VIDEO: Traffic jam shockwave recreated in experiment
Click above to watch video
Shockwave traffic jams -- the kind where you slow down and speed up (with others behind you doing the same thing) -- have finally been recreated in a controlled environment (woo-hoo!). Theories about the causes of traffic jams have been computer modeled before, but here hasn't been a live demonstration of how a body of traffic goes from highway speeds to a dead stop -- for no apparent reason -- until now.
A team of Japanese scientists put 22 cars on a circular track and told them to drive about 20-MPH. Sure enough, a few laps in, uneven gaps appeared between the cars. Then a group of cars got bunched up. The people at the back of the bunch sometimes had to come to a stop. The car at the front of the bunch would lurch away... only to rejoin the back of the bunch on the other side of the circle.
Now that the phenomenon has been recreated in "lab" conditions, the greatest minds of our generation can get to fixing it. Or, not really, since the cause of shockwave jams is conclusively shown to be -- tada! -- human error. Some folks just can't go with the flow when traffic needs it most. So while fixing human error might not be on the cards, at least there's some hope now for traffic jams. Watch video of the artificial shockwave traffic jam after the jump. Thanks for the tip, Ben!
[Source: New Scientist]
Reader Comments (Page 1 of 2)
PiCASSO 10:36AM (3/21/2008)
It only takes one person to be distracted by something and cause him to brake late, which results in what we see here. Driver error... grr.
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samit 10:45AM (3/21/2008)
The driver at the very bottom of the screen got so frustrated of the traffic jam that he/she simply drove off the track into the grass. LOL
chiohmann 12:45PM (3/21/2008)
What i dont get it nobody drove off.
Seoultrain 1:19PM (3/21/2008)
car already drove off at the start of the video. it's at the very bottom, and you can see the tire tracks.
paul34 1:24PM (3/21/2008)
It's not even braking late. It is those idiots who insist on slamming the gas to move up two inches and then slamming on the brake again. Let a distance build and then just idle up! It's so simple and avoids traffic waves.
Same with following distances. Long distance means you don't have to brake all the time. Also, just because someone's brake lights come on doesn't mean they're braking significantly. So don't hit your brake everytime you see brake lights, idiots.
Or, the worst of the bunch - rubberneckers. See an accident? Move the hell over, and KEEP DRIVING.
Or, merge lanes. If everyone allowed one person in each (by keeping a long following distance), traffic wouldn't even slow down and furthermore, there wouldn't be any cutting off or near accidents. Instead, people fight people merging for as long as possible. What the hell are you doing?
Traffic is due to people's stupidity and lack of common sense.
mike k. 10:38AM (3/21/2008)
Oh but we can fix it. Remember the story about new systems that will stop your car before you rear-end someone. Now we could take that system and use it both ways in traffic, to have people speed up when they should and slow down at the right interval to not make these traffic jams. This of course means people will temporarily not be in control over their acceleration, but thats just a MINOR concern.. of course then all cars would need to have this same system/algorithm to make it work.
Oh well screw it.. maybe we all need to buy beaters and just ram the people irrationally slowing down.. thats the ticket.
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Paul H. 10:48AM (3/21/2008)
Nice, a scale model of the Washington, D.C. area beltway.
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White Goodman 1:13PM (3/21/2008)
Hah.... I had to drive through that mess Wednesday afternoon. Kept looking for an accident or construction as a cause for the sub-15mph speeds, but no..... just idiot drivers to blame.
Seoultrain 1:20PM (3/21/2008)
I've never seen traffic like DC traffic (I've been in NYC, SF, Seattle). I feel bad for you guys.
Kaptain75329 4:27PM (3/21/2008)
Seoultrain : There's a reason we call it the 495 parking lot around here. :-P
Jeff the Baptist 10:51AM (3/21/2008)
There is actually a way to fix this on the small scale: have enough excess capacity that a single driver error won't have a strong enough effect on traffic to cause a wave. Keeping drivers moving at different speeds separated (as with keep right laws) should help prevent this as well.
Unfortunately it won't fix the larger traveling traffic compression waves caused by accidents and gapers delays. Once all lanes of traffic are effected, you're screwed.
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Randy 11:12AM (3/21/2008)
I've been doing something different off and on for about a month. When I get in traffic going home from work and its stop and start, I slow down to a crawl and let the space between myself and the person in front of me extend. There's much less braking this way. over 80% of the time I never touch my brakes again if I pace it out. There is some letting off the gas but there is mostly no stopping anymore.
I've been watching my rear view mirror as well. When I ascend a hill on the highway at 20MPH i can see the traffic flow behind me moving steadily and in the far back I can see it still messed up so I think the effort gets screwed up about 100 cars back.
I don't do this for everyone behind me, I do it because I don't want to stop and start 200 times on my trip home. I'd rather coast!
I also have a solution to rubber neckers (even me). When there is a traffic accident or police pullover or something, all the signs on the highway that are programmed to say stuff (the lit ones) should alert everyone things like.
"It's only a fender bender - Move Along"
"There's no body on the side of the road - Keep Moving"
"It's a DUI bust - And He's From Another Country So You Don't Know Em"
"Severed Head - Must See"
"Brought to you by ......." lol
Ya know?
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Dmitriy 11:35AM (3/21/2008)
I agree, and do the same as well. Except one cant help that most drivers can not think past their front bumper and ride your rear end and pass you only to slam on the brakes just in front of you and restart the whole wave again. Sad thing is - they think they got somewhere and that this is how it should work.
Unless technology gets safe enough (and it will eventually) the only cure for this is driver education.
Seoultrain 1:29PM (3/21/2008)
yep, never touch your brakes on a highway. However, it gets tricky, because late braking is the worst thing that you can do, so you have to anticipate and brake as early as possible if needed.
Kevin 11:15AM (3/21/2008)
Somehow I can't help but think that this problem would be greatly reduced (not eliminated, but alleviated) if people would drive in the lane that is appropriate for the speed that they're driving at, and not sit in the far left lane and then match the speed of the people in the other lanes so nobody can pass. Or, for that matter, sit in the fast lane while driving the speed limit or below.
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Doug 11:17AM (3/21/2008)
I bet the backup occurred because the people eventually got dizzy and disoriented from driving in that little circle.
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Ted 11:22AM (3/21/2008)
NASCAR!
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Nathan 1:20PM (3/21/2008)
Nascar turns left, so this is clearly Australian Nascar, get your motor sports right!
Ted 3:15PM (3/21/2008)
D'oh!
Todd 11:39AM (3/21/2008)
OH BUT WE CAN FIX IT! Raise the licensing requirements above the current "Zero skills gets a driver's license" up to say something similar to the Bob Bondurant Driving School and that will fix most of it.
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