Archive for March, 2010

You know who you are.

But seriously, this etymological foray into the history of the word chauffeur has me, well, stoked.

Sorry, one of my favorite bits from Henry V. But reader Matt writes in with a confusing (at least to him, and to me upon first glance) yield situation at an intersection in Pennsylvania (Google Map it at: “matsonford road, west conshohocken pa.” Given the mixed messages of the signage, what sayest thou, readers — will you yield?

Matt lays out the scenario below:

When I saw the headline, I thought it was referring to where the Santa Monica freeway intersects with the 405, but alas, it’s a novel interchange configuration, suitable for the Slough-ey, office-park-ey, pedestrian-free places of the world, perhaps some kind of next-century CFI.

(thanks Phil)

Next up for Streetfilms: Ray Kelly?

(Thanks Alan)

As any Traffic reader knows I have a jones for “collective animal mobility.” I recently across an interesting paper, “Traffic and the visual perception of space,” by Petr Šeba, a physicist with the University of Hradec Králové in the Czech Republic.

As he notes:

During the attempt to line up into a dense traffic people have necessarily to share a limited space under turbulent conditions. From the statistical point view it generally leads to a probability distribution of the distances between the traffic objects (cars or pedestrians). But the problem is not restricted on humans. It comes up again when we try to describe the statistics of distances between perching birds or moving sheep herd. Our aim is to demonstrate that the spacing distribution is generic and independent on the nature of the object considered. We show that this fact is based on the unconscious perception of space that people share with the animals.

Here’s how it was done:

In order to verify this hypothesis we organized a simple experiment with pedestrians in a narrow corridor. Using two light gates we measured their velocity and the time interval that elapsed between two subsequent walkers. This enables us to reconstruct the mutual distances and evaluate the distance probability density. The same device and method was used also for a sheep herd moving through an aisle between two near yards. The third source of data are cars moving on a highway in a dense traffic. The velocity and time stamps of the individual cars were obtained by induction loops placed below the roadway.

The probability distribution of distances between objects in all these cases was essentially the same (suggesting, according to the author, a universal mechanism for estimating time-to-collision and its avoidance). Something to consider in those long holiday security lines at the airport.

There were only a few flies and wasps in that first trap at Tallulah. But over the next five years, the researchers flew more than 1,300 sorties from the Louisiana airstrip and captured tens of thousands more insects at altitudes ranging from 20 to 15,000 feet. They generated a long series of charts and tables, cataloguing individual insects of 700 named species according to the height at which they were collected, time of day, wind speed and direction, temperature, barometric pressure, humidity, dew point, and many other physical variables. They already knew something about long-distance dispersal. They had heard about the butterflies, gnats, water striders, leaf bugs, booklice, and katydids sighted hundreds of miles out on the open ocean; about the aphids that Captain William Parry had encountered on ice floes during his polar expedition of 1828; and about those other aphids that, in 1925, made the 800-mile journey across the frigid, windswept Barents Sea between the Kola Peninsula, in Russia, and Spitsbergen, off Norway, in just twenty-four hours. Still, they were taken aback by the enormous quantities of animals they were discovering in the air above Louisiana and unashamedly astonished by the heights at which they found them. All of a sudden, it seemed, the heavens had opened.

That’s from Hugh Raffles’ new and absolutely delightful book, Insectopedia, which happily joins May Berenbaum, et al, on my entomology shelves.

Not where you’d expect: Rural Finland.

More at Books from Finland, via the always reliable Things:

The Finnish model of forestry has been hailed as an economic success story, but it has also caused large-scale devastation of natural forests and huge greenhouse gas emissions from forests, forest soils and peatlands in many different parts of the world, from Finland to Brazil and Indonesia.

Why have Finns, an ancient forest people, been so eager to export clear-cutting to other parts of the world?

Via Ryan Oakley I was reminded of this clip from MI:3, which I’ve used in a few talks to some amusement. Does this sort of thing ever happen to, say, Bruce Schaller?

Via Nudge, a fascinating article about trying to prevent railway crossing deaths (by pedestrians) using a variety of behavioral cues intended to counter perceptual biases and guide decision-making:

From all this research, Shroff identified three major decision-making principles in operation on the Wadala tracks. “One is a combination of the Leibowitz Hypothesis and the Looming Effect. Large objects appear to move slower than small objects, and people can’t judge their speed,” she says. “Another is the Cocktail Party Effect: The brain isn’t wired to follow two conversations, or do two activities simultaneously. If there are two trains on adjacent tracks, you’ll register one, but not the other.” The third is simply a flight response—a tendency to run, which minimizes good judgement.

At the station itself, Krishnamurthy points to the final intervention—a three-panel photo of a rather alarmed man being gradually run over by a locomotive. This morbid frieze is positioned exactly at the two points where the temptation to cross is powerful, designed to subtly counter the flight response.
“It’s intended to elicit an appropriate emotional memory,” Krishnamurthy says. “We look to faces to figure out situations, so his face is central. We repeated the image, because it catches the eye. And it has to be life-size, not larger than life, because it shouldn’t intrude into the conscious. It should work at an unconscious level.”

An interesting point of departure from this graph that’s been making the rounds of the U.S. packed into one Brooklyn-style New Hampshire is one I’ve mentioned before, via the work of Brian Pijanowski:

If the percentage of parking lot area in the county (0.44%) is scaled to the area occupied by the conterminous United States, the entire states of Connecticut, and Massachusetts (12,550 + 20,305 = 32,855 km2 ) would be paved over with parking lots.

To put this another way: The American parking lot currently consumes much more space than the entire country’s population would if it were scaled to Brooklyn-style density.

Hello neighbor!

I came across this line in William Sims Bainbridge’s new book, The Warcraft Civilization, on the social sciences of the virtual World of Warcraft:

Some long-distance travel is free, using the public ship, zeppelin, or teleportation systems. But much flight from point to point has moderate costs. Maxrohn found that a nonstop flight from Light’s Hope Chapel in Eastern Plaguelands to Nethergarde Keep in the Blasted Lands costs thirty-one silvers and fifty nine coppers. However, it is possible to fly from Light’s Hope to Stormwind for nine silvers and sixty-three coppers, and from Stormwind to Nethergarde for seven silvers and forty-seven coppers. Thus, stopping at Stormwind saves fourteen silvers and forty-nine coppers, or slightly over 45 percent.

It’s intriguing that this rather echoes the market for using frequent-flier points — i.e., it will cost you less for a flight with stops. This raises all kinds of interesting questions: What dynamics account for the pricing (e.g., does greater network traffic increase the cost of travel) and the network disequilibrium? Why would anyone pay to travel if one can teleport for free (a question for Patricia Mokhtarian)? Is there a Kayak-type application for analyzing the costs of travel, or is it all trial and error? Do people interact on the public ships and zeppelins? Is private flight much faster than the public options (presumably teleportation is instantaneous), and is there a “last mile” or connectivity problem with the public options (so to speak)? And lastly: Are there any travel externalities in World of Warcraft?

Via today’s New York Times:

At relatively slow rates of flow, turbulence is intermittent — it’s pushed along, Dr. Hof said, by smooth-flowing fluid behind it. By studying flows in a special glass pipe and modeling them on a computer, Dr. Hof and his colleagues realized that introducing an eddy into this smooth-flowing zone would eliminate the turbulence in front of it. “One turbulent eddy kills the other,” he said. As long as the pipe is straight, the flow should then remain smooth.

One wonders about any potential analogies to traffic here — the not quite perfect comparison that springs to my mind is the work, via people like Dirk Helbing and Serge Hoogendoorn, that shows in pedestrian escape modeling that introducing an obstacle into an exit opening actually improves the rate of discharge.

Any hardcore flow/sim types have any thoughts?

Kids these days.

Via David Hembrow.

For those who have requested or otherwise been interested, I’m now further larding the datasphere via Twitter.

I won’t promise any epiphanies, but you can follow here should you desire (and this will likely serve as a transition space to the next book — no, it’s not underway yet!)

I’m slow to get to this, but this incredible case of a sideways high-speed shunt in the U.K. is about as dramatic a case you can imagine of how divorced a motorist can be from the world around him.

Via the BBC:

In a bid to release her vehicle, she said she pulled on the handbrake and flashed her hazard lights to try to catch the driver’s attention, as well as that of other road users, but she said it took the lorry driver nearly a minute to notice her.

When he did he was “all over the place”, Mrs Williams said, and finally managed to bring both vehicles to a stop on the hard shoulder.

Charles Komanoff reports from Gauangzhou:

With double-digit rises in car ownership and the city’s relentless expansion outpacing even the rapid provision of transit, the idea of charging a toll to drive into Guangzhou’s city center is gaining traction. The rationale is clear: drivers who pay only for their own lost time but not for the time their trips take from other drivers have little incentive to prioritize trips by car.

The stance of the domestic transportation experts here has been one of cautious interest: appreciation of congestion pricing as a virtually fail-safe tool, tempered by awareness that politics leaves little room for error in designing the toll, choosing the tolling technology, and marketing the program.

Car advert as classist social commentary. Think of it as an FSBO for the ASBO crowd. Reading it and the comments puts me in mind of the immortal David St. Hubbins: “It’s such a fine line between clever and stupid.”

The ad is here.

(Thanks to the indefatigable Alan)

A few things came in after my Slate column on planes landing on roads.

Reader Craig advises on a crowdsourced, Google Map-driven application he has started called Emergency Runways, which informs pilots of potential landing spots. He notes he’s in conversation with some GPS companies to put “vetted” runways into systems, so pilots could press something like a “nearest” button in the event of a forced landing.

And on a stranger, more grim note, a jogger was killed on the beach in South Carolina by a plane making an emergency landing (the pilot’s window was covered in oil).

“There’s no noise,” said aviation expert Mary Schiavo, a former inspector general for the National Transportation Safety Board. “So the jogger, with his ear buds in, and the plane without an engine, you’re basically a stealth aircraft. Who would expect to look up?”

Satellite Car Chase from Honest Directors on Vimeo.

The budget for the aerial perspective move chase scene just went down dramatically.

(thanks Alan)