Scientists replicate traffic-jam “shockwaves” in real-world experiment

This is fascinating to watch: A team of Japanese researchers have created “shockwave traffic jams” that replicate the dynamics of real-world highways.

For 15 years, researchers have known that traffic jams can emerge out of the blue. All it takes is for one driver to momentarily slow down, at which point the person behind him hits the brakes, forcing the person behind him to hit the brakes even harder, and so on, and so on. One teensy butterfly flaps its wings, and pretty soon the whole damn interstate’s a mess. If you’re in a helicopter, you can watch the “shockwave” of slowed-down cars propagate backwards through traffic like a wave through water. Physicists have long produced eerily accurate computer models that replicate this phenomenon precisely. But because it’s pretty hard to commandeer an entire highway for the purposes of research, no one has ever replicated the phenomenon in a real-world experiment.

Until now! The Japanese team got a cluster of vehicles to drive in a circle. As the New Scientist reports, here’s what happened:

They asked drivers to cruise steadily at 30 kilometres per hour, and at first the traffic moved freely. But small fluctuations soon appeared in distances between cars, breaking down the free flow, until finally a cluster of several vehicles was forced to stop completely for a moment.

That cluster spread backwards through the traffic like a shockwave. Every time a vehicle at the front of the cluster was able to escape at up to 40 km/h, another vehicle joined the back of the jam.

The shockwave jam travelled backwards through the ring of vehicles at roughly 20 km/h, which is the same as the speed of the shockwave jams observed on roads in real life, says lead researcher Yuki Sugiyama, a physicist in the department of complex systems at Nagoya University.

“Although the emerging jam in our experiment is small, its behaviour is not different from large ones on highways,” he told New Scientist.

Check out the video of the experiment. Towards the end, the shockwave becomes deliciously mobile — you can really see it moving backwards.

This also puts me in mind of William Beatty, the electrical engineer who — while stuck in traffic in 1998 — figured out a way to hack traffic jams and erase them. Basically, when he was stuck in a jam, he’d slow down until he had a really large amount of space between him and the car in front of him. Then he moved forward in at very slow, uniform speed, so that he no longer stopped and started. Sure enough, the wave stopped at him: Everyone behind him began driving at a uniform 35 mph. “By driving at the average speed of the traffic around me, my car had been ‘eating’ the traffic waves,” he wrote. The only problem, of course, is that he himself was stuck traveling at the average speed of the wave in front of him, which — at 35 mph — is pretty pokey.

(Thanks to Greg Sewell for this one!)

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(via collision detection.)

About an intriguing urban computing assemblage

The recent story of Google cars causing stir in Rome still makes me wondering about the perception of so-called “urban computing” and citizens. To put it shortly, the problem was basic: Google recently brought in black cars in Rome that take pictures for the Google Streetview project (yes at some point you have to physical artifacts taking PICTURES of streetviews, it’s not just virtual). BernhardWarner for the timesonline hence reports the following people’s reaction to these black cars:

“On cue, pedestrians shuffled off the street and into bars, out of sight of the offending vehicle, no doubt wondering if these are the new intrusions that must be endured after a sudden shift to the right. Your correspondent managed to snake through a queue of cars at a traffic light to get a better look at the vehicle that upset so many mid-afternoon espressos.
(…)
Just then the Google car swung left and I followed, in a very slow pursuit. The identical scene unfolded before me: Romans stumbling into shops and bars, hoping to be out of view of the camera’s lens“

In a sense, they perceived it as “a new type of video surveillance vehicle”. I won’t enter into the details of the explanation provided by the timesonline (the election of a right-wing mayor… who wants to promote tough-on-crime platforms) but this situation seems certainly revealing of a troublesome relationship between technological assemblage.

The picture of the google cars in the Netherlands made by Lars van de Goor shows how the whole pack can be intimidating:

Why do I blog this? what I find interesting here is less the perception of a service (that can be articulated as “urban computing”) but instead the sort of experience of the infrastructure needed to provide a service. A flock of all-similar black cars wandering around the city with huge camera-devices may indeed by an intriguing experience as it may came out from the blue. Will we see more of this sort of encounters in the city of the near future?

Btw, Mauro were in you in Rome? have you seen this?

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(via pasta and vinegar.)

The Human Car – Powered by You: “

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Ford Canada has made a new commercial featuring people. I know, that doesn’t sound too special – most commercials have people in them. But not like this… The Ford commercial features only people, and yet what you see is 3 cars.

Take a look for yourself…

And… here is the video:

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Not to mention – a behind the scenes look:

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Wait a minute!

But, then somebody yells out ‘wait a minute… Haven’t we seen this before?’ No, actually, you haven’t. I agree that this is not first time a car manufacturer has used human bodies to create car shapes and body art.

Below is, for instance three similar ads from Hyundai and VW and BidWest. The special thing about the Ford ad is that it is not a ‘shadow trick’. This is 3D art – not 2D ‘shadow’ art.

Both types are very cool – and mind-boggling in an exciting way. I just happen to like the 3D type better.

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Note: Yes I own and drive a Ford every day, so I might be slightly biased.

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(Via Baekdal.com.)

The Magic Roundabout, Swindon: “

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(Via Life, Landscape and In between.)

APU Abstract Painting Unit

AbstractPaintingUnit (aka APU) is a self-contained robotic abstract painting artist. APU senses and interprets the changes in its environment and expresses its computational processes by spraypainting different colors in infinite patterns on big sheets of paper layed on the floor. The audience plays an integral role in the composition of the paintings as their presence and actions influence the painting process by affecting the sensor data that APU continually collects. APU is activaly sensing presence, movement, light intensity and ambient sound amplitude. APU’s body is made mostly from recycled materials. Its former purpose was a plotter printer for an architect.

[tags]robot, piainting, tags, car, printer[/tags]

Open Source at 90 MPH

BusinessWeek asks, can we build an open source car?

“Inspired by Linux, the OScar project aims to build a car by tapping the knowledge of a volunteer team. It won’t be an easy ride, but their journey is important…

So here’s a question: Can open-source practices and approaches be applied to make hardware, to create tangible and physical objects, including complex ones? Say, to build a car?”

– Link.

There are hundreds of open source hardware projects going on – just as complex or more so than cars. But cars go on roads, require approvals, it’s a little more than making an open source hardware arduino project. The hot-rod culture shared everything and it was completely common to build a car from scratch in many enthusiast communities in the 50s, that is still going on today.

Here’s a DIY Fuel Injection Conversion using open source engine management – Megasquirt is an affordable, open-source, DIY engine management computer that you assemble yourself. A large community of developer/users provides for constant development, and great free support – Link.

Short answer, of course it can – that doesn’t mean it will happen, or the value/demand is there, but there’s a lot of benefit in an open approach for some hardware and processes.

What do you think? Post in the comments.

From the pages of MAKE:

• The Open Source: Design Brief: The time is right for a true people’s hybrid vehicle. The web is peppered with how-to sites for converting your old car into an electric vehicle, but why not develop SourceForge-style documentation for an open source hybrid? MAKE 01 – Page 44. Subscribers–read this article now in your digital edition!

[Read this article] [Comment on this article]

Originally from MAKE Magazine, ReBlogged by Jonah Brucker-Cohen on Dec 14, 2006 at 07:22 AM

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(via Eyebeam reBlog.)

[tags]opensource, car, vehicle[/tags]

Beijing’s “No Car” Days: How to Win Friends and Not Influence Traffic

In a booming mega-city where 1,000 new cars hit the streets everyday, encouraging its recently-minted drivers to opt for public transportation is not an easy task. Leave it to Beijing. Over a quarter of a million of the city’s drivers have pledged to stop driving for one day over the next week in an attempt to ease traffic and improve air quality for the thousands of dignitaries attending the city’s Sino-Africa Forum. Along with gathering “no car” pledges by drivers from 476 organizations, including many of the city’s driving clubs and private businesses, the city has ordered 80 percent of the municipal government’s and half of the central government’s vehicles off the roads. They’re even shortening school hours.

Aside from helping to feed China’s hunger for Africa’s raw materials (check this space for more coverage on that soon), the country’s biggest summit in history serves as a convenient dry run for the Olympic Games in 2008, a coming-out party for the city that is set to add 1 million people to the streets. On the one hand, the “no car” day is an impressive and good-spirited initiative, and one you’d be hard pressed to find in any other metropolis. But even if Beijing’s charm offensive (which includes painting its grass green) looks good, “no car” days haven’t had much effect before. And they’re certainly unlikely to reverse the deeper problem: years of shoddy transportation planning that have led to “11-hour rush hours” beneath perpetually mucky skies.

(This post continues on the site please click the title)

(Via Treehugger.)

[tags]ecology, car[/tags]

“The slow inevitable death of american muscle”…

“The slow inevitable death of american muscle” by Jonathan Schipper. Two cars are slowly crashed into one another of the course of a month. The movement is so slow as to be invisible.

(Via VVORK.)

[tags]installation, car[/tags]