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.
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.
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.
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.
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.
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
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.
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.
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.
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.
Great video rob. My government puts speed cameras on some of these intersections too, so it's either I brake and get hit from behind and possibly killed, or I speed through the yellow and get a speeding ticket.
@@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.
Probably the only person in the world who can make learning about traffic lights, off ramps, intersections, tunnels, bridges, etc. actually entertaining to watch.
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!!
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
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
In China, I remember the green lights blink for 5 seconds before changing to yellow. I found it's more clear of when the lights turn red. However, the more clear of the timing and stoping distance, the higher chance of violating yellow light anyway.
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.
Here in Vancouver we have different laws. When going straight, if any part of your front bumper crosses the stop line when the light is still yellow, or was just yellow a second ago and it just turned red, it's ok to run the light. When turning left you can't turn during the yellow because of everyone running the light so it's ok to turn left during the first bit of the red light, and if you are the second or third car in the turning lane and you all stick together like a little train then you can all go through the red. When turning right you never need to stop for any reason, just keep creeping forward through the crosswalk and nudge any pedestrians or baby strollers out of your way gently.
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
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
That solid white line at every intersection is the range to consider when stopping at that speed. Either speed up towards the light or slow down. The hard problem comes when gas stations or other rest stops are placed too close- or even too far causing another type of back-up problem trying to allow someone in.
I live in New York City and it has a 3 second yellow light standard in every intersection regardless of speed limit in the road. The awkwardness I feel when I stop “too early” at a yellow light whenever I am outside the city limits. This inconsistency from county to county makes it worse.
There really needs to be a national minimum set. Fixed ratio to the road speed limit +.5 seconds for reaction time, if they want a red light camera it's required to have a ~1 second grey zone so we're not punishing people for minor lapses in judgement or avoiding being hit. Fuck, maybe even nationalize production and the software. Don't really need 10 tiers of corporate bullshit for a plate reader hooked to a camera that sends out fines.
@@Joesolo13Red light cameras are rather problematic in that you're not required to stop for a yellow if you can't do so safely and that can lead to running a red light in cases where the yellow isn't yellow long enough.
I've known Road Guy Rob for a while now, and I'm proud to see how much traction his videos are getting. He deserves it. I'm a proud patreon supporter as well, even if it's a small amount.
I love how at the 5:00 minute mark, you're talking about how a longer yellow light makes an intersection safer while simultaneously showing a van still running the light.
In the UK, the yellow light is a fixed 3 seconds for every junction, regardless of speed limit or inclines. There's no guessing about which formula the engineer used, so the mental indecision calculation is a lot easier. But it does mean that it's up to drivers to realise that if they're approaching an intersection on a high speed road or down a hill, they need to drop their speed a little in case it changes.
In the UK, we just use a flat 3 seconds for all amber times. We do have equations / data tables for the full intergreen though which affects the all-red time.
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).
In Switzerland yellow lights are only 3 seconds and it is horrible. Especially since there are a lot of Blitzers for red lights here. I love driving in the U.S with 4-5 second yellow light, it really gives you time to make a decision. In Switzerland you‘d better just mash the brakes when you see a yellow light, because if a Blitzer gets you, you usually loose your drivers license for a couple of months. As I said: it‘s just horrible here😭
One of the best things about Tesla autopilot is that it takes the guesswork for red lights out of the equation. It instantly figures out if it needs to stop or go and it's always really accurate.
I commute through Chicago to my University almost every other day and we really have bad yellow lights. From what I could find on the internet, the duration is just 3 seconds long. This causes drivers to suddenly slam on their brakes or to actually run reds because they can't or don't want to decelerate that quickly. Thanks to this, there is an intersection by University that CONSTANTLY is able to flash people for red light tickets. I found watching the crosswalk count down to be the best bet here. When I see it at 3...2 I start braking and am usually able to stop at a reasonable rate thanks to this.
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. :)
When I get trapped in that position and just go through, I always flinch and cringe my face because I’m always worried a cop will be right there at the intersection
Love this video, the work that Rob puts into these is incredible. Hope he does one about the way lights are timed with other intersections to keep traffic flowing because that seems like a huge mess.
There was quite a fuss in Florida some years ago when it was determined that some jurisdictions had turned their yellow light timing down far enough to guarantee people would trip there red-light cameras and run up Revenue. A reporter for WTSP in Tampa did a bunch of investigative work on it, and a bunch of those timings got readjusted
This is one of the best channels out there. Thank you for the great content, Rob! I think your potential audience is much larger than your current audience considering the number of people who drive on the roads. Keep up the positive attitude and the fans will roll in :) I'll be telling my friends about Road Guy Rob!
There was actually a push here in Maryland a few years ago to make it a law about how long a yellow light should be. It actually passed, but only affects intersections with a red light camera. In Maryland, if an intersection has a red light camera, the yellow light must be a minimum of 3.5 seconds long.
As a new driver I’m always confused when I’m supposed to stop or not, because they never really talked about it in driving school. I’ve also had the same idea about a line on the road but if you’re passed you keep going and if you’re in front you stop
We have different yellow times depending on the speed limit of the streets. Its a fixed value for every different speed limit that you learn in the drivers school.
I remember encountering some traffic lights that would turn yellow for only a few hundred milliseconds once in a while. Then one time there was one that would turn green for only a few seconds then stay red for 4 minutes. Traffic was backed up for miles.
In Minnesota, where snow and ice is common, safe stopping distances change radically when the roads get bad. When conditions are very bad, good drivers expect cars to drift through the first few seconds of a red signal, rather than spin out in the middle of the intersection.
Here in British Columbia (in Canada) there are are flashing yellow lights placed before the intersection at the point where if you can see them when they start flashing you have enough time to decelerate and stop for the red light. Basically at the start of the "indecision zone". Especially on the Highway, this is very handy. If you see the light at the intersection turn yellow, but you've already passed that sign, you don't have to speed up to make it through.
Here in Orlando our dashed lane lines turn solid well before the intersection. I use them as my "point of no return" reference. Usually if I'm within the solid lines I know I can cross before the light turns red.
I don't know if its everywhere but in China traffic lights show a countdown for red, green, and yellow. It's kind of like some of the pedestrian lights in the US.
Federal DOT's Manual of Uniform Traffic Control Devices states that ALL of the nation's Yellow Lights must be AT LEAST 1 second per 10MPH, if the speed limit is 25MPH, the yellow light must be at least 2.5 seconds. Here's the funny thing, many Red Light Camera intersections are set to have a shorter yellow light to drive up fine revenue. Most of these are managed by Private Corporations that outsource these fine services to the township, for a slice of the revenue pie--so there is a profit incentive to shorten the yellow light--even though this adds to the amount of rear-end accidents when people jam on their brakes. And, when I spoke to a NJ Highway person, ALL of the country's township traffic departments can remotely set the following: 1) The timing of the lights; 2) Randomly set the yellow lights to cycle one time and then another time and then back to the original time; 3) They can set the lights to be shorter every 5th or 10th traffic cycle; 4) They can watch your vehicle approach the intersection and immediately change the light controls. Modern traffic lights can be changed at will, so the only way to catch this happening is to set up a camera and film the intersection.
I find it extremely appropriate that Hall Blvd in Beaverton is the road singled out here. The lights on that thing are real-world diabolical. I'm a limo driver, and I'll never forget the time on Hall when I dynamited the brakes as soon as the light went yellow, barely got the car stopped, and the light was red well before. What's crazy is, that was from 5mph UNDER the limit, and UPHILL. The passengers in back happened to be passing a champagne glass from one person to another (with apple cider in it for a kids' birthday btw; no Goldman Sachs bankers onboard) at that moment, and it went flying and broke. Had to pay for that one myself; it wasn't their fault, and Portland Bureau of Transportation are for damn sure not going to cover it.
From Portland, thank you for featuring locations from my hometown here! I remember that gentlemen that was contesting the yellow lights lol really the civil engineer fine was the silliest thing. Some people have some inflated egos in those fields of engineering!
The times I hate yellow lights like red lights is when people decide to break/stop right at the white line without even giving a heads up like pumping the breaks so it makes me believe they are crossing the yellow light when indeed they dont.
I studied up on this years ago when I hgot a ticket due to a ridiculously short yellow. One thing omitted here--traffic engineers are supposed to keep the cross-traffic light red for a couple of seconds after the yellow turns to red--in case someone in the decision zone makes the wrong decision. My observation years ago was that the biggest problem occers when you're not quite certain if it's stop or go, and you waver and perhaps go from gas to brake to gas again to brake again. My approach since has been to base it on the lines in the road. The dashed lines turn solid at some distance before the light--if I'm by the dashes, I'm stopping, if by the solid line, I'm going. Works for me.
I have not finished watching the video yet, but I am loving it! Tons of major intersections on very busy highways bisected by slower off streets in MN have flashing lights. If you are going 55 when the lights flash you should expect to stop. It is hugely helpful when you are cruising at 55+! You have plenty of time to safely stop. Not a simple problem.
I lived in Florida for several months after Katrina and I figured out the solid queue lines are just long enough to slow down to a stop from the beginning of the lines right when the light turns yellow and come to a complete hslt at the stop line right when the light turns red, when travelling at or slightly above the speed limit
I think a good way to prevvent people running yelllow lights is the use of countdown for traffic lights. This gives the driver a better way to figure out the change time of lights while stopping and while the countdown is at a red light, drivers could prepare to drive a bit earlier as well. I have seen this timer system at the traffic lights of Mumbai, India and honestly felt that red light running is considerably less out there and drivers feel less worried about running a red light.
So, according to your calculations, no trucks should be on these roads. One second for reaction time, then trucks with air brake take another second before they activate. Wet roads also give us problems. Maybe in rain and snow, add a few seconds to the yellow. Philly has shortened the yellow on red light cameras, to get more tickets. Around the state, when you see skid marks before the light, it’s a short yellow. Some lights have been green as I entered the intersection and red before I got to the other side!
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 remember reading somewhere that yellow lights have to be at least 4 seconds long by law, but I'm not sure if it's the whole continent or just Canada. In my experience every yellow light I encountered and timed in Ontario has been precisely 4 seconds,, except a few lights in rural areas with higher speed limits that were more than 4 seconds. My rule of thumb, start a 4 second countdown when I see the light turn yellow, if I can't make it without applying more throttle, stop, otherwise just hold speed. You what would be most beneficial? A countdown timer. Takes the guesswork out of the equation. Using it for red to green could also help eliminate distracted drivers not seeing the light turn green.
That calculation step is no joke... I see yellow, and I figure I got about 2 tenths of a second to determine my exact stopping distance and whether that's gonna exceed the entrance to the intersection, then decide whether I'm grabbing a gear or locking it up... you can't stop 80,000 lbs on a dime, much less if the goods in the box are prone to shifting. Which is honestly even scarier when you got a 4 wheeler in front of you, making that call for you without any of the context that you have to work with...
In South Africa, if a robot turns red, the other robot does not turn green instantly, there is a 2 second pause where all robots will be red before the other robot can turn green. That way if a robot turns yellow, and you approaching the robot and you cannot safely stop, you can pass even when it turns red before the other robot turns green. But the speedlimit is such that a scenario explained above happens once in a long time and chances are that if you see a yellow robot and you cannot safely stop, chances are that you were going above the speedlimit. Another tip is when approaching a robot, always approach at a speed you would be able to safely stop should the robot suddenly turn yellow.
In the city I live in we have these pre light warning signs that start flashing before the light changes, basically if you’re going the speed limit and see these signs start flashing the light will be red when you get to the stop line. It’s usually in zones that are 70km (45MPH) or higher with traffic lights, and steep hills with lights at the bottom, or blind curves
"The heavier truck cannot stop" That's not a fault of the traffic light or the car that stopped in front of the truck. That's the fault of the truck driver for not keeping a safe distance to the vehicle in front, assuming the vehicle in question didn't cut in front of the truck prior to stopping. In fact, this whole "dilemma" is pretty easy to fix... Whatever your safe distance to the vehicle in front is should also apply to the traffic light in front of you. If the light turns yellow as the vehicle in front of you passes the light, then you have enough room to stop. If you don't then you are technically tailgating.
RoadGuyRob hitting all my intersections. Victory Blvd near my mom's work, Sierra / Via Princessa in Santa Clarita near my brother's house, and Woodley / Roscoe my dreaded side road when traffic is awful on the 405. It would be awesome for you to document how cities determine whether to put a dedicated arrow for turns and when they choose to increase the grace between lights turning Red then the opposing light turning green.
I'm glad I watched to the end before commenting. I almost told the story of a guy from my area named Mats Järlström who got fined by the state for doing yellow light math...
OMG that part of hwy 79!!! Recognized that instantly! Great scenery drive in the morning, going downhill from Beaumont..great memories...never noticed the dump though haha... Great video as usual! You deserved so, so much more views and subscribers!
You know what’s worse than the dilemma zone, snd the groups 1 and 2??? The freaking passenger or co pilot next to you that decides to talk trash and demanding to either GO or STOP!!!!!
My dad taught me that if you have enough time to hesitate on a yellow, just stop. Of course its a different story with a cement truck barreling behind you, but part of driving is being aware of everything. Great video! Seriously a good drivers ed class right here
