The Phantom Traffic Jam - an explanation

Andrew Marr explains the phantom traffic jam from a cherry picker and then on a computer graphic.

[@commiellama]

So here I am, watching traffic on KZbin

[@KennethSchh]

+commieman To some extent even watching people watching traffic.

[@tiredsentinel1724]

😂😂😂😂😂 Awesome comment!!!👍🏻

[@stoddcrew]

This still wasn't explained as well as it could have been. The reason the wave spreads is because the cars at the front of the jam accelerate more slowly then the cars at the back of the jam can decelerate by hitting their brakes, this is partially caused by slower reaction times when accelerating compared to decelerating and partially caused by the fact that all vehicles accelerate less rapidly then they decelerate in the mechanical sense. The best thing is for people coming up to a jam is to maintain a constant speed that allows them to arrive at the jam just as the last car in it dissipates. This allows the car arriving at what used to be a jam to never stop and create their own stopped traffic wave behind them. For the people at the front of the jam, they should pay attention and accelerate as quickly as is safe but only to a speed that allows them to not hit a jam ahead of them before it also dissipates. Adding to that when traffic is moving it coalesces more rapidly, impatient people who are accelerating to an unnecessary speed to then slamming on the brakes when they hit the next jam create road conditions which make it more difficult for the surrounding traffic to coalesce fluidly. As is generally the case in multi-lane highways the cars who are hitting their brakes and starting traffic waves behind them are the cars who didn't keep an appropriate distance in front of their car to let traffic merge fluidly. The last thing to understand is that a lane on the roadway can only be saturated by so many cars before that lane naturally slows down due to people slowing down to create a comfortable distance of safety from the car in front of them. The best way to deal with this is to move out of the lane where their is a merging point ahead, doing this decreases the number of vehicles in that lane keeping the saturation even with the other lanes. Rarely is it the case that traffic is completely stopped due too to many cars getting on the road at once as is the case after major sporting events and is generally caused by the imperfections of human nature.

[@JoeWisniewski]

This a absolutely correct. I couldn't say it better. Most jams are caused by bad users. No matter how fast you accelerate out of the jam, the wave will continue to propagate until there are less cars entering it. Most of all leave room and don't tail gate.

[@Nikkerz232]

As a Truck driver in the USA, i approve this message.

[@Weaseltube]

This is very well stated however it's no good to leave such a gap that another car might just fill it from another lane, or drivers behind might get annoyed and become erratic. What drivers need to do to decelerate more gradually and accelerate more promptly is to look as far ahead as possible and react to what's about to happen, instead of what's immediately happening. Of course following to close negates the advantage of looking ahead which is where you're absolutely right. But anticipation is they key, not the gap.

[@1malditoPerro]

Good luck trying to teach that to people. It's surprising many of them have a driver's license .

[@alawkabi1649]

beautiful

[@steecheeful]

Ok, it has reached that point. Time to stop watching traffic videos (holy shit there are so many) and get my ass to bed.

[@DasBeatz]

Goodnight. May your dreams be just as mundane.

[@jarvusff7726]

Steven Butler three years later and you predicted my thoughts..

[@Engineer9736]

I’m watching this in bed 😋

[@CStarkGolf]

How was your sleep?

[@steecheeful]

@@CStarkGolf i haven’t slept in 8 years

[@fredsilvers1427]

Maintaining a considerable distance, to the point that the stopped traffic ahead of you starts moving before you reach them eliminates stopwaves. I realize people cut in front of you but that also relieves traffic bound in that lane. Slow and steady makes everyone behind you not have to stop.

[@nikostalk5730]

this called a "buffer" driver, he helps the whole jam to "start a movement", just by rolling at slow and constant speed, instead of "start-stop" error. This is how you and your friend on a second lane - could EASILY remove a phantom traffic jam

[@CaptainJacksIsland]

No matter how much cushion you give the car in front of you, there will always be someone to cut it in half.

[@LabTech41]

There's a number of factors that work in concert to produce traffic jams, and they're all essentially emergent patterns that arise from a few basic bad habits that most drivers have. You have the dichotomy between the ones who drive too slow, and the ones who drive too fast, you have the system being clogged by things like rush hour (which honestly shouldn't exist anymore because the 9 to 5 work schedule should be phased out in lieu of more staggered schedules that allow it to be spread out over a longer period, thus reducing load on the roadway), and then you have basic lack of accommodation and courtesy for fellow drivers. A lot of the slowdown happens because virtually nobody pays attention to the proper amount of distance you should have between cars, and virtually nobody makes any kind of effort to help people get from one lane to another; to many people are either oblivious or are out for themselves. If you leave about 4-6 car lengths of space between you and the vehicle in front of you, you can vaporize traffic jams because nobody's slowing to a stop to get a lane over. Next time you're in a traffic jam, try it; instead of being a foot from the next car's bumper, leave a good couple car lengths, and watch in amazement as car after car uses the gap you've created to get by, and watch as it frees up all the other cars to proceed forward. If even one out of 50 drivers did that, we wouldn't have traffic jams.

[@penalozaur]

+LabTech What's wrong with you, bruh? Demanding that people use their damn heads and not looking into the stupid ass phones?

[@nateguthrie6367]

Amen!

[@handlesrtwitterdontbelivethem]

too much yap

[@LabTech41]

@@handlesrtwitterdontbelivethem TL;DR you strike me as an idiot, and idiots cause traffic jams. Sufficiently short enough?

[@handlesrtwitterdontbelivethem]

@@LabTech41 at this point everybody is gonna get a bugatti that would solve the phantom traffic problem

[@Shimmy02]

Finally someone explained the phenomenon i've been noticing and trying to explain to people for years!!

[@Wardropulous]

This is kind of intuitive. Whenever I'm in traffic or stopped at road works, I always try and accelerate at the exact same time as the person in front. In theory, if we all started moving at the time the first car started moving, everyone would get up to speed much quicker.

[@OleOlson]

Note that the solution to this surprisingly isn't 'more tarmac'. The US has tried over and over to expand roads with more lanes, and the only thing that happens in 5 years later there are more cars on the road and everyone is right back where they started. The solution is public transport and companies allowing flexible start/stop work hours.

[@AccountInactive]

Too many people have to go too many places for public transport to do anything effective in American major cities. This isn't Japan.

[@mjhammer8121]

Drivers can do quite a bit to prevent traffic jams in the first place by using cruise control and staying as far to the right (in the U.S.) as possible.

[@BenMcDevitt]

I waited 45 minutes to see this accident, your dang right im slowing down to look lol...

[@46Bax]

Hahahahah samee

[@bunchabaloney402]

These Phantom Traffic Jams are what I call 'The Slinky Effect'.

[@flowertrue]

Just looking at that thing makes my palms tingle. And yet, inexplicably, given an opportunity, I would totally go up in it to look down at the traffic

[@johnwan6300]

The two lanes merging on left hand side (1.10 frame) are wrongly designed adding to the problem. Vehicles merging at two entry points instead of one; this in itself created two bottlenecks therefore slowing flow even more. A lot of road congestion is created by road engineers.

[@NSUScooter]

Great observation

[@Engineer9736]

There we have the keyboard hero

[@josharmour]

We need self driving cars as soon as we can get them..

[@805NAVE]

Josh Armour no way, fuck that

[@omnipresentvideo7686]

No, we need smarter people, not smarter cars.

[@willburr1786]

Socialism. Loss of jobs would be staggering.

[@dutchy777]

agree to better driving NOT driverless cars, 2 crash into each other, who is at fault?

[@suryahr307]

@@dutchy777 no one because there can't be 2 automated vehicles crash into each other

[@fish4fun354]

I always look way ahead just kind of idle into slowed up traffic to prevent a whole lot of people locking up their brakes behind me, but always some asshole who figures there's lots of space in front of me so I get people in front of me on waiting their damn turn. This is how rear ends happen.

[@titoosen3494]

I find that computer-generated model interesting. Now what if the cars ahead of the line accelerated faster than the cars behind the line decelerated? Would that still cause a jam or would the jam vanish altogether?

[@SaltE333]

+Fluffkin Alexander it wouldnt vanish

[@Blabus5]

Am I the only one who slows down before last second so instead of stopping behind the previous car i still slowly roll and then the previous one starts again?

[@Robbedem]

White van crosses markings at 1:11 :o It's people like this that cause traffic jams!

[@NSUScooter]

No, that lane crossing was a result of that slow moving semi in front of it. Had traffic been moving faster, there would be no need to rush like the van did. A better cause of traffic jams is the lack of urgency to have well SKILLED drivers. We have well TRAINED drivers who basically stick to one rule which is “don’t speed.” Nothing else really matters to most drivers including using turn signals.

[@ericwsmith7722]

TRAFFIC JAMS ARE CAUSE BY ONE REASON, they are caused by people trying to go faster then the flow of traffic at peek driving times, and worst then that, those are 90% of the drivers out there, And all there antics behind the wheel to get one or two car lengths ahead of the "pack", tailgating, changing lanes every 5 minutes, not letting people merge in, stopping in the driving lane because they waited till the last possible second to exit, blocking the box, etc etc etc Enjoy the ride dumb assess you deserve it !

[@akzebraminer]

Reporter: Do you know how phantom traffic jams are made? Guy: I sure do. Here, I’ll show you. Let me get my crane....

[@jameshiggs9585]

what about when traffic is bad up to the point of an off ramp, but as soon as you pass the off ramp it is clear as a bell? ahh I know what you are thinking... half of the cars got off on the offramp right? no! the particular section I am thinking of has only a couple cars here and there getting off, and the freeway that continues actually loses a lane, yet traffic speeds up 4 or 5 times the speed it was going!!!

[@format6154]

People slowing down to change lanes to get into/out of the offramp lane would be my guess. It would go a lot faster if people changed lanes well ahead of the offramp.

[@UncoolRandy]

I demand an explanation as to why people who cause these aren't arrested. It's poor driving and it affects us all, much more than speeding.

[@yorkshire_tea_innit8097]

So the cause is a human instinct to tend to brake slightly more than is needed, and the excess gets accumulated on and on if there is no buffer zones.. Pretty cool and all the more reason to hate tailgaters.

[@seinfan9]

+Ryukey Tailgaters are one reason. You still have people that enter and exit the ramp, which necessitates those already on the highway to be more cautious and to slow down. The jam is the resultant effect of the inevitable delays in our reaction time that propagates and accumulates as you go down the pipeline of traffic. If our brains could process information and execute actions instantaneously and we were all somehow synchronized, this wouldn't happen.

[@ericwsmith7722]

NO..... that's not the problem YOU are the problem, you are one of those people who speed up so that a car can not merge onto the highway in front of you. Bringing the whole ramp to a stop, now they cant merge at speed, in turn slowing down the whole right lane, and like a cancer, consumes the whole highway. but guess what, they are in FACT coming onto the highway no matter how many stupid drivers try and stop them.

[@seinfan9]

eric wsmith What the hell are you going on about? This isn't like some marching band routine. People's actions on the road are random independent events that propagate delayed reaction times. It's inevitable, you jackass.

[@ericwsmith7722]

why you think that is because you are looking for the lane that you think is going to get you some place faster, you are not looking at all the traffic. there acts are NOT random, they are all (90%) doing the same thing, accelerating up to stopped traffic, tailgating , changing lanes, etc etc while they are all individual acts, they are mostly acting the same way. herd mentality. Ask yourself this, what possible reason would anyone have to accelerate to 30 or 40 miles a hour in stop and go traffic ? so you can make sure no car get between you and the stopped car ahead of you is the answer,,,, and that is just as stupid as it sounds . And what's even funnier is that car that had the gall to get ahead of you,,,,,, will not be there loge, they will be trying another lane very soon. All that stress and BS, to keep some one from possible getting 100 feet in front of you, which at 30 mph is a little more then a second.

[@seinfan9]

eric wsmith Pay attention, tool. All it takes is for one car to slow down the flow of traffic. That's it. You can rant about people being assholes on the road, but this isn't the sole reason why this happens. Once again, dumbass, one car causes a propagated and accumulated delay and it can be for any reason. Like avoiding an obstacle in the lane, or even simply slowing down after realizing they are too far above the speed limit. That is all it takes. Your diatribe is of no consequence to the reality that all this is unavoidable.

[@rogeriopenna9014]

what do they mean "with no clear cause or reason"? The cause is clear: human reactions are too slow. If any human could start accelerating the INSTANT the car ahead starts accelerating again, phantom traffic jams would not exist. They happen because humans need a few microseconds to react between the car ahead accelerating again and you accelerating again. Those microsecond ACCUMULATE backwards.

[@thealliedpowers]

You do know you're supposed to let the car in front of you go so you have a space cushion in case, you know, they fucking crash.

[@digitalbroadcaster]

From traffic jams come crashes. Especially from the time that platform was lifted high into the air. I bet that road never had a traffic jam in its life until that day!

[@1973Washu]

Hopefully self driving cars will lessen this phenomenon.

[@OnionChoppingNinja]

self driving cars are a load of horseshit. The only way to reduce traffic jams is to reduce traffic. Get folks out of their cars and onto buses, trains, trams or bicycles.

[@traviswaldorf]

Black mirror episode idea: the cause of the butterfly effect of phantom traffic jams can be calculated by the technology in phones/cars of the future and a man who innocuously lightly taps on the brakes on the highway causes some catastrophic damage down the highway behind him, resulting in someone important dying, or some major damage done to a building. He is blamed and tried for this, and during the trial process, his butterfly effect compounds, and realtime analytics of the program/company that deduces these kinds of crimes shows the continued propagation of it until he is sentenced to death for killing 100 people in some random place. Other examples of butterfly effects being monitored too can be shown in the episode as well as his legal team tries to race and deduce what caused him to tap on his breaks lightly. Could have something interesting to say about ethics, causality, and how society places blame on individuals. Who really is to blame for X?

[@GuitarSlinger2112]

LOL "one of the biggest traffic jams in the UK motorway network" Those people are still moving at 20 mph... I feel really bad for them.

[@XdjdaleyX]

I didnt turn on the sound on because it was Andrew Baaaaa but its something to do with driving too close to the car in front then breaking harshly right?

[@mattyfizzle]

Um why did this need to be explained. Isn't it already apparent?

[@TimpBizkit]

Or traffic jams could be caused by a man trying to jump off a motorway bridge - such was the one one the way back from Coventry last year.

[@ericalexander3246]

Tim Lewis Sorry about that, mate. I recovered from my problems and won't do that again.

[@livedeliciously]

Watching this will do nothing to help my road rage.

[@neil340]

Holy cow that crane is high up.

[@gearoidmoore7472]

You can see it wobble too when the presenters are talking, Andrew grabs the railing pretty quickly. Must be scary

[@iamjustjudy]

Also a great way to rear end the car in front of you if you miscalculate how fast they speed up.

[@Engineer9736]

Time to hand in your drivers license then if you have difficulties with not rearending people?

[@DashCamNetwork]

well it all makes sense now

[@blueShinyApple]

Anyone know the name of the song starting at 1:30 ?

[@MrAkilio]

a sim city soundtrack?

[@46Bax]

just shazam it

[@justjayok1]

Way to create a traffic jam with your crane. Everyone slowing down to see what you're doing!

[@liamhogan6079]

I wonder if they put in stop lights that detected this pattern and cleared jams like this.

[@Engineer9736]

Obviously they didn’t as they are not there.

[@123syflox123]

Can I get an American translator on this?

[@AnUndeadMonkey]

Fuckin' cars, man.

[@miked3569]

What could you not understand about this? Pretty fuckin' dense.

[@Pcr06]

Just a whole lotta automobiles dude!!!!

[@DeVstatrOmga]

People suck at driving.

[@ling4460]

How hard is it to understand lol

[@officergregorystevens5765]

Love UK shows. So much better in general than our stuff, in America here. that is the US of A. Not to mention so many fundamental concepts of our shows we got from your shows, heh.. little credited.

[@Dpozo12]

Getting angry at watching traffic that I'm not apart of that I'm voluntarily choosing to watch. I must be a masochist.

[@officergregorystevens5765]

That looks like an unusually tall lift, or whatever you call those things.. , oh boom lifts.

[@krazykangaroo]

That's just a crazy idea, guy.

[@nhanha7433]

Two commercials move in two lane too close the commercial in the front fail to detect the commercial truck on other lane from behind. The behind commercial truck from behind but fail to keep apart because untrained. The camera spot but no enforcing. This lead crowded and jam and slam into each other later.

[@cornucopiahouse4204]

Now what is the solution?

[@Speedkam]

Maintain distance, dont speed and slow down the traffic that approaches fantom queue

[@architektradim]

Trains

[@cutah321]

And thats not all either. Most of the time the number of cars stuck in traffic follow the Fibonacci sequence.

[@patmcbride9853]

No one really tries to recover speed when they can.

[@funnypranker34]

Pat McBride I try to but the family aka "passengers" don't like it

[@patmcbride9853]

Peter Kapica Passengers are the worst!

[@funnypranker34]

Pat McBride I know. They want me to drive like a Cadillac

[@AZYKULAN]

Who can suggest a software to model a traffic jam?)

[@AmperaService]

So it only takes one knobhead to start a traffic jam!

[@janetgray9685]

I this case people were stopping to see the lift

[@theFez013]

That’s exactly what I always suspected but it seemed too stupid to believe that was actually the only thing causing it 🤦🏻‍♂️

[@patrickbertlein4626]

People have to hit the brakes too hard at least half of the time because of people changing lanes. When you leave one lane to enter the one that is flowing better at the moment, you are only creating more traffic in that lane. Know your lane, stay in it, and stop trying to get ahead of everyone. It really is that simple, and no I am not perfect no one is, but for the most part I know changing lanes too often is what causes many accidents and traffic jams. It should be illegal to switch lanes more than 3 times within a mile, unless it is to get to an exit, and even than if you are waiting unless the last minute and making all the other cars let you in, again you are causing traffic and risking an accident. All goes back to the same thing. Lane changing needs to be what police are focusing on, and not speeding which is more often than not ridiculous because from DC to Seattle, you go with the flow of traffic which is almost always 5 mph more.

[@ElectricityTaster]

If you dont keep your distance then you create a traffic jam.

[@vicksoma]

How to resolve a traffic jam: Once you're at a standstill and you get moving again, you (safely) race ahead to try to get back to where you would have been had there been no traffic jam. If everyone does that, they get back to full speed.

[@stevemt3422]

People who drive slow on left lane and making cars at back to pile up are one of the main causes of traffic jam

[@domkennedy5203]

These guys must not be afraid of heights 😅

[@spooknok]

You're telling me I have the power to ruin everyones day by just breaking a little too hard? That's awesome

[@samreagan6292]

This is the worst spot to explain the phantom traffic jam because this is 4 lanes going down to 3 lanes or something like this.

[@kamiakin5]

@WolfgangHalldorson i am pretty sure you are thinking of mr and mrs smith with brad pitt where he is telling his dinner guest about his "job"

[@1776Rosco]

They're driving on the wrong side of the road, that's the problem!

[@byronboydstun2222]

Well for starters, everyone is driving on the wrong side of the road here!

[@Guywithcrazyideas]

I died today.

[@46Bax]

what about 7 years later ?

[@ottotater2787]

Yes there is a clear cause and reason and science knows. He IS TALKING about ot. It's traffic going the same speed as traffic in AA different lane. always go faster than traffic and the driving lane and only for the duration of passing and then move back to the driving lane. Never travel the same speed as traffic next to you. Never travel forward until you already have a clear open path not a planned path but an already open path do not plan for that guy to get out of your way but wait until he's already out of your way and always for instance in the United States travel faster than traffic to your right and slower than traffic to your left however left hand drive countries are going to be a different dynamic because the off ramps are still on the same side of the roads

[@thevillager8102]

I like to see truck in traffic jam

[@darky4555]

It's bad road design that causes the phantom traffic to begin with, blame the design not the drivers.

[@datafreak667]

finally i know how to make 400 people late to work

[@oscarmelchorgalan3092]

The phantom of phantom traffic jam has been unmasking. Looking for wavedriving in youtubr.

[@fariasttiago]

0.25 and its hilarious

[@QQTrick1QQ]

When you are self centered like 99 percent of people and do not leave a space for a auto to slide in and keep moving some self centered driver has to stop and let them in, hence stop and go traffic..If you leave enough space you don't have to stop, and traffic flows if only a percentage of people did this traffic could breathe

[@ikmarchini]

Explanton? Humans, in all their vagaries. Computer controlled cars on interstates solves the problem. Start with something doable, Elon.

[@Icharus88]

Thats why i ride a kawasaki!

[@MAT999]

you can correct the proplem if you walk 10 kmh non stop hhhhh

[@abeff]

drone before it was cool

[@Savaniel]

@vicksoma Haha or you get in an accident and cause an even bigger traffic jam!

[@turo0325]

i came from 9 gag

[@jorgeriveramx]

me too

[@woah.montana]

Ppl drive too slow

[@melkiy582]

Компьютерная симуляция в данном видео полный шлак

[@burns83]

Theres always gonna be people stopping. By law Speed Limits vary. Also certain lanes can handle higher speeds than others. The real reason for traffic is not breaking, thats stupid. It is not having enough lanes and/or population density. The way the city is planned and executed depends too much on money than on the welfare of the people.

[@yorslam]

tweetsauce

[@deansheffy8946]

Slinky

[@teddyjeddy1998]

im going to do this because im a troll

[@ClearPower]

Let's bring in Thanos i bet he can solve it..

[@holographic4916]

what kind of idiot hits the break on a highway lol just drive straight. traffic shouldn't exist

[@MrAkilio]

heres the theoretical math which proves this phenomenon math.mit.edu/projects/traffic/

[@randgate]

Lame fake horns

[@bokdcutie]

Traffic is caused by wamen with poor driving skills.

[@Engineer9736]

Or Ians with poor English skills

[@carmant]

So. Badly. Animated.