Answering YOUR Questions About Traffic Lights!! Pt. 1

[@seitzme]

Thanks for all the information! As a kid, the traffic light was my favorite thing on Mr. Roger’s Neighborhood, and I’ve been interested in them ever since.

[@kens.3729]

I’m sure there are a number of people have NO Idea what goes into Safely controlling an Intersection. Thanks for attempting to keep the General a public Safe.👍🙏

[@stephenfry-gdot]

I give OTJ training to fresh GDOT engineers as part of our PEDP, and most of them don't know. Granted they're only 1-2 years out of college, but you'd be surprised how many civil engineering courses one can take and how little time the university gives you to take them. Many times, they end up in this position having taken only structures or water resources or etc.

[@davidroddini1512]

I’d like to hear more about how a single cabinet is used to control more than one intersection (for example the two intersections of a diverging diamond interchange).

[@mike95826]

Do they ever synchronize two or more complete intersections and cabinets where the streets are close together to improve traffic slow? How would that be done? Some kind of data link?

[@amhainen]

Checkout "GUIDELINES FOR TIMING AND COORDINATING DIAMOND INTERCHANGES WITH ADJACENT TRAFFIC SIGNALS". Texas does a lot of diamond phasing. You can use a single controller or two separate controllers (older). If using two controllers, most use Time Based Coordination with careful clock synchronization. Older style is to have a "master" controller. Also can share information from controller to controller over fiber, radio, copper, etc.

[@Robertganca]

It would be cool if you could show us how a controller handles emergency vehicles.

[@23431]

Great Q&A session we appreciate it

[@aperson9495]

I've always been curious about what's inside traffic light cabinets and I've learned a bunch from your videos... One thing I haven't seen from what you've talked about is how are the phases determined? What determines Phase 1, Phase 2, etc? Is it based on cardinal directions, where Northbound would be Phase 1, westbound is Phase 2, Southbound is phase 3, eastbound is phase 4, and then left from the northbound direction is phase 5, etc, or something else?

[@stephenfry-gdot]

Google "NEMA Phase Numbers" and look at the images. That will answer your question.

[@jamesnichols7583]

Dude, I love your channel. I watch it even though I have no reason to I’d like learning about traffic signals and you are the teacher you are awesome.

[@cfwebdeveloper]

Set them to all 1's and watchout lol. Love the videos and learning

[@demal1010]

Can you tell us what the education and work experience qualifications requirements are for your position please?

[@ItsTheCostanza]

Hey Thanks, can’t wait for part 2

[@tlhIngan]

Also, you often need your laptop out when programming things - but you often need to wander away from it to test things. Do you just lock the cabinet with the laptop in it or do you just hope someone doesn't come around and swipe your stuff while you're working alone?

[@grayrabbit2211]

He is in Mississippi, not Detroit

[@BartlettTFD]

So interesting AND educational 👍👍

[@AddieDirectsTV]

How does it work when you have an intersection that is adjacent to a railroad track and you have to take into account trains interrupting the normal operation of the intersection. The other thing I’m curious about is how do (at least in my city) the busses can “talk” to the traffic signals to hold the green longer, or to get it to cut down the red signal’s time so that busses can stay on time.

[@jovetj]

The railroad detection equipment tells the traffic controller that there's a train coming, and the traffic controller adjusts the phases accordingly.

[@amhainen]

Check out "FHWA Preemption". ops.fhwa.dot.gov/publications/fhwahop08024/chapter9.htm

[@gordonshumway9675]

Thanks for answering my questions!

[@polypolyman]

Does your shop build the cabinets up from scratch or do you get the ready-to-install units from a supplier?

[@earlt911]

:: QUESTIONS :: Very informative video!! What education & training is needed to do all that highly technical work you do? Has any of those "boxes" or controllers messed up and caused a traffic crash?

[@amhainen]

Required: IMSA Work Zone IMSA Traffic Signal Technician I Additional: IMSA Traffic Signal Construction Technician II IMSA Traffic Signal Sr. Field Technician III IMSA Traffic Signal Inspector

[@earlt911]

@@amhainen WOW... that's a lot of classes.. I looked all those up.. www.imsasafety.org/wp-content/uploads/2024/02/IMSA_Signal_Cert_Brochure-1.pdf

[@Aerospace_EdC]

Here in NJ I noticed a new type of vehicle sensor is showing up. They are white rectangular devices, maybe 8" x 6" (tough to estimate size)mounted on the vertical part of the pole pointed down at the lane, do you know what type sensors these are ? Love the great content, lots of technology to run the traffic signals. I really hate those intersections that just run on a timer, no change in operation by vehicles.

[@stephenfry-gdot]

Based on your size description, those are microwave radar units. They are the most reliable form of detection, although video remains the easiest to configure and troubleshoot.

[@ckilo11]

i have a question that you may have already answered in a previous video: how do modern traffic lights work in regards to emergency vehicles that have their lights flashing? the reason for this is most of the time the traffic light changes to green before the emergency vehicle gets to the intersection. just wondering how that worked

[@tristonjamesyoung]

I love your videos how does the stop bars work

[@handle924]

What safeguards are there to prevent incorrect wiring / configuration?

[@jnelsoninjax]

I have a question: in my city they use the cameras on certain intersections, however, I am riding a mountain bike, and despite being in the lane, the camera does not seem to register that I am there. Is this likely due to the way they have the cameras programmed? I am going to try to call public works tomorrow and ask them about this as well.

[@kevinikola8003]

The other night, you were pulling new cables through the conduit. How deep into the street do those conduits go? Thank you!

[@TwistedForHire]

Question: how do you (or the intersection designers, or the equipment) keep the intersection safe? It seems like you could mispress a button, add an overlap to the wrong phase, and create a dangerous situation.

[@Manbearhorsepig]

In the controller cabinet there is an MMU or malfunction management unit. Its sole purpose is to prevent things like this happening. It won’t allow the phases to run if there is conflict.

[@haystack1739]

Could we plz get a name sir? Even a fake is fine. Love your content! Because of your knowledge I called in a malfunctioning light other day-they fixed it. Greetings from Nevada!

[@jrpaniagua1518]

Do you prefer working on span wire signal lights or mast arms?

[@nicknotes19]

Hey TLD! I've noticed you've been replacing a lot of doghouse signals with FYA signals. I've been seeing more FYA's pop up around my area as well. Could you explain why a lot of these seem to be getting switched out even though they appear to serve the same purpose? Thanks as always!

[@mobile_vic]

FYAs are becoming the standard because they resolve the 'yellow trap' issue with 5-section heads (dog houses). The yellow trap occurs when a driver turning left on a permissive gets a yellow light and expects oncoming traffic to stop...which sometimes doesn't happen and results in a collision. By having a separate signal head, the yellow for the turn can be timed in lead or lag and prevent that yellow trap.

[@jovetj]

@@mobile_vic Exactly!

[@kingpeachcolt]

Seems the "yellow trap" was already covered, but you may also notice that the FYA will sometimes go into the flashing yellow mode when a traditional doghouse section would stay red. I personally like the FYA much, much better.

[@fredunderhill7005]

Can you show how a RR crossing puts in a call? And what happens after the train leaves.

[@Manbearhorsepig]

Railroad intersections are interesting and unique. The intersection controller cabinet is wired to the railroad cabinet. The phasing is complicated but essentially there are additional phases and longer greens to ensure traffic does not back up on the tracks.

[@robertt8273]

Had no clue how complicated these cabinets are.

[@robertmailhos8159]

Well at least you are next to Lowe's so if you need anything to help with the job that you're doing

[@J3R3MY-Sigman]

Good afternoon!

[@crashedmonkey2589]

You might have answered this already, but I am curious if the cameras are better at picking up my sport bike than the older technology. Here in Phoenix, I have ridden through plenty of "dead reds" before riding to work early morning, but it seems like newer lights don't have that issue with me. Want to know if it's in my head or the newer cameras and lidars don't ignore me like the weight systems did.

[@jovetj]

0:40 Short answer: civil engineers.

[@Trafficlightdoctor]

@@jovetj for sure

[@stephenfry-gdot]

@@Trafficlightdoctor Am one, hahaha! 😁 Thanks for all you guys do! We can put a lot of ink on our plans, but it takes grit, grizzle, and long hours out in the field to actually get that ink to do something, hehehe. Cheers from the ATL!

[@stephenfry-gdot]

@@Trafficlightdoctor Regarding your preference for radar, I'm personally of the same mind. We still do a LOT of loops, though.

[@SledgeHammer43]

Welcome to D'Iberville, Mississippi

[@jeremykryder4880]

Hey what's the voltage on the signal conductors to the lights? And are the lights LEDs?

[@Liam_Wa]

Most Cabinets (95%) use 120VAC to the signal heads and Pedestrain Heads. The Newer intersections are starting to use LED's, but the older ones use incandescent bulbs.

[@Jonathan_O]

A little constructive criticism… record your computer and phone screens and edit into your videos. You make some great content, but trying to record you screen with a camera, no bueno. Keep up the good work 👊!

[@elementalkid82]

Have to ask a question about emergency signals , where I live every time an emergency vehicle approaches it gives them the green light.. but then it seems to reset the signal and you have to wait all over again .. do you know why it does this ? Thank you ! Love your content !!

[@Manbearhorsepig]

It’s for safety. When the emergency vehicle activates the preemption the controller will safely change to a green for them. It will then continue that phase until completion and the continue with the next phase in the sequence.

[@jovetj]

So how does the controller put he countdown number on the ped head? I never used to see problems with traffic signals until them count-down signals came along. Now I see them messed up ALL the time.

[@Tobyfaktor]

When you are at traffic light in a car lane on a bike will it turn green or will it stay red ?

[@grayrabbit2211]

Any Intelligent Traffic Systems / centrally managed systems? The signals in my area are synchronized and it made a huge difference.

[@tlhIngan]

What do you think of those people who hack the Polaris ped buttons? You see videos of them speaking other languages, or playing music because they got hacked. Obviously it couldn't hurt operation of the button, just an odd surprise for those crossing, but what do you think about that?

[@1613cundey2]

Does it affect the other lights if someone hits a pole and knocks it down?

[@Whoo711]

My question is: Is it "really super necessary" for intersections- especially left-turn lanes- to be set-up where, shortly after the light turns green, if you're "just not close enough" (but still approaching) to the main white line and/or sensors while driving- especially while avoiding going super-fast in the lane (safety)- the light oftentimes *turns red again* after, like... barely 5-10 seconds of green??? Surely another 10-15 seconds of green 'just in case' someone is *almost there* but not quite, would help in such a situation? Can the people who make or set traffic lights really "not fathom" this situation, which I imagine is fairly-common (at least, in my experience)? Seems kinda 'a waste' to make that "straggler" who, through no fault of their own, is "too late" (but could've easily made it in time, while the light was green, given just a bit more) and now has to wait another 2-3 minutes behind *another* red. Is there no way to have the usual sensor set-up *and* slightly-increase such a 'timer' for busy hours of the day?

[@demal1010]

I've read there's a sequence to pushing the walk sign button to get ahead in queue, is or was that ever true?

[@MikeF1189]

How much does a new m60 cost?

[@Liam_Wa]

Around 2-3 Thousand. They are'nt cheap lol.

[@cowboy777120031]

Does flashing your headlights at night cause the lights turned faster. And the other question is why does it take forever for the light to change when I’m on my motorcycle?

[@ralts6464]

Are 5 section traffic light more expensive than two 3 section lights and what would be the difference?

[@jovetj]

Yes

[@Ninjababy33]

I live in Toronto, Ontario, Canada, and I have a electric dirtbike that I ride on the road and when I’m at a intersection, trying to turn left sometimes the light just skips from green to red and then again and again even though it has a left turn signal could it be that I’m just not big enough I ride a surron light bee x 2024 edition

[@chippercutting1470]

Is there any traffic lights that can catch people running traffic lights

[@Manbearhorsepig]

Typically people are caught by independent red light running cameras. These are not directly attached to/ connected to the intersection controller. I don’t know of any equipment tied to the controller that catches people running lights. If it is out there it is not in my region.