Experiment Shows Traffic 'Shock Waves' Cause Jams

Galactic_grub writes "Japanese researchers recently performed the first experimental demonstration of a phenomenon that causes a busy freeway to inexplicably grind to a halt. A team from Nagoya University in Japan had volunteers drive cars around a small circular track and monitored the way 'shockwaves' — caused when one driver brakes — are sent back to other cars, caused jams to occur. Drivers were asked to travel at 30 kmph but small fluctuations soon appeared, eventually causing several vehicles to stop completely. Understanding the phenomenon could help devise ways to avoid the problem. As one researcher comments: 'If they had set up an experiment with robots driving in a perfect circle, flow breakdown would not have occurred.'"

That's why I never use my brakes

[Reality Master 201]

I have respect for my fellow drivers, and only use the gas pedal. Breaking is for pussies.

Re:Brakes. Not breaks.

[wattrlz]

Well, it's an understandable mistake. They're, "Breaking" the flow of traffic, after all.

Faulty drivers

[mhifoe]

caused when one driver breaks

Maybe some more reliable drivers would have made the experiment more successful.

"caused when one driver breaks"

[Kingrames]

Well there's your problem right there.

You wouldn't have this problem if you wrote your own drivers.

dark helmet

[twoboxen]

I knew it... I'm surrounded by *ssholes.

Keep braking, *ssholes!

prehistoric

[cinnamon colbert]

I can't find the reference, but clearly remember reading about the physics of traffic jams 20 years ago.
there are a lot of complex things going on, but two simple principles stand out
  when someone ahead of you brakes, you need some time (distance) to react
if you are far enough away, you will slow the same amount as the person ahead of you
if you are to close to the vehicle ahead of you, then your reaction time is such that you will over compensate and over brake; the same to the person behind you and so forth
the trnasition between these two regimes is quite sharp

second, people slow for any distraction - a bright sign, a hill, whatever....

Research in Japan

[Anonymous Coward]

I'm now really tempted to go to Japan. I'm pretty sure I couldn't get that experiment past human subjects review in the U.S.

Re:That's why I never use my brakes

[Anonymous Coward]

Apparently spelling is for pussies too.

Re:Brakes. Not breaks.

[0100010001010011]

Dude, don't loose your mind. I was just making a joke up they're. If you come off you're rocker that quickly I wonder what you have up their in your noggin. Sounds like a screw lose or something. I mean I didn't try to effect you in anyway, but now look how you've gone and disrupted the affect the original poster had. Here me out, there are a lot of people that are knew hear. You should calm down than come back later.

(stolen from myself [tdiclub.com])

Re:Brakes. Not breaks.

[The Night Watchman]

Damn you, sir! That post managed to hurt my brain even when I knew it was meant in jest. Grammar... terrible... must... correct...

Re:That's why I never use my brakes

[Steve525]

Actually if you're following at the correct distance...

You, sir, have never driven on any of the highways near NY city. If you had, you would know that it is impossible to drive the correct distance behind the car in front of you. It's not merely that you'd be only person on the highway doing such a thing (annoying the cars behind you); it's that those car lengths will instantly be taken up by people cutting in front of you. You would then be forced to slow down, and the process would repeat until you find yourself driving backward.

Re:Brakes. Not breaks.

[Rocketship Underpant]

I always thought that people who drove aggressively (well) were smoothing out the "shock waves" by avoiding congestion and filling gaps where traffic was too spaced out.

Re:it's mindboggling

[edittard]

Perhaps Slashdot stories have a similar mathematical structure - even the dupes come in waves...

Re:Even older than that

[AP2k]

Thus, we see the wave propagation in science articles.

Re:That's why I never use my brakes

[Sanat]

"Oh, and that turn signal thingy...try using is occasionally."

Here in Appalachia if a vehicle has its turn signal on then it usually indicates that the vehicle was shipped from the factory that way.

Re:Brakes. Not breaks.

[Smidge204]

I always kinda fantasized about a switch that did the following:

  -Activate the brake lights
  -Activate a set of hydraulics to boost the read of the car up an inch or two
  -Release a little smoke from a point near the rear wheelwells
  -Play a loud screeching sound from a loudspeaker mounted under the trunk

Simulated emergency stop! Should give those tailgaters a reason to back off...
=Smidge=

Re:Brakes. Not breaks.

[Anonymous Coward]

Posting Anon, not losing mod points...

Here is a little trick that I learned a long time ago. To deal with slow drivers in the left lane, is basically giving them a taste of their own medicine. The next time you find yourself stuck behind a slow driver in the left lane, when possible, pass him/her. And position your car just before their car, and drop your speed to an obnoxiously slow speed. Oh, and when they try to ease over to pass you, don't let them. Do it for a few minutes, just so they know how it feels.

It beats road-rage and it could actually make you feel good about yourself, in an asshole-ish kinda way.

Re:That's why I never use my brakes

[mapkinase]

You think you are smart, ah? I bet you would not be able to do that while talking on the phone and sipping coffee at the same time.

Gotcha!

Re:That's why I never use my brakes

[mapkinase]

So basically you are proposing to pay attention to driving during driving? But how I can drink coffee and talk on the cell phone at the same time if I am paying attention to the road? Your proposals are outrageous!

Re:Brakes. Not breaks.

[Robber Baron]

I was thinking more along the lines of a depth charge style launcher that would roll a bowling ball out the trunk or tailgate when a button was pushed.

Re:Not that simple

[internewt]

Its always a BMW because they think they own the fucking roads. They also rarely indicate, and if they do it'll be incorrectly.

Mercedes drivers are awful too, but has anyone noticed just how much of a wanker the average Audi driver seems to be these days? Many car buyers are fashion victims, and I think some of the "cooler"[1] BMW drivers are moving to Audis.... I don't think its a co-incidence that the newer Audis look more aggressive than the BMWs.

[1] shallower or wankerer

Re:Brakes. Not breaks.

[RiyazShaikh]

>> Every time you touch your brake for any reason, God kills a kitten
There... that should have the right effect.