All the roads that’s fit to print

Paul Raven @ 15-11-2010

Gasp in awe at the crazy range of stuff we can ‘print’ nowadays… and then try not to think too hard about the economic job-destruction implications as you watch video footage (which, given it was linked to by BLDGBLOG, I’m assuming isn’t some sort of clever spoof) of a machine that can ‘print’ a paved Tiger Stone road as easily as laying a long roll of linoleum:

Geoff Manaugh’s post linked above already mentions China Mieville’s Iron Council as a fictional almost-precedent, but it’s such a powerful conceptual image that I think you could get more stories out of it without treading on anyone’s toes…

Stuff-we-can-(theoretically)-print bonus content: we’ve mentioned transplant organ printing before, but here’s an explanatory video from the Biophysics Lab of the University of Missouri-Columbia [via Fabbaloo]:

The Free Freeways

Tim Maly @ 20-01-2010

Excerpts from “Asphalt Veins – The Freeway States” Published in NEWStream and syndicated to all ReutAssoc membersites (retrieved December 21 2012 @ 13:34).

Ysterplaat Airshow 2008
Creative Commons License photo credit: mallix

It was no great surprise when the highways seceded. Continue reading “The Free Freeways”

Solar roadways

Tom James @ 14-09-2009

solarroadwaysOne of those brilliant ideas that I wish I had thought of first: paving roadways with electricity-generating solar cells. Idaho-based startup Solar Roadways have been awarded $100 000 to develop their road-based solar panel technology:

The 12- x 12-foot panels, which each cost $6,900, are designed to be embedded into roads. When shined upon, each panel generates an estimated 7.6 kilowatt hours of power each day. If this electricity could be pumped into the grid, the company predicts that a four-lane, one-mile stretch of road with panels could generate enough power for 500 homes. Although it would be expensive, covering the entire US interstate highway system with the panels could theoretically fulfill the country’s total energy needs.

Furthermore the panels would create road markings with embedded LEDs.

It occurs to me that roads are the perfect media for ground-source heat pumps as the constant passage of cars heats up the road surface, even on cold days. When a new road is laid down (or an existing road is resurfaced) you fill it with the necessary pipework and plug it into the heating systems of nearby houses. Heat pumps would be more useful in urban areas of more northern, colder countries than solar panels due to shorter days in the winter.

[via Physorg][image from Physorg]

Jamitons – the math of phantom traffic jams

Paul Raven @ 23-06-2009

traffic jamHave you ever wondered what causes those seemingly cause-less traffic jams the occur pretty much anywhere with a reasonable density of motor vehicles? Sure you have – but you probably didn’t have the mathematical chops to investigate further, unlike the geeks at MIT:

The mathematics of such traffic jams are strikingly similar to the equations that describe detonation waves produced by explosions, said Aslan Kasimov, a lecturer in MIT’s Department of Mathematics. Realizing this allowed the reseachers to solve traffic jam equations that were first theorized in the 1950s. The MIT researchers even came up with a name for this kind of gridlock – “jamiton.” It’s a riff on “soliton,” a term used in math and physics to desribe a self-sustaining wave that maintains its shape while moving.

The equations MIT came up with are similar to those used to describe fluid mechanics, and they model traffic jams as a self-sustaining wave.

“We wanted to describe this using a mathematical model similar to that of fluid flow,” Kasimov said.

The researchers hit upon the equation after an experiment by Japanese researchers demonstrated the formation of jamitrons on a circular road. In that experiment, drivers were instructed to travel 30 kilometers an hour (18.6 mph) while maintaining a constant distance between cars. It didn’t take long before disruptions occurred and phantom jams formed. Denser traffic brought quicker jams.

The MIT team found speed, traffic density and other factors can determine conditions that will lead to a jamiton and how quickly it will spread. Once the jam forms, the researchers say, drivers have no choice but to wait for it to clear. The new model could lead to roads designed with sufficient capacity to keep traffic density below the point at which a jamiton can form.

Now, after reading that article I found myself thinking “wouldn’t some sort of peer-to-peer traffic management system be better than building bigger roads?” So imagine how smug I felt when this article turned up a few days later:

The hope, of course, is that by understanding traffic jams we can learn to prevent them. Tom Vanderbilt, in his authoritative book Traffic, describes a simple experiment performed by the Washington Department of Transportation that involved a liter of rice, a plastic funnel, and a glass beaker. When the rice was poured into the beaker all at once, it took 40 seconds for the funnel to empty; the density of jostling grains impeded the flow. However, when the grains were poured in a gradual stream, it took only 27 seconds for the rice to pass through. What seemed slower actually turned out to be 30 percent faster. This helps explain why traffic engineers are so eager to install red lights on highway onramps: By slowing traffic before it enters the concrete funnel, they hope to prevent the road from exceeding its critical density.

I’d be willing to go out on a limb here and suggest that while vehicles are still driven manually by fallible and inherently selfish human beings, traffic jams are inevitable. The only way to truly control the side-effects of human behaviour are to take them out of the picture entirely – and while there are very few situations where I’d advocate such a thing, road traffic is one of them. [image by timsnell]