehicle is travelling green. Along with the white strobe light on top of the light poles that blink, what that means? I assume its to get drivers attention that an emergency vehicle is coming. But an official explanation would be cool too 😂😂😂. Cool videos my dude!

[@calsadowski3230]

There are detectors in the intersection called an opticom system. They detect the flashing lights of the emergency vehicle, signal to the controller and then the controller changes the lights to green/keeps it green. The white strobe light is called a confirmation light and flashes to tell the driver of the emergency vehicle that the detector picked them up and the light is going to change.

[@daviddavidson3639]

I appreciate that they include a standard 120V plugin for troubleshooting on the box. Now if only they could think far enough ahead for the boxes to no break.

[@YaaBoyMel]

I ride motorcycles and I will say inductive loops are the worst but shout out to the drivers who understand when I wave them to come closer to me so we can get the green

[@rickhammer1905]

Very interesting!!

[@pacoj91]

Hey so yall don’t use induction loops for any traffic signals

[@alexgonick]

I didn’t know you could just walk in to the intersection and have it change. Insane.

[@bobsjers]

There are fully solar operated traffic lights in NJ.

[@bluetheta]

I wish more city DOT managers see this video. The cameras is way better than the loop and plus longer life of the intersection roadway (no need to cut for wires that turns into potholes). I know understand the random boxes on streets that don't have traffic lights - those run the street lights (lunar lights)

[@SantaFe19484]

Nice video! Do inductive sensors have a hard time picking up Corvettes, which are made mainly of fiberglass?

[@djdavionatl]

I always wonder how are the wires ran down the mast arm to the cabinets

[@robertmailhos8159]

Gdot is putting a cross Walk signal at the intersection on us 441 at Walmart drive here in Putnam county Georgia

[@jnelsoninjax]

You said that the cameras should detect bicycles, but here in my city, there is an intersection I go through that has a camera on it, and it does not detect me when I am on a bike. I have tried to find out who is in charge of the signals, but city hall tells me DOT, but I don't think DOT handles the cities traffic lights.

[@polypolyman]

This will depend on where you are, so I’d believe the advice from your city hall. In my (small) city, there are several traffic lights, but only one is actually maintained/owned by the city - the rest of the lights are on US Highways that run through town, and are therefore under CDOT (Colorado Dept. of Transportation) ownership. Any changes/etc have to go through the state.

[@mikeshr2]

I there any kind of communication between boxes to give advanced green to a slug of cars that's coming from the red upstream?

[@erice3525]

Do you ever use the FE3 bell shaped cameras down in Florida? I see them everywhere up northeast, usually the only camera controlling the intersection maybe with a radar as well

[@keithbeck8170]

How do you get a flashing red/green at the same time? I never saw one of those until I hit Jackson, MS. It only took me 45 years to see one do that.

[@matthewhintz4816]

How does that stuff not freeze in winter?

[@RASpitzer23]

The Gulf Coast doesn't really get that cold in the winter. It FEELS cold due to all the humidity, but hard freezes are a once-every-few-years thing.

[@matthewhintz4816]

@@RASpitzer23 I am talking more of up north.

[@polypolyman]

Where it gets cold, sometimes these boxes will have a layer of insulation on the outside, which helps the heat from the equipment keep the box surprisingly warm. The equipment in there is all likely to have a more industrial temperature rating (I.e. down to -20F at least) than typical office equipment. The enclosures are also sealed up to deal with driven rain, ice, etc while keeping the equipment dry. In really extreme cases, there are enclosure heaters and AC units that can be easily retrofitted on there - I’ve had more trouble with the heat in those boxes than the cold, even way down in negative double digits (not traffic signals personally, but similar industrial control equipment)

[@YehudaKatz1]

How does the controller tell the pedestrian signal how long it will have to count down? Is it just hard-coded with a certain amount of time?

[@popblender]

Great video!

[@WilliamLutz-dj9zo]

I used to hate red lights. Now they don't bother me. They give me some time to analyze the intersection. Bring on the red lights!!

[@HelpMyDogWontStop127]

3:30 why do yall put in two lights for one lane?

[@MikeDawg0007]

Curious if you have any insights, whatsoever (different places, I get it), on networked traffic lights? I can't find the article right now, but it isn't too many cities that have it implemented (heck, it may only be one). But, I think I heard about Los Angeles having networked traffic lights, so each intersection, knows what other intersections are doing, at any given time.

[@MiniModBlue]

Like and subscribe button huh?..😅 very informative as per usual

[@Trafficlightdoctor]

I try not to ask for a lot! 😂 glad you enjoyed it!

[@MiniModBlue]

@@Trafficlightdoctor it's all good, I can't like and subscribe any harder! 😭

[@jovetj]

1:35 If you want to be even more introductory, you probably should explain what "in the field" means. It's not intuitive to most people.

[@bpmunroe]

This video was helpful at explaining a lot of things, but I am still confused on zones. When you said the straight ahead zone was zone 4, I thought “oh, and the turn lane is zone 8”. But it wasn’t, it was 7. Can you walk us thru ALL the zones explaining how the numbering works?

[@marcdich]

Well, you answered the question. I was wondering if you walked out there or would it actually trigger a green light and it did so but with that being said back to the you don’t love them well I will say this you do love them. I’m only kidding, but they look so lonely sitting out there at Christmas time. Do you give me some love? Do y’all go put like Christmas ornaments on the lights and make them feel all warm and stuff if it gets too cold in the old days, they had incandescent bulbs that would keep them warm but now the LEDs don’t keep them warm, but I heard they make heaterswhich in your case you probably don’t get up getting snow down there, but if you were the heaters would keep the lenses warm to melt the snow but I have yet to see that implemented anywhere anyway real quick question whereabouts in Mississippi are you? I’m curious because my mom who passed away a couple of years ago is buried in Tylertown right off of I 55 if you know where that’s at it’s just south of Jackson.

[@jovetj]

Why does the Ped button snicker like a gopher in _Caddyshack_ ?

[@berylwhite2983]

I kind of have disagree with you you are the brains that keep it working those the machines keep it working. Yeah you weren't there the machine would stop. You do a great job

[@calvincato1561]

I want the new traffic light

[@Kaikaiblogs]

I get my traffic light😮

[@7thgrader07]

I have sat at a crosswalk for almsot an hour after pressing the button to cross at one intersection.

[@TruckzNTrainz]

We need more round a bouts. Stop lights we spend time idling...which is wasteful

[@ItsTheCostanza]

Bring back old lights that had no sensos lol

[@cubbe8]

Why not put it on ped recall

[@kens.3729]

MODOT had a Traffic Signal Box Hit by Lightning last Fall 2023 in a STL Suburb. MODOT Claim it’s been Waiting for a Replacement Part for 9-10 months. Signal has been on Basic Function for Months which gives Green to a Strip Mall Exit 🤪 and NOT to the Main Road. Makes NO Sense. 🤪👎

[@BalooUriza]

Please stop giving walk signs with a conflicting flashing yellow arrow, this kills pedestrians. If anything, a steady red left arrow during walk, and wait a second or two after the don't walk sign starts flashing before changing to a flashing red arrow. Don't just give drivers the opportunity to send it from the far side of the intersection into a long crosswalk, they won't look.

[@ljthefro]

The flashing yellow arrow is no different than the green ball here, in that it's a permissive left turn where the driver has to yield to all traffic legally in the intersection (including pedestrians crossing on the walk indication). Although some jurisdictions will show a red arrow during the walk indication and not go to FYA until the flashing hand (or even suppress the permissive left entirely when there is a conflicting pedestrian call), this isn't really common.

[@BalooUriza]

@@ljthefro I'm aware of what the FYA means and how rare it is for these to be set up in a safe way. Crosswalk calls should be filled as soon as safe, and must prevent a conflicting green or flashing yellow.

[@chloesibilla8199]

Hehehehe Siemens hehehehe that sounds like semens

[@aabsc]

Why 50 amps? Even if they were incandescent bulbs and all lit at once I don't see how it could possibly use anywhere near that yet they are probably LEDs and only a few are lit at once.