He's way too educational for Discovery. Now, if he had an alien conspiracy theory about yellow lights and Elvis practicing civil engineering in his golden years, that's something Discovery would air.
No no no no no. Unless you know for certain that the signal is running either fixed time or you're approaching on the coordinated approach of a signal where the pedestrian phases are not toggled to actuated-coordinated, you should never do this. Watch your lights.
Here in Minnesota some highway traffic signals have these large yellow signs that say "prepare to stop when sign flashes" positioned several hundred feet before the intersection that gives you an early warning that the signal is about to change.
We have them up here in Canada too. A local pet peeve, though: They added two lights to a stretch of highway, the first set in each direction has warning lights, but the second does not, so you have to slam on your brakes sometimes. Since the lights are traffic activated, I learned to look for a vehicle waiting to cross instead.
Here in British Columbia, Canada these "prepare to stop when flashing" signs actually have to be installed on all roads with a speed limit of 70km/h (45mph) or higher. These signs often result in people gunning it to beat the light which is not great.
I have one like that I drive by daily. I live in a rural area outside of Surprise AZ off of the highway that connects Phoenix and Vegas. Its the first stoplight for about 5 miles and it’s about 3/4 mile from an interchange where it goes from 65mph to 40. It definitely helps, rarely see people running that light. On the opposite side heading away from the interchange people constantly run through on red because it goes from 40 to 65 immediately after that intersection.
Here in Macedonia, we have the green light blink 4 times before going to yellow, indicating that the yellow will turn soon and either grab the window or slow down even before yellow is on, which is a quirk of it's own :D
That's often called a "stale green" indication. I've seen it in Mexico and have been told that it was formerly used in parts of Canada. The usual explanation is that it's meant for pedestrian crossers to give them enough advance notice to clear the intersection or not to begin crossing too late in the cycle.
Same in Mexico, all of my cities traffic lights flash green before yellow. Its pretty neat as it gives you a heads up, but yellow doesn't last as much as it does in the USA. We know that if we see yellow and we're far away there's no way we're making it, but you can still make it with a flashing green.
The worst dilemma is when you're having to watch some fool near you and don't see the light ahead change from green to yellow. Therefore, you don't know how long it's already been yellow.
@Yazmeli Ayzol not always, you kinda need to know the signal beforehand to really know how long you have. some intersections near me don't turn yellow until the timer ticks to zero, while others only a couple miles away turn yellow at 5 seconds. some still don't have timers whatsoever
@Yazmeli Ayzol unfortunately this isn’t universally true as such case. Here in Phoenix AZ we have side streets that the crosswalk light will stay red while the traffic light remains green. Late at night we have crosswalks that count down to 0 and reset to walk. These odd traffic rules change when you visit sister cities near by
@Yazmeli Ayzol I'll echo what the others have already written: where I live, most pedestrian lights have countdowns on them and only about half of those count down to yellow, the others don't sync with anything else changing at the intersection so they cannot be relied on to gauge how much time there is left to a green light unless you know beforehand which is which.
A right turn in England has a much wider turn radius than a right turn in the US, because it's a cross-traffic turn that uses the whole intersection, instead of just being localized to one quadrant.
Gotta love drivers ed... they teach you all about why it's important to drive safe, but barely touch on how to even drive the stinking car in the first place safe or otherwise.
Did I miss something? Was he arguing the signal was too short or too long? Still not sure what relevance it has to his wife getting a ticket for going through red!
What the heck are self driving cars going to do? Maybe intersections should have a count down timer displayed. Most of our intersections have cross walk lights on the cross street with a count down timer. When the cross walk light turns red the traffic light turns yellow. I can see these lights way before I’m even in the yellow zone. If the cross walk light is green my light will remain green and I just keep on going.
@@Chris_at_Home In NJ the vast majority of lights I've encountered it either has no timer or the cross walk symbols doesn't change. As a manual driver it's annoying af, I'll shift up and I swear it's like it knows and then the stupid light changed to red. More annoying would be that our light don't go red yellow green like in the UK
@@Zadesniper When I moved here a little over 40 years ago the nearest stoplight was about 50 miles away. We could have WALK signals here because it is probably the new standard and most everything is new. Heck, the road I live on now wasn’t even here 15 years ago
@@Chris_at_Home To be more specific it's not necessarily that the crosswalk lights aren't there. It just simply doesn't work, I've never been able to understand it. Before getting a car walking around my old town was a gamble, you never really knew when or if the crosswalk lights would change and it's kind of more annoying now as a driver
@@uncletookie9102 Yeah. I use those all the time at smaller intersections so I can start making a decision. Seems logical to add them to major ones where you don't normally cross.
Here we had timer on traffic light back then. But turn out, installed timer just make crossing even worse. Uncertainty make people driving slower. With timer, you will see people start speeding like crazy when crossing especially at the last seconds. Also timer can distract you instead of looking the vehicle in front of you. And that over speeding behaviour on crossing make emergency vehicles really hard to cross that intersection. So, nowadays after some study, that timer are removed from all intersection.
They have those in Belarus and Rwanda, and I really wish they’d install those in my German city as well, however, it seems that in my city the lights are calibrated to turn yellow the very moment you arrive from the previous light, likely to increase fuel consumption (fuel is taxed very highly in Germany). Installing timers would allow people to let go of the gas sooner and burn less gas, thus reducing the tax income, so I don’t see that happening any time soon.
What I recommend traffic engineers do is calculate what the decision zone is at the speed limit, and the solid white line should start where the decision zone is. So if you’re past the solid white lane and it’s yellow, go.
It would be expense but LEDs are cheap enough these days that they could install a bunch of lights in the road that change from green to yellow to red with the flow of traffic to indicate to drivers essentially what you are saying here. Maybe not at all intersections but just one as a proof of concept.
Problem is that only works if the traffic is flowing at the speed limit. If it's flowing slower, the light will be red long before they get there, and people will say "Well, I was in the solid white zone when it turned yellow, so I just kept going". Clearly common sense should apply but... it's not so common.
Given the responses here, how about two things. First, know that it is a zone. It is not a single point (laden truck vs. ordinary sedan), so the indicator has to have range to it. Second, the demarcation is done after the fact. Determine the marks based on the behavior of drivers themselves rather than formula. Where I first learned to drive, speed limits were determined by survey. The county used the assumption that 80% of drivers do so safely. So they monitored roads and used the 80th percentile (rounded) to determine posted limits. Do the same for indicating the decision zone for a light.
I find the advance yellow lights saying "prepare to stop when lights flashing" located some distance ahead of the traffic lights really helpful in determining whether you should stop or not. They are widely used on high speed routes here in Canada.
That truck was running an empty trailer, without weight the wheels can lock up under even moderate braking. Stopping empty takes longer at times than when loaded.
@@ShainAndrews Except physics also has to remember to account for all the various parts involved...they're all moving, and they're all designed to operate under certain conditions. In this case, they're designed to operate when at the recommended carry weight. When it's well under that weight...well, that weight exerts a known pressure on the wheels, and when it's absent, it can cause unexpected results. There's a similar thing that happens when a pick-up truck starts moving from a standing stop at a light while pointed uphill. If the box at the back is empty, that truck can slide back or have trouble with traction. After all, it's engineered to expect a lot more weight.
@Evil Me That's the retort a keyboard warrior uses. Like to a T response. One wheel locked up. One misadjusted brake. Good reason your alleged engineering didn't pan out, I have concerns about your truck driving career as well... You can redeem yourself. Provide the formula that supports your position.
When I learned how to drive on the West Coast, that's what I was taught as well. Approaching an intersection with a traffic signal, pick a point well in advance. If the light turns yellow before I reach that point, brake to a stop. If you're past that point when the light turns yellow, keep going. Also, glance quickly in the rearview mirror, and see if anyone's tailgating you.
@@NYRavage Man imagine if someone is tailgating you in the dillema zone and a car is oncoming and you dont have a space to swerve left or right or enough acceleration to avoid the tbone. Some final destination shit.
@@remingtonrojas then go through. It takes a few seconds from when your light turns red to when the intersecting traffic's light turns green, so you'll be fine.
@@NYRavage Spot on. The only other issues are, what’s behind you, and what’s the weather like? It’s often better to avoid a last minute ‘emergency stop’, especially if you’re driving a newish one with built-in emergency braking (sometimes known as ‘crash prevention’ - at least, not in front. It can’t prevent it on the tail)!
@@JiminyClarkson Which is exactly why I feel there should be a 1 to 1.5 second grace period before a red light camera should activate. Someone with good intentions who believe they had time to safely proceed through on a sudden yellow should not be penalized that way.
Holy smokes, someone talking about signals that actually knows something about them! Looking forward to your next video. My favorite thing about being a traffic engineer is that its far less engineering than pretty much all other forms of engineering, and more a study of human behavior+engineering. I will say, the Oregon right turn yellow case should come with the permissive vs prohibited yellow light law. I remember reading up on this and thinking 'what on earth is he talking about' only to realize he was in a prohibited yellow state. I think for permissive yellow light states, the old kinematic equation with PRT accounted for works just fine. Heck, I've even shortened left turn yellows by a half second because people are slowing down already (but typically have longer all red's).
If you’re interested in traffic lights watch this video about traffic lights in the Netherlands: th-cam.com/video/knbVWXzL4-4/w-d-xo.html . They are even more complicated! Btw right turns should have it’s own lane and light at major junctions (only if there is enough space for multiple lanes) like we do here in the Netherlands. It speeds up the flow of traffic and is much safer.
@@ns-fan9319 in ny, its a little known rule that you must stop at a red light turn light separate from the main light i think. You cant turn right on a red arrow.
Honestly, the best solution is to update traffic lights with a countdown timer (ideally, both green and red light - green increases safety, red increases throughput) with addition of green blinking. Then add a yellow according to the kinematic equation. That way, drivers will have enough time to start contemplating about their distance to the intersection. In places where countdown update is too expensive, green blinking alone can be implemented (this should be relatively cheap). In places where the speed is too high (and thus the countdown display would have to be large to be seen from afar) or there is a bent (and thus the traffic lights cannot be seen from afar), there could be a "pre-signal" installed (i.e., prepare to stop when blinking).
The blinking hand and/or the countdown on the pedestrian light for the cross street to your right is usually a good indicator that you will have yellow.
My mom taught me that when I was a kid in a car seat. I’m 44 now. She was a public bus driver for the county. Those have become more unpredictable throughout the years I’ve noticed.
I do the same thing, but usually as a biker. It's easier for me to stop when I see a yellow from a distance obviously, but I am in the actual intersection for much longer than cars. And busier, more car centric streets usually have larger intersections so this little indicator does a lot for me. Since even going on a green can end up with me being in the intersection at a red at the end, I'll just start coasting even though the light is green if timer is low enough.
Rob this is awesome. Thanks for taking some time on this subject! My skin crawls seeing people scoot thru reds at high speeds. Almost saw a guy get killed in a crosswalk due to this sort of speeding thru. -Former class A instructor here.
I've noticed two things I can use as relatively-reliable indicators of yellow light time: 1) Pedestrian crossing indicators, especially when a countdown timer is present 2) The length of the left-turn lane. For the latter, if I'm in my own straight-thru lane and past the beginning of the left turn lane when the light changes to yellow, I'm good to keep going. But if it turns yellow before I pass the start of the left turn lane, the light's almost certain to be red before I enter the intersection. Neither is infallible or fool-proof, but they work probably 80% of the time or more.
I like the intersections that have the flashing walk signals and even better with the ones that have the countdown to how many seconds till the yellow. So as your approach the intersection you can see the flashing walk signal and give yourself a little bit of a advantage in calculating the decision zone. But as drivers we get very good at calculating that in your head as long as you're paying attention and not being distracted.
Can we just take a moment to talk about how good this guys videos are? Like the production is really nice and interesting. He deserves more subscribers!
I was just going to say that the frustrating part is that every yellow light has a different time length. Even in the same city or neighborhood. 🤦🏾♂️ There's no way to be able to be prepared unless you travel that way all time.
To be fair the only calculation you should have to make (and if the lights were all timed different but using the equation described it would be fine) is can I stop in time to stop behind the white line. If once you see the yellow it's impossible for you to come safely to a stop behind the line, then you go, if you can then you do. Of course, since many lights are made to make money on the red light cameras or tickets etc... you can't always trust that rule.
@@TenOfZero1 and if the yellow light only lasts 2 seconds then that calculation is wrong. This happens all the time. Sometimes its 3 seconds sometimes 4.5 seconds. Even lights that I take all the time will change length sometimes. Bigger intersections you would assume last longer and some don't. Its always a variation.
Yeah just like a lot of other things too. Like in cities when lanes suddenly force you to turn and theres no way you'd be prepared for it unless you've been there before or using a gps. Texas actually uses square lane markers for this and I'd like to see every other state take notes on the way texas handles their roads and traffic laws
@@AR-xs9uk I think you missed the point of that reply. Pretend the yellow light doesn't exist for a second (like it takes 0sec). The idea is, if the light turns red on you approaching, can you safely stop before the white line? If yes, do stop. If no, just go through (but don't worry it's not actually red it was yellow, and that is why yellows exist anyway). So tldr, the yellow time shouldn't be a factor in your reaction.
@@reububble i think you misunderstood my point as well. It doesn't ever cause me that much stress its just an inconvenience because its always different.
When I was a kid back in the 50's and 60's, we were visiting California (Los Angeles). The traffic signals not only had lights, but little arms that would raise and lower depending on which light was on. I'm not sure but I think the lights went from green to red.......no yellow. Bare in mind this was 60 plus years ago. Great video as usual. Thanks Bob
I've been through that intersection in Beaverton plenty of times in my many visits to Hillsborough/Beaverton between 2005-2012. Usually we rode around with family/friends so I didn't notice it much, but did notice when we stopped quickly or accelerated heavy through the yellow lights. When I was driving on my own, getting lost frequently during the pre-cellphone days of google maps, I'd frequently come across yellow lights on backroads on ~30mph roads that seemed to only last 1.5-2 seconds max, with no delay between the changing cross traffic light turning green. I always anticipated a red-light ticket in the mail after our trips down to Oregon (4-5 per year) but never got one.
Whats happening is, you are already close to the light, already slowing down to turn right, and the yello comes on. You have the same problem faster drivers have, which is, you can't slow down enough to stop at the light. But, because you drive a lot slower, it takes you a lot longer to go thru the intersection than those going straight thru it at much higher speeds
@@argh523 If you are already slowing down to turn right and the light turns yellow, you will ALREADY have enough time to stop or turn no matter what without any tweaks to light timing for turns. The distance you need to travel is much shorter when you're turning right AND due to the fact you're slow, the stopping distance is also far less.
I had this happen a couple years ago...was driving through a yellow when someone in the opposite direction left turn lane decided to try to beat the light. He turned left right in front of me and wasn't even CLOSE to making it. I hit him essentially head on going 45-ish. Even with a seatbelt and airbag, I had to get 8 staples in my head and had a crazy concussion. (I kinda felt like I had a cold for about a week...it was really weird.) Ended up getting a decent insurance settlement that funded my new business, though...so it wasn't a total loss, I guess. Be careful with yellow lights!!
@@nonionbeezness Since it's only really problematic on high speed road, here in Quebec, Canada we have a sign like 250-500m before the intersection saying "Prepare to stop" with flashing light.
I live about 10 minutes from the Hall - Scholl's Ferry intersection in Beaverton, and it is truly awful. The issue we had a few years ago was with Beaverton intentionally using shorter yellow light intervals than surrounding cities as a way to increase revenue, and changing the timing without notifying the public. With so many people commuting to and from Portland from Hillsboro, Forest Grove, and Tigard, they knew it would make money. Beaverton is also notorious for its insane amount of yellow-light cameras, lower than normal speed limits, and high patrol rates, to the point where people that live here actively drive around Beaverton if possible.
RIP. Hillsboro is a nice area, but the traffic is terrible! How can they use 217 going there and its 2 lanes??? Backed up to I5 most of the time so I just never go up there anymore
Some places near me, in Sydney, Australia, have these types of warning. They are used when the lights are obscured - eg beyond the crest of a hill, or just past a rail underpass.
Those are really nice on those limited-access divided rural highways with 50-60 mph speed limits that feel kinda like a freeway with driveways, some side roads, and some intersections with traffic lights.
Well, maybe I'm a little bit late. In Mexico the system we use is also red yellow and green lights but just a few seconds before the green light changes to yellow, it starts to flicker to warn drivers to be aware of the light change
Thanks. I really enjoy watching your videos. For me, it is very interesting to see how the same problem is handled different in Europe and the USA. Here in Germany there is a law, how long the yellow phase has to be. 3s if the speed limit is 50 km/h 4s if the speed limit is 60 km/h 5s if the speed limit is 70 km/h
@0:57; There actually was a time when there weren't yellow lights, but in place was that both the green and red were on at the same time before the green light went out and it was red.
red light camera contracts have been released that show the contract requires shortening the yellow to make the red light cameras more profitable to both the contractor and the city.
if they want red light revenue, why not time travel back to 1920 and get rid of the yellow light. personally i would have machine gun enforced traffic lights
The only car accident I've ever been in was a provisional driver panicking at a yellow and braked into the intersection. I was following the flow of traffic so kept going before I saw them slam on the breaks...
@@nut6080 dude ever heard of different kinds of brakes? It doesn't matter how fast or slow you are going if your car don't have good brakes or the car infront of them have better brakes you're going to rear end them. Stop being so quick to judge.
On the subject of yellow light timing for turns, I immediately wondered how it was that during my mumble-mumble decades of driving experience, I'd never encountered a situation where I'd overrun the white line on red when turning. Then it become clear - if your plan is to maintain speed until maximum safe braking will get you over the white line at 15 mph, then if the lights change at an unfortunate moment for you, you will inevitably cross the line on red. So it's a bad plan. There's no compelling reason to drive that way. All that's required is to slow down more gradually starting from a greater distance. Then, if the lights chance at any point on your approach to the junction, you'll either be able to stop before the white line, or will cross it before the lights go red. There are no grounds to for changing the yellow light timing just to cater for needlessly lead-footed drivers.
In some countries, (UAE for example) the light flashes yellow on and off before going solid yellow. Gives you a bit longer on yellow and makes the whole thing easier to gauge. Back in my home country, England, you also get a period before it goes green again of Red+Yellow lit at the same time. This is great because it gives you a couple of seconds to get ready to set off again. Sort of a "ready, set, go". Perfect for over there as most cars (80%+) are stick shift and this gives you a couple of seconds to clutch in and shift before it goes green. I drive a stick shift here in the US, and very much miss the UK style of lights.
I'm a truck driver and I anticipate a long lit green light to change before I get to it. Now there are occasions where it changes at a point where I can not safely stop. Now with my truck often at a weight of about 75,000-80,000lbs I cant, so I if I know I'm gonna run it, I get on my Horn and try to atleast warn, however I always try to slow down in anticipation of it turning yellow.
There's another aspect of the formula: Taking into account there composition of vehicles in that location, and their stopping distances / weights (which affects the incline calculation part). So they'd need a weighted average of the stopping distance and incline gravity. They'd also need the vehicle condition weighted average, as vehicles in worse condition generally have worse brakes and hence longer stopping distances too.
I recently got a ticket in NY because I was used to the yellow light length of rural NJ. I think a good issue to bring up is the consistency of yellow light duration.
Traffic lights in my city Medellin start flashing before turning yellow, specially because we have lots of red light cameras so you may get a ticket if the traffic signal turns red while you’re in the intersection.
I'd just love to see a color-coded line at intersections that tells you when you've passed the "recommended " commit line for a car with mediocre brakes going 5 over, at least on intersections without too much other visual noise.
Maybe just adding a second line like you have for the stopping line? Would be a easy an elegant solution. The only problem with this is that if something happens because someone followed that recommendation the city is getting sued.
@@Arjay404 yeah. My thought would be some inconspicuous blue or purple line that doesn't distract you, but if you know it's there you can use it. I wouldn't want it to be as conspicuous as the lines that direct traffic.
Some of the lights around me are timed to go yellow when the walk indicator ticks down to zero. This is useful in knowing ahead of time if the yellow light is coming. Not all lights are set this way though.
I have found in most cases the length of the solid white line separating the left turning lanes is a reliable indicator of where the dilemma zone is if traveling at the speed limit. I do not know if this is intentional or coincidence.
I dunno about other states, but I remember South Dakota would often paint solid white lines approaching an intersection that vary in length depending on the expected speed of the road. I realized they were useful to know if you had time to clear a yellow or if you needed to slow down.
You put 2 segments together and you have your own cable show! I love the amount of effort you put into these things! You just made learning about YELLOW LIGHTS interesting! Awesome job Rob!!
I use solid lines as the indicator at an intersection to determine if I should brake or continue. Seems incredibly common in Canada. Inside solid - drive through the yellow. Before the solid, come to a stop.
You can't stop people from speeding no matter what. Not without taking away a LOT of control from the driver, and believe me, you don't want to do that. So the safest idea is to simply accomodate people who drive about 5-10 mph over the posted limit (which is like, 90-95 percent of drivers on the road) and give them more time to make a safe and informed decision.
@@cameraredeye3115 It's only common because you are accommodating for it. I can assure you the situation is very different over here in western Europe. For starters, the infrastructure is designed in a way that is appropriate for the local speed limit; no airport taxiways in suburbs. If you lower the speed limit, take appropriate measure such as making the lanes narrower, or installing bottlenecks or speed bumps, whichever is appropriate for the desired speed. On freeways, you can easily place average speed cameras to automate enforcement of the speed limit. These investments immediately pay off. There won't be fewer collisions per se, but survivability improves as speed decreases, and there will also be less material damage. This means lower insurance premiums for everyone, apart from the obvious advantages of better mileage and less wear on the brakes. America never fails to baffle me. You MUST park on the right or else. You can ONLY cross at a crosswalk. Passengers MUST exit kerbside. Oh, and of course it's okay to speed a little bit, everyone does it. Truly mindblowing.
It would be interesting to hear you talk about Baltimore's infamous unfinished Interstate 170, aka "The Highway To Nowhere". Having driven on it myself and seen all the constant bickering about it in the newspapers, it would be cool to get an outsider's perspective on it.
There are 2 youtube channels i absolutely love but the frequency of videos is just not enough to satisfy me. This is one of them. (The other is Casual Navigation). When i win the lottery I am dumping thousands of dollars on this channel for more videos. :)
On highway 89 in utah they added yellow flashing light's an 1/8 mile before the stop light, the flashing yellow lights came on before the yellow on the traffic signal. This road has a 50 mph speed limit and the dilemma zone was huge before they installed the extra lights.
These uploads are so good. I've never knew I could care about what happens behind the scenes in traffic. Goes to show that what we typically see is only a fraction of what's going on. This applies to just about everything.
In the case where the truck couldn’t stop but the car could stop, the truck was too close to the car. That’s not a yellow light problem, it’s a tailgating problem.
In Australia, or at least my state in Australia, traffic lights will have a "buffer time" in which all lights will be red at the same time for a couple of seconds to allow for cars trying to beat the yellow light. You will still be booked for going through a red light but at least you don't get in an accident
This is also why you should always check for traffic before entering the intersection on a fresh green! I'd imagine before long traffic engines will be using machine learning to decide how long to make the yellow at each intersection.
7:55, that's CRAZY that they use 1 second. In aviation, they use 2 seconds, and if you watch how long it takes for the average car to move at a green, it's about 2 seconds per car. Count next time you're queued at a light. It's almost perfect.
Another issue is the initial reaction of a driver to hit the breaks then relise they wont stop in time (or vehical behind them etc) so they have to continue but at a slower pace
Great to see Pickup truck Drivers in the States just drive like the equivalent here in Australia to our Ute drivers. They are all cut from the same cloth by the looks of it.
In Austria, the green light starts blinking before it turns yellow giving the drivers a warning and therefore closing the dilemma zone. Some lights in China have timers attached to the green light so you can time yourself, and decide if you can make it.
Rob called the dilemma zone and "invisible line" but couldn't they just paint them on the road? One for cars, one for trucks. If you see the light turn yellow and have not yet passed the line, you stop. Even if you were to make it, they could make passing the limit line on a yellow if you passed the dilemma line while it was yellow an infraction. This would even be compatible with red light cameras.
Not a perfect solution since times are different depending on the light, but I wonder if it would be plausible for engineers to determine the appropriate time on the yellow light and then use that information to have road crews paint a line across the road to denote who should stop and who has time to continue. If you're behind the line when the light turns yellow, you know you don't have time and must stop. If you're inside the line, you have time to continue through the yellow light.
“In 1980 the federal Highway administration found that...” We are not in 1980 anymore. Population size and automobile technology improvements would greatly change that study. Obsolete!
One of the problems with the formula is that it has no input for condition of the road such as when it is raining or snowing. A 4 second yellow might be barely enough time to stop when road is dry but is way too short when road is wet.
![Stroads are Ugly, Expensive, and Dangerous (and they're everywhere) [ST05]](http://i.ytimg.com/vi/ORzNZUeUHAM/mqdefault.jpg)
![เปิดบ้าน พี่ตูน Bodyslam หลังใหม่คนแรก ที่ภูเก็ต l [Nickynachat]](http://i.ytimg.com/vi/flFwcmyDQSk/mqdefault.jpg)
It’s funny when you go through a yellow light thinking “I barely made that” then to look in your rear view mirror you see three cars behind you.
Makes me feel less guilty! Lol
I think "phew I'm not the only one to get a ticket, cop needs to stop one of us and it ain't gonna be me!" As I zoom off.
lmao
When I pass a yellow light, I purposely make sure no one behind me trails a red light
@@onemustypickle ikr!
The production quality is so good, this should be like a show on discovery channel or discovery velocity or something
Yes. This reminds me of those videos we would watch in science or health
@@morr2010 only these ones are actually good!
He's way too educational for Discovery. Now, if he had an alien conspiracy theory about yellow lights and Elvis practicing civil engineering in his golden years, that's something Discovery would air.
It's way too good for Discovery Channel.
Slight overediting IMO. You see it a lot when channels are becoming successful and trying to find the right balance.
Honestly, I find the pedestrian countdown timers to be way more useful than yellow lights.
That's exactly how I time the lights too.
@@tariqshabazz3477 If I can see the pedestrian crossing time I use that as help determining to stop or press the gas pedal.
But you get the light that hits zero and stays green.
@@lawnmowerdude There are a few ( not many) around where I live that do that.
No no no no no. Unless you know for certain that the signal is running either fixed time or you're approaching on the coordinated approach of a signal where the pedestrian phases are not toggled to actuated-coordinated, you should never do this. Watch your lights.
Here in Minnesota some highway traffic signals have these large yellow signs that say "prepare to stop when sign flashes" positioned several hundred feet before the intersection that gives you an early warning that the signal is about to change.
We have them up here in Canada too. A local pet peeve, though: They added two lights to a stretch of highway, the first set in each direction has warning lights, but the second does not, so you have to slam on your brakes sometimes.
Since the lights are traffic activated, I learned to look for a vehicle waiting to cross instead.
We have one of those near where I live, and if you see it flashing, you'd better stop.
Yeah I live there too
Here in British Columbia, Canada these "prepare to stop when flashing" signs actually have to be installed on all roads with a speed limit of 70km/h (45mph) or higher. These signs often result in people gunning it to beat the light which is not great.
I have one like that I drive by daily. I live in a rural area outside of Surprise AZ off of the highway that connects Phoenix and Vegas. Its the first stoplight for about 5 miles and it’s about 3/4 mile from an interchange where it goes from 65mph to 40. It definitely helps, rarely see people running that light. On the opposite side heading away from the interchange people constantly run through on red because it goes from 40 to 65 immediately after that intersection.
Here in Macedonia, we have the green light blink 4 times before going to yellow, indicating that the yellow will turn soon and either grab the window or slow down even before yellow is on, which is a quirk of it's own :D
I think I noticed Tijuana had something similar. That would be a good pre yellow feature here in the states
@@craigcarter400 It really is, we also had a system previous to this one with timers, but everyone seemed to use them as countdowns for "racing" :)
That's often called a "stale green" indication. I've seen it in Mexico and have been told that it was formerly used in parts of Canada. The usual explanation is that it's meant for pedestrian crossers to give them enough advance notice to clear the intersection or not to begin crossing too late in the cycle.
here in the philippines, some cities have traffic lights equipped with timers so drivers can quickly judge whether to stop or not
Same in Mexico, all of my cities traffic lights flash green before yellow. Its pretty neat as it gives you a heads up, but yellow doesn't last as much as it does in the USA. We know that if we see yellow and we're far away there's no way we're making it, but you can still make it with a flashing green.
The worst dilemma is when you're having to watch some fool near you and don't see the light ahead change from green to yellow. Therefore, you don't know how long it's already been yellow.
@Yazmeli Ayzol not always, you kinda need to know the signal beforehand to really know how long you have. some intersections near me don't turn yellow until the timer ticks to zero, while others only a couple miles away turn yellow at 5 seconds. some still don't have timers whatsoever
@Yazmeli Ayzol unfortunately this isn’t universally true as such case. Here in Phoenix AZ we have side streets that the crosswalk light will stay red while the traffic light remains green. Late at night we have crosswalks that count down to 0 and reset to walk. These odd traffic rules change when you visit sister cities near by
@Yazmeli Ayzol I'll echo what the others have already written: where I live, most pedestrian lights have countdowns on them and only about half of those count down to yellow, the others don't sync with anything else changing at the intersection so they cannot be relied on to gauge how much time there is left to a green light unless you know beforehand which is which.
Always watch the road ahead. Don't worry about the fool near you.
@Yazmeli Ayzol 1 second warning is not enough time to safely judge if you can stop or not
Shout out to the Oregon board of engineers and surveyors for keeping the United States stuck in the 20th century.
I tried to send OSBEELs a zip file once, they couldn't open it.
Honestly most states would have acted the same way. I'm proud that this guy came from my state though.
Not going to lie, thats good for 98% of the state. Only Portland Metro area needs some updated stuff
dude won a constitutional case on a yellow light kerfuffle. that’s amazing.
@@rileyesmay It's really not. Proper light setups benefits anywhere with roads.
11:08 "nobody makes a right turn at 47mph" **McDonald's drive thru in England flashbacks**
Oh god
A right turn in England has a much wider turn radius than a right turn in the US, because it's a cross-traffic turn that uses the whole intersection, instead of just being localized to one quadrant.
THIS SHOULD BE REQUIRED VIEWING FOR EVERY DRIVERS ED CLASS!!
SUPERLIKE THIS
I agree!
Gotta love drivers ed... they teach you all about why it's important to drive safe, but barely touch on how to even drive the stinking car in the first place safe or otherwise.
@@EpicDrew15 Drivers ed isn't required? Where do you live?
Ikr they should make drivers watch this as standard!
The engineer story, I've been following it for a while. Good job for hitting all the points. 🤞✌
Did I miss something? Was he arguing the signal was too short or too long? Still not sure what relevance it has to his wife getting a ticket for going through red!
What the heck are self driving cars going to do? Maybe intersections should have a count down timer displayed. Most of our intersections have cross walk lights on the cross street with a count down timer. When the cross walk light turns red the traffic light turns yellow. I can see these lights way before I’m even in the yellow zone. If the cross walk light is green my light will remain green and I just keep on going.
@@Chris_at_Home In NJ the vast majority of lights I've encountered it either has no timer or the cross walk symbols doesn't change. As a manual driver it's annoying af, I'll shift up and I swear it's like it knows and then the stupid light changed to red. More annoying would be that our light don't go red yellow green like in the UK
@@Zadesniper When I moved here a little over 40 years ago the nearest stoplight was about 50 miles away. We could have WALK signals here because it is probably the new standard and most everything is new. Heck, the road I live on now wasn’t even here 15 years ago
@@Chris_at_Home To be more specific it's not necessarily that the crosswalk lights aren't there. It just simply doesn't work, I've never been able to understand it. Before getting a car walking around my old town was a gamble, you never really knew when or if the crosswalk lights would change and it's kind of more annoying now as a driver
Those drone shots were great!
I'm so jelly, I want a drone so bad.
Lambs canyon!
Those are drone shots, a bird stole his camera.
@@emmess7780 lol
2:33 why 🤣
For major intersections, I wish that there was a timer so you can start making a decision earlier.
Or maybe have the traffic light have only 2 lights. The red light starts out yellow and more and more of it becomes red.
@@williamhuang8309 that's confusing
@@uncletookie9102 Yeah. I use those all the time at smaller intersections so I can start making a decision. Seems logical to add them to major ones where you don't normally cross.
Here we had timer on traffic light back then. But turn out, installed timer just make crossing even worse. Uncertainty make people driving slower. With timer, you will see people start speeding like crazy when crossing especially at the last seconds. Also timer can distract you instead of looking the vehicle in front of you. And that over speeding behaviour on crossing make emergency vehicles really hard to cross that intersection. So, nowadays after some study, that timer are removed from all intersection.
They have those in Belarus and Rwanda, and I really wish they’d install those in my German city as well, however, it seems that in my city the lights are calibrated to turn yellow the very moment you arrive from the previous light, likely to increase fuel consumption (fuel is taxed very highly in Germany). Installing timers would allow people to let go of the gas sooner and burn less gas, thus reducing the tax income, so I don’t see that happening any time soon.
I’ve read about these things before, but this channel helps it make sense
What I recommend traffic engineers do is calculate what the decision zone is at the speed limit, and the solid white line should start where the decision zone is. So if you’re past the solid white lane and it’s yellow, go.
Interesting idea, but some roads need to allow lane changes into that expanded solid line area
It would be expense but LEDs are cheap enough these days that they could install a bunch of lights in the road that change from green to yellow to red with the flow of traffic to indicate to drivers essentially what you are saying here. Maybe not at all intersections but just one as a proof of concept.
Problem is that only works if the traffic is flowing at the speed limit. If it's flowing slower, the light will be red long before they get there, and people will say "Well, I was in the solid white zone when it turned yellow, so I just kept going". Clearly common sense should apply but... it's not so common.
Given the responses here, how about two things.
First, know that it is a zone. It is not a single point (laden truck vs. ordinary sedan), so the indicator has to have range to it.
Second, the demarcation is done after the fact. Determine the marks based on the behavior of drivers themselves rather than formula. Where I first learned to drive, speed limits were determined by survey. The county used the assumption that 80% of drivers do so safely. So they monitored roads and used the 80th percentile (rounded) to determine posted limits. Do the same for indicating the decision zone for a light.
That's what is done in my city. But they use 3 sets of arrows to indicate the zone.
We all know the "other" part of that poll really means "picked at random a number that looked nice"
Is it bad that you do a better job explaining traffic engineering concepts than my professor did 😅?
I find the advance yellow lights saying "prepare to stop when lights flashing" located some distance ahead of the traffic lights really helpful in determining whether you should stop or not. They are widely used on high speed routes here in Canada.
I'm 15 seconds in and laughed way too loud on the football commentary joke at the beginning.
That truck was running an empty trailer, without weight the wheels can lock up under even moderate braking. Stopping empty takes longer at times than when loaded.
"Stopping empty takes longer at times than when loaded." Physics... well physics says a very different story.
@@ShainAndrews lol maybe if your definition of physics excludes friction.
@@ShainAndrews Except physics also has to remember to account for all the various parts involved...they're all moving, and they're all designed to operate under certain conditions. In this case, they're designed to operate when at the recommended carry weight. When it's well under that weight...well, that weight exerts a known pressure on the wheels, and when it's absent, it can cause unexpected results.
There's a similar thing that happens when a pick-up truck starts moving from a standing stop at a light while pointed uphill. If the box at the back is empty, that truck can slide back or have trouble with traction. After all, it's engineered to expect a lot more weight.
@Evil Me That's the retort a keyboard warrior uses. Like to a T response. One wheel locked up. One misadjusted brake. Good reason your alleged engineering didn't pan out, I have concerns about your truck driving career as well... You can redeem yourself. Provide the formula that supports your position.
@@ShainAndrews If you knew how drum brakes work you wouldn't have made this comment.
I’m a college sophomore studying Civil Engineering. These videos make me excited and hope that I can work to improve these issues! Great content!
Please remember the pedestrians when you work. Not everyone can drive.
Are you graduating soon?
Cool to see my hometown used here, as someone who drives by the dump a lot I can attest to that stoplight, it’s a doozy.
In every traffic light I use an imaginary reference point like a sign or lamp post and use it for a point of braking or no return.
When I learned how to drive on the West Coast, that's what I was taught as well. Approaching an intersection with a traffic signal, pick a point well in advance. If the light turns yellow before I reach that point, brake to a stop. If you're past that point when the light turns yellow, keep going. Also, glance quickly in the rearview mirror, and see if anyone's tailgating you.
@@NYRavage Man imagine if someone is tailgating you in the dillema zone and a car is oncoming and you dont have a space to swerve left or right or enough acceleration to avoid the tbone. Some final destination shit.
@@remingtonrojas then go through. It takes a few seconds from when your light turns red to when the intersecting traffic's light turns green, so you'll be fine.
@@NYRavage Spot on. The only other issues are, what’s behind you, and what’s the weather like? It’s often better to avoid a last minute ‘emergency stop’, especially if you’re driving a newish one with built-in emergency braking (sometimes known as ‘crash prevention’ - at least, not in front. It can’t prevent it on the tail)!
@@JiminyClarkson Which is exactly why I feel there should be a 1 to 1.5 second grace period before a red light camera should activate. Someone with good intentions who believe they had time to safely proceed through on a sudden yellow should not be penalized that way.
When getting my CDL they taught us to cover the brake pedal when approaching a stale green. It really helps eliminate the last minute breaking.
Holy smokes, someone talking about signals that actually knows something about them!
Looking forward to your next video. My favorite thing about being a traffic engineer is that its far less engineering than pretty much all other forms of engineering, and more a study of human behavior+engineering.
I will say, the Oregon right turn yellow case should come with the permissive vs prohibited yellow light law. I remember reading up on this and thinking 'what on earth is he talking about' only to realize he was in a prohibited yellow state. I think for permissive yellow light states, the old kinematic equation with PRT accounted for works just fine. Heck, I've even shortened left turn yellows by a half second because people are slowing down already (but typically have longer all red's).
I was also confused about that case until you mentioned Oregon being a prohibited yellow state. Makes sense now!
If you’re interested in traffic lights watch this video about traffic lights in the Netherlands: th-cam.com/video/knbVWXzL4-4/w-d-xo.html . They are even more complicated! Btw right turns should have it’s own lane and light at major junctions (only if there is enough space for multiple lanes) like we do here in the Netherlands. It speeds up the flow of traffic and is much safer.
We have right turn lanes same as any other country
@@gg2847 So why don’t give them a separate light? It gives a clear turn for cars and a clear crossing for cyclists and pedestrians.
Not Just Bikes and Road Guy Rob are the two best channels on TH-cam, change my mind
@@ns-fan9319 in ny, its a little known rule that you must stop at a red light turn light separate from the main light i think. You cant turn right on a red arrow.
@@KoJesko This is only in NYC. I almost got ran over by an idiot making a right on red and he wondered why I was yelling at him.
Honestly, the best solution is to update traffic lights with a countdown timer (ideally, both green and red light - green increases safety, red increases throughput) with addition of green blinking. Then add a yellow according to the kinematic equation. That way, drivers will have enough time to start contemplating about their distance to the intersection.
In places where countdown update is too expensive, green blinking alone can be implemented (this should be relatively cheap). In places where the speed is too high (and thus the countdown display would have to be large to be seen from afar) or there is a bent (and thus the traffic lights cannot be seen from afar), there could be a "pre-signal" installed (i.e., prepare to stop when blinking).
The blinking hand and/or the countdown on the pedestrian light for the cross street to your right is usually a good indicator that you will have yellow.
I feel like I'm the only person I know who watches for that! It's a passable substitute for countdown lights in certain European countries.
My mom taught me that when I was a kid in a car seat. I’m 44 now. She was a public bus driver for the county. Those have become more unpredictable throughout the years I’ve noticed.
I do the same thing, but usually as a biker. It's easier for me to stop when I see a yellow from a distance obviously, but I am in the actual intersection for much longer than cars. And busier, more car centric streets usually have larger intersections so this little indicator does a lot for me. Since even going on a green can end up with me being in the intersection at a red at the end, I'll just start coasting even though the light is green if timer is low enough.
Yes! I figured that out pretty quickly when I lived in a city.
Yep, use the countdown too
This is the type of wholesome content I come to TH-cam for
As a physics teacher, that kinematic equation hurts my brain since it's in customary units instead of metric units.
There surely is a metric equivalent where the conversion factor would be 3.6, to go between km/h and m/s.
It is admittedly a quite clean equation as far as imperial-measured equations go
That has nothing to do with being a physics teacher.
i immediately knew where it came from when i saw it, never thought gravitational forces would come into play with determining traffic light times lol
Rob this is awesome. Thanks for taking some time on this subject! My skin crawls seeing people scoot thru reds at high speeds. Almost saw a guy get killed in a crosswalk due to this sort of speeding thru.
-Former class A instructor here.
I've noticed two things I can use as relatively-reliable indicators of yellow light time:
1) Pedestrian crossing indicators, especially when a countdown timer is present
2) The length of the left-turn lane.
For the latter, if I'm in my own straight-thru lane and past the beginning of the left turn lane when the light changes to yellow, I'm good to keep going. But if it turns yellow before I pass the start of the left turn lane, the light's almost certain to be red before I enter the intersection.
Neither is infallible or fool-proof, but they work probably 80% of the time or more.
I like the intersections that have the flashing walk signals and even better with the ones that have the countdown to how many seconds till the yellow. So as your approach the intersection you can see the flashing walk signal and give yourself a little bit of a advantage in calculating the decision zone. But as drivers we get very good at calculating that in your head as long as you're paying attention and not being distracted.
generally... i stop if im short of the turn lane, go if im beyond it
Can we just take a moment to talk about how good this guys videos are? Like the production is really nice and interesting. He deserves more subscribers!
I was just going to say that the frustrating part is that every yellow light has a different time length. Even in the same city or neighborhood. 🤦🏾♂️ There's no way to be able to be prepared unless you travel that way all time.
To be fair the only calculation you should have to make (and if the lights were all timed different but using the equation described it would be fine) is can I stop in time to stop behind the white line. If once you see the yellow it's impossible for you to come safely to a stop behind the line, then you go, if you can then you do. Of course, since many lights are made to make money on the red light cameras or tickets etc... you can't always trust that rule.
@@TenOfZero1 and if the yellow light only lasts 2 seconds then that calculation is wrong. This happens all the time. Sometimes its 3 seconds sometimes 4.5 seconds. Even lights that I take all the time will change length sometimes. Bigger intersections you would assume last longer and some don't. Its always a variation.
Yeah just like a lot of other things too. Like in cities when lanes suddenly force you to turn and theres no way you'd be prepared for it unless you've been there before or using a gps. Texas actually uses square lane markers for this and I'd like to see every other state take notes on the way texas handles their roads and traffic laws
@@AR-xs9uk I think you missed the point of that reply. Pretend the yellow light doesn't exist for a second (like it takes 0sec). The idea is, if the light turns red on you approaching, can you safely stop before the white line? If yes, do stop. If no, just go through (but don't worry it's not actually red it was yellow, and that is why yellows exist anyway). So tldr, the yellow time shouldn't be a factor in your reaction.
@@reububble i think you misunderstood my point as well. It doesn't ever cause me that much stress its just an inconvenience because its always different.
When I was a kid back in the 50's and 60's, we were visiting California (Los Angeles). The traffic signals not only had lights, but little arms that would raise and lower depending on which light was on.
I'm not sure but I think the lights went from green to red.......no yellow. Bare in mind this was 60 plus years ago.
Great video as usual.
Thanks
Bob
Great video Rob! your video is really entertaining and great! made me see the road in a new perspective. :)
11:08 "Nobody makes a right turn at 47 miles per hour." * Tokyo drift theme song plays *
Engineers in the United States should do the exact same thing like in Mexico. The yellow light start to blink letting you know it’s about to go red.
ive seen those in nj, but they're meant for you to yield
I've been through that intersection in Beaverton plenty of times in my many visits to Hillsborough/Beaverton between 2005-2012. Usually we rode around with family/friends so I didn't notice it much, but did notice when we stopped quickly or accelerated heavy through the yellow lights.
When I was driving on my own, getting lost frequently during the pre-cellphone days of google maps, I'd frequently come across yellow lights on backroads on ~30mph roads that seemed to only last 1.5-2 seconds max, with no delay between the changing cross traffic light turning green. I always anticipated a red-light ticket in the mail after our trips down to Oregon (4-5 per year) but never got one.
Surely if you're slowing down, you shorten your breaking distance anyway...I'm lost at the Mats part
It's a heavy topic, for sure. I'm still working it all out, too.
Yeah the longer yellow for turns only makes sense if you only slow down after entering the intersection, which is not how people actually drive.
Whats happening is, you are already close to the light, already slowing down to turn right, and the yello comes on. You have the same problem faster drivers have, which is, you can't slow down enough to stop at the light. But, because you drive a lot slower, it takes you a lot longer to go thru the intersection than those going straight thru it at much higher speeds
@@argh523 If you are already slowing down to turn right and the light turns yellow, you will ALREADY have enough time to stop or turn no matter what without any tweaks to light timing for turns. The distance you need to travel is much shorter when you're turning right AND due to the fact you're slow, the stopping distance is also far less.
I had this happen a couple years ago...was driving through a yellow when someone in the opposite direction left turn lane decided to try to beat the light. He turned left right in front of me and wasn't even CLOSE to making it. I hit him essentially head on going 45-ish. Even with a seatbelt and airbag, I had to get 8 staples in my head and had a crazy concussion. (I kinda felt like I had a cold for about a week...it was really weird.)
Ended up getting a decent insurance settlement that funded my new business, though...so it wasn't a total loss, I guess.
Be careful with yellow lights!!
Mexicos traffic signals flash their green before turning yellow so you can speed up lol
So does Austria.
@@nonionbeezness Since it's only really problematic on high speed road, here in Quebec, Canada we have a sign like 250-500m before the intersection saying "Prepare to stop" with flashing light.
I live about 10 minutes from the Hall - Scholl's Ferry intersection in Beaverton, and it is truly awful.
The issue we had a few years ago was with Beaverton intentionally using shorter yellow light intervals than surrounding cities as a way to increase revenue, and changing the timing without notifying the public. With so many people commuting to and from Portland from Hillsboro, Forest Grove, and Tigard, they knew it would make money.
Beaverton is also notorious for its insane amount of yellow-light cameras, lower than normal speed limits, and high patrol rates, to the point where people that live here actively drive around Beaverton if possible.
Thx road guy for getting me hooked... also holy *beep* that’s my home town!!! I ran that light before :)))) *no seriously why you here tho 🤔
RIP. Hillsboro is a nice area, but the traffic is terrible! How can they use 217 going there and its 2 lanes??? Backed up to I5 most of the time so I just never go up there anymore
Crazy that one mans persistence lead to a change so massive!
The solution is to install yellow flashing lights in a sign way before the intersection that indicates “prepare to stop when light is flashing”
No. It's for the driver to anticipate the lights changing and be prepared.
That's not very practical though.
Some places already do that - I've seen it in Minnesota on highways that have lights.
Some places near me, in Sydney, Australia, have these types of warning. They are used when the lights are obscured - eg beyond the crest of a hill, or just past a rail underpass.
Those are really nice on those limited-access divided rural highways with 50-60 mph speed limits that feel kinda like a freeway with driveways, some side roads, and some intersections with traffic lights.
Well, maybe I'm a little bit late. In Mexico the system we use is also red yellow and green lights but just a few seconds before the green light changes to yellow, it starts to flicker to warn drivers to be aware of the light change
Thanks. I really enjoy watching your videos. For me, it is very interesting to see how the same problem is handled different in Europe and the USA.
Here in Germany there is a law, how long the yellow phase has to be.
3s if the speed limit is 50 km/h
4s if the speed limit is 60 km/h
5s if the speed limit is 70 km/h
@0:57; There actually was a time when there weren't yellow lights, but in place was that both the green and red were on at the same time before the green light went out and it was red.
I was waiting for this video bruh
your video quality is much higher than a channel about traffic would suggest be possible. I laughed like 20 times.
red light camera contracts have been released that show the contract requires shortening the yellow to make the red light cameras more profitable to both the contractor and the city.
Ouch! Unsurprised! Everything is about profit. Do.not.like!
Yep. Bingo! Kickbacks included.
if they want red light revenue, why not time travel back to 1920 and get rid of the yellow light. personally i would have machine gun enforced traffic lights
That's why I appreciate living in a country where the yellow light time is set in law, none of this nonsense.
Ironically, that only makes the intersections LESS SAFE.
I love the lights that flash now before the light changes. As soon as I see them come on I start to slow.
The only car accident I've ever been in was a provisional driver panicking at a yellow and braked into the intersection. I was following the flow of traffic so kept going before I saw them slam on the breaks...
DEM DA BRAKES KIDS
You were following too close bad driver.
@@nut6080 dude ever heard of different kinds of brakes? It doesn't matter how fast or slow you are going if your car don't have good brakes or the car infront of them have better brakes you're going to rear end them. Stop being so quick to judge.
*Crash, not accident
@@2007ghettonissanaltima No, that is not an excuse. If your brakes suck (and I've been there), you compensate for that. NO MATTER WHAT!
Hey Rob, if you have the opportunity to continue I guess a series on traffic lights, could you at some point talk about the Right-on-Red movement?
On the subject of yellow light timing for turns, I immediately wondered how it was that during my mumble-mumble decades of driving experience, I'd never encountered a situation where I'd overrun the white line on red when turning.
Then it become clear - if your plan is to maintain speed until maximum safe braking will get you over the white line at 15 mph, then if the lights change at an unfortunate moment for you, you will inevitably cross the line on red. So it's a bad plan. There's no compelling reason to drive that way. All that's required is to slow down more gradually starting from a greater distance. Then, if the lights chance at any point on your approach to the junction, you'll either be able to stop before the white line, or will cross it before the lights go red.
There are no grounds to for changing the yellow light timing just to cater for needlessly lead-footed drivers.
What a great video. Like so many things in life , “it’s complicated “.
Making traffic engineering fun! I wish Rob was here when I was taking my degree.
"hey honey I got a red light ticket. Can you pay for it?"
"No!"
In some countries, (UAE for example) the light flashes yellow on and off before going solid yellow. Gives you a bit longer on yellow and makes the whole thing easier to gauge. Back in my home country, England, you also get a period before it goes green again of Red+Yellow lit at the same time. This is great because it gives you a couple of seconds to get ready to set off again. Sort of a "ready, set, go". Perfect for over there as most cars (80%+) are stick shift and this gives you a couple of seconds to clutch in and shift before it goes green. I drive a stick shift here in the US, and very much miss the UK style of lights.
Those little bits like “the dump” graphic..! I love that! The edit is just as important to me as the content. And I see you putting in work on both!
I'm a truck driver and I anticipate a long lit green light to change before I get to it. Now there are occasions where it changes at a point where I can not safely stop. Now with my truck often at a weight of about 75,000-80,000lbs I cant, so I if I know I'm gonna run it, I get on my Horn and try to atleast warn, however I always try to slow down in anticipation of it turning yellow.
I appreciate the use of BeamNG Drive for educational purposes!
Oh my gosh! I live near Hall Blvd and Scholls Ferry Road! Thanks for stopping in Oregon Rob, love your videos!
simpsons figured it out. get raid of all green lights and make them red and yellow. this way people move faster
There's another aspect of the formula:
Taking into account there composition of vehicles in that location, and their stopping distances / weights (which affects the incline calculation part).
So they'd need a weighted average of the stopping distance and incline gravity.
They'd also need the vehicle condition weighted average, as vehicles in worse condition generally have worse brakes and hence longer stopping distances too.
I recently got a ticket in NY because I was used to the yellow light length of rural NJ. I think a good issue to bring up is the consistency of yellow light duration.
Traffic lights in my city Medellin start flashing before turning yellow, specially because we have lots of red light cameras so you may get a ticket if the traffic signal turns red while you’re in the intersection.
Dont forget to calculate more time for when you are getting road head and a light changes to yellow
You really put a lot of work into your post production. One of the highest levels I see here. Way more than just sitting in front of a webcam..
I'd just love to see a color-coded line at intersections that tells you when you've passed the "recommended " commit line for a car with mediocre brakes going 5 over, at least on intersections without too much other visual noise.
Maybe just adding a second line like you have for the stopping line? Would be a easy an elegant solution. The only problem with this is that if something happens because someone followed that recommendation the city is getting sued.
@@Arjay404 yeah. My thought would be some inconspicuous blue or purple line that doesn't distract you, but if you know it's there you can use it. I wouldn't want it to be as conspicuous as the lines that direct traffic.
Some of the lights around me are timed to go yellow when the walk indicator ticks down to zero. This is useful in knowing ahead of time if the yellow light is coming. Not all lights are set this way though.
@@TheGerm24 Yeah during the day the ones in my city follow the crosswalk signals but at night they don't.
I have found in most cases the length of the solid white line separating the left turning lanes is a reliable indicator of where the dilemma zone is if traveling at the speed limit. I do not know if this is intentional or coincidence.
I dunno about other states, but I remember South Dakota would often paint solid white lines approaching an intersection that vary in length depending on the expected speed of the road. I realized they were useful to know if you had time to clear a yellow or if you needed to slow down.
You put 2 segments together and you have your own cable show! I love the amount of effort you put into these things! You just made learning about YELLOW LIGHTS interesting! Awesome job Rob!!
I use solid lines as the indicator at an intersection to determine if I should brake or continue. Seems incredibly common in Canada. Inside solid - drive through the yellow. Before the solid, come to a stop.
"People are speeding and we need to account for that or they might get a ticket"
How about no?
Isn’t that the point lol.
Motordom baby!
You can't stop people from speeding no matter what. Not without taking away a LOT of control from the driver, and believe me, you don't want to do that.
So the safest idea is to simply accomodate people who drive about 5-10 mph over the posted limit (which is like, 90-95 percent of drivers on the road) and give them more time to make a safe and informed decision.
@@cameraredeye3115 It's only common because you are accommodating for it. I can assure you the situation is very different over here in western Europe. For starters, the infrastructure is designed in a way that is appropriate for the local speed limit; no airport taxiways in suburbs. If you lower the speed limit, take appropriate measure such as making the lanes narrower, or installing bottlenecks or speed bumps, whichever is appropriate for the desired speed.
On freeways, you can easily place average speed cameras to automate enforcement of the speed limit.
These investments immediately pay off. There won't be fewer collisions per se, but survivability improves as speed decreases, and there will also be less material damage. This means lower insurance premiums for everyone, apart from the obvious advantages of better mileage and less wear on the brakes.
America never fails to baffle me. You MUST park on the right or else. You can ONLY cross at a crosswalk. Passengers MUST exit kerbside. Oh, and of course it's okay to speed a little bit, everyone does it.
Truly mindblowing.
It would be interesting to hear you talk about Baltimore's infamous unfinished Interstate 170, aka "The Highway To Nowhere". Having driven on it myself and seen all the constant bickering about it in the newspapers, it would be cool to get an outsider's perspective on it.
Why is the no counter from 10 to 0 and then it's red.
The same as the pedestrian light
I often look at the ped countdown to determine how much time I have till the green changes.
In some asian countries they do that
Wtf how are you only at 50,000 subs?! I just assumed you would be at like a million til I looked...! Your stuff is great! Thank you!
There are 2 youtube channels i absolutely love but the frequency of videos is just not enough to satisfy me. This is one of them. (The other is Casual Navigation). When i win the lottery I am dumping thousands of dollars on this channel for more videos. :)
On highway 89 in utah they added yellow flashing light's an 1/8 mile before the stop light, the flashing yellow lights came on before the yellow on the traffic signal.
This road has a 50 mph speed limit and the dilemma zone was huge before they installed the extra lights.
These uploads are so good. I've never knew I could care about what happens behind the scenes in traffic. Goes to show that what we typically see is only a fraction of what's going on. This applies to just about everything.
In the case where the truck couldn’t stop but the car could stop, the truck was too close to the car. That’s not a yellow light problem, it’s a tailgating problem.
In Australia, or at least my state in Australia, traffic lights will have a "buffer time" in which all lights will be red at the same time for a couple of seconds to allow for cars trying to beat the yellow light. You will still be booked for going through a red light but at least you don't get in an accident
This is also why you should always check for traffic before entering the intersection on a fresh green!
I'd imagine before long traffic engines will be using machine learning to decide how long to make the yellow at each intersection.
7:55, that's CRAZY that they use 1 second. In aviation, they use 2 seconds, and if you watch how long it takes for the average car to move at a green, it's about 2 seconds per car. Count next time you're queued at a light. It's almost perfect.
Another issue is the initial reaction of a driver to hit the breaks then relise they wont stop in time (or vehical behind them etc) so they have to continue but at a slower pace
You're one of the very few TH-camers I have notifications on for. Great video, once again!
Great to see Pickup truck Drivers in the States just drive like the equivalent here in Australia to our Ute drivers.
They are all cut from the same cloth by the looks of it.
In Austria, the green light starts blinking before it turns yellow giving the drivers a warning and therefore closing the dilemma zone. Some lights in China have timers attached to the green light so you can time yourself, and decide if you can make it.
Rob called the dilemma zone and "invisible line" but couldn't they just paint them on the road? One for cars, one for trucks. If you see the light turn yellow and have not yet passed the line, you stop. Even if you were to make it, they could make passing the limit line on a yellow if you passed the dilemma line while it was yellow an infraction. This would even be compatible with red light cameras.
Back in the early sixties when I lived in Peoria Illinois stop lights as I remember, only had red and green, no yellow !
13:35 the truck kept an insufficient distance towards the car in the first place
Beamng is an excellent game. I appreciate the dramatic reenactments.
Not a perfect solution since times are different depending on the light, but I wonder if it would be plausible for engineers to determine the appropriate time on the yellow light and then use that information to have road crews paint a line across the road to denote who should stop and who has time to continue. If you're behind the line when the light turns yellow, you know you don't have time and must stop. If you're inside the line, you have time to continue through the yellow light.
They are even in states where red light cameras are illegal. In the latter they just have the cops play road pirate to get the same revenue.
0:22 I love how he included BeamNG :D
“In 1980 the federal Highway administration found that...” We are not in 1980 anymore. Population size and automobile technology improvements would greatly change that study. Obsolete!
One of the problems with the formula is that it has no input for condition of the road such as when it is raining or snowing. A 4 second yellow might be barely enough time to stop when road is dry but is way too short when road is wet.
Very well done as always, thanks Rob!