Archive for the ‘Congestion’ Category

Over at Politico, I offer an appreciation of the aerial photographs of highway interchanges by the Canadian photographer Peter Andrew.

“What is it that makes the patterns of highway interchanges so captivating? Perhaps we are drawn in by our pattern-hungry brains, mentally tracing the loops and parabolas, looking for connections and symmetries. Perhaps we gain a pleasurable synaptic charge from mastering the routes. Or, in the way the contours of Jackson Pollock’s drip paintings have been shown to follow a strongly fractal logic, perhaps a well-designed highway interchange hits some kind of subconscious geometric sweet spot. (Long before highways, braided knots were figuring into various religious symbologies, and Pictish knot imagery from the Book of Kells seems curiously evocative of modern day interchanges.)”

While certainly sympathetic to the idea expressed by the image above, I was thinking it a bit too high-mindedly smug, too facetious, more of a sentiment than a reality, a phrase great for a t-shirt or cartoon caption but not much grounded in reality.

Then I looked at a random sample of Twitter.

My lips are sealed.

My latest Slate column considers Jarrett Walker’s new book Human Transit and the question of how we can make transit more successful: Make it nicer or more efficient (and do we have to choose)?

As befits someone who has spent decades in small, formerly smoke-filled rooms with civic officials trying to implement working transit systems, Walker is a realist, and Human Transit is a spirited guide—prescriptive but with a righteous dash of polemic—to what we get wrong about transit. “In many urban regions,” he writes, “support for public transit is wide but shallow.” People generally like the idea of transit (as characterized by the Onion headline, “98 Percent of Americans Support Public Transit for Others”), but much of our society’s experience and understanding of transit, not to mention our willingness to pay for it, is limited. The very fact that most of us drive, argues Walker, casts a subtle, but powerful, influence onto transit thinking. “In most debates about proposed rapid transit lines,” he writes, “the speed of the proposed service gets more political attention than how frequently it runs, even though frequency, which determines waiting time, often matters more than speed in determining how long your trip will take.” Drivers don’t wonder when their cars are going to show up.

The Economist picks up the thread over at its Democracy in America blog.

A lot of ink has been spilled over the past few years arguing about whether trolleys are silly atmospheric baubles or a vital ingredient of livable cities. Reading this passage, I abruptly realised why it is that I prefer taking my city’s rail-based transit to taking its buses: the presence of a dedicated rail serves as a visual promise of service. A bus stop stands forlornly in the urban wasteland, offering no real guarantee of the existence of the bus. The figure of the passenger waiting for a bus that may or may not ever arrive is a visual cliche. Trolley tracks and electric lines running down the middle of the street, however, are a promise: a line runs here. It may be ten minutes between trolleys, it may be half an hour, but something is going to come down that line and take you where you’re going. The very expense of creating the line tells you: the government has invested too much in this infrastructure for there to be no service. The rails are, literally, an ironclad guarantee.

My feature on autonomous vehicles is the cover story in this month’s Wired. You can find the story here.

The last time I was in a self-driving car—Stanford University’s “Junior,” at the 2008 World Congress on Intelligent Transportation Systems—the VW Passat went 25 miles per hour down two closed-off blocks. Its signal achievement seemed to be stopping for a stop sign at an otherwise unoccupied intersection. Now, just a few years later, we are driving close to 70 mph with no human involvement on a busy public highway—a stunning demonstration of just how quickly, and dramatically, the horizon of possibility is expanding. “This car can do 75 mph,” Urmson says. “It can track pedestrians and cyclists. It understands traffic lights. It can merge at highway speeds.” In short, after almost a hundred years in which driving has remained essentially unchanged, it has been completely transformed in just the past half decade.

My latest Slate column explores the concept of “rolling speed harmonization” on a Colorado highway.

As one report describes it, speed harmonization “holds that by encouraging speed compliance and reducing speed differential between vehicles, volume throughput can be maximized without a physical increase in roadway dimensions.”

The concept plays, in part, on one of traffic engineering’s core truths: Big speed differentials are dangerous. This is laid out in the “Green Book,” the bible of the American Association of Surface Highway Transportation Officials. “Crashes are not related as much to speed as to the range in speeds from the highest to lowest,” the book states. “Studies show that, regardless of the average speed on the highway, the more a vehicle deviates from the average speed, the greater its chances of becoming involved in a crash.”

As you no doubt have heard, JetBlue has offered $4 flights from Burbank to Long Beach to help Angelenos avoid the “carmaggedon” closure of the 405.

But what if there was a faster way than air travel?

I joined the stable again over at the New York Times’ Room for Debate, this time on the idea of full highway shutdowns.

Just for historical curiosity, here’s my original, somewhat more fanciful (but contextual) submission:

It’s perhaps appropriate that the town that produced Michael Bay should summon such a bombastic bout of overblown apocalyptic fury as the forthcoming “carmaggedon.” Given the life-support functions of the 405 in the L.A. region’s transportation monoculture, perhaps the hype is warranted, but the truth is, highways are closed all the time, and there’s been much study and practice into how to do it most effectively.

The perturbed driver may be asking, ‘why do they have to close the whole thing down? Why can’t they just do it a lane at a time?’ And indeed, any number of strategies have been tried to mitigate traffic impacts during construction, from nocturnal work crews (which has been found to add 6% to the base price of a project) to various incentive plans for road contractors.

But as research by the Federal Highway Administration has shown, closing down a highway entirely means the job gets done, on average, 63 to 95 percent faster than projects that tried to maintain a semblance of traditional traffic. Why? No traffic means no interference from drivers, no work-zone crashes (in 2007, for example, 835 people were killed in work zone crashes) or other bad behavior, not to mention that the trucks hauling materials and workers don’t have to sit in the same congestion as everyone else as they go back and forth.

The secret to making this happen, as is happening in Los Angeles, is to enact a comprehensive “Traffic Management Plan,” with careful study of alternate routes and “network effects.” Implicit in this is to issue a prediction of Nostradamusian direness; to do for weekend driving what Jaws did for ocean swimming (“just when you thought it was safe to go to Santa Monica”).

This reason this generally works is that in any road system, there is a certain amount of elasticity; not every driver on that road has to be there at that time. There may be another route, another mode of travel. Or they just stay home. When highway segments are taken out because of disaster (as in the Minneapolis I-35 W bridge collapse, or the collapse of Manhattan’s West Side Highway) the surrounding roads do not automatically filled up with all the diverted drivers; rather, some traffic “disappears.” To quote two of the main findings of a report analyzing any number of road closures, planned or otherwise, by transport researcher Phil Goodwin and colleagues: “When roadspace for cars is reallocated, traffic problems are usually far less serious than predicted” and “Traffic reduction is partly explained by recognizing that people react to a change in road conditions in much more complex ways than has traditionally been assumed in traffic models.”

When Los Angeles partially closed the 710 expressway for eight weekends, it was able to reduce traffic by 37%. Interestingly, though, traffic was lowest through the work zones the first weekend, and then grew gradually on each successive weekend, as L.A. drivers, in a kind of city-wide learning curve, began testing the drive. In the case of the 405 closure, of course, drivers won’t have that option. There’s no knowing how bad or how good it’s going to be, until you’re in it.

Lisbon’s blood vessels from Pedro M Cruz on Vimeo.

Via Pedro Cruz:

In this work the traffic of Lisbon is portrayed exploring metaphors of living organisms with circulatory problems. Rather than being an aesthetic essay or a set of decorative artifacts, my approach focuses on synthesizing and conveying meaning through data portrayal. This portrayal is embodied in the visualization: The Blood Vessels in the traffic of Lisbon. I use an adaptive physics system to build and manipulate the road network – the thickness, the color and the length of the vessels are excited by the number of vehicles and average velocity in each road. With this system I try to bypass the strictness of contemporary visualizations that depict data accurately through direct mappings.

I have a short piece in the current World Policy Journal in response to the question of the future of the city. In this telegraphic dispatch I addressed the place of the car in the city (N.B.: The piece could also be headlined: ‘An Open Letter to Marty Markowitz’):

We spent much of the twentieth century engaged in a campaign to retrofit our cities to the car. However much this may have seemed to make sense at the time, it now looks more like a misdirected effort to save the city by destroying it. As plentiful as the benefits of individual vehicular mobility may be, the large metropolis can never comfortably accommodate any more than a fraction of its citizens in this manner, and we have learned the consequences of trying to do so. Ever-lengthening commutes have meant degraded public spaces, negative health outcomes, social fragmentation, infrastructure whose maintenance goes underfunded.

In the city of the future, we need to pursue policies that allow for safe, efficient and affordable transport of the many, while recognizing that market-based approaches that so rationally apportion space in the private sector can and should be applied to the valuable urban space — in the form of roads and parking spaces—that cities essentially give away. We need to recognize that streets are public spaces too, and not merely, in the old view of 1930s utopian modernism, channels for moving as many vehicles as quickly as possible. The car will continue to exist, but should be treated as a “renter” of the city, not its landlord. The urban car of the future should be shared, smaller, and slower.

The reason: a collapsed pedestrian bridge.

I was puzzled by this last sentence:

A new bridge, if they decide to build one, could cost as much as 1-million dollars. Gugel says simply installing a traffic light may not be an option because Kearney Street has been designated a barrier street which means students shouldn’t cross it.

Somehow a “barrier street” doesn’t have the ring of something found in the MUTCD, but I may be wrong; any street, in any case, is a barrier with enough car traffic on it. But certainly street designations can be changed?

[UPDATE: See comment below for how the school defines ‘barrier street.’ The website also notes: “Springfield has a number of streets with an exceptionally high volume of traffic. In order to prevent students from having to cross the busiest street, SPS provides free transportation to students who live less than 1.5 miles from school in areas where they must cross a barrier street.”

This reads like something of a fait accompli: These streets are too busy, large, fast, etc. to allow students to walk, so they must be driven (by parents or the school), thus increasing traffic on those busy roads. But one wonders what the larger planning decisions were vis a vis the school siting and the classification of those roads (and one hopes that school is not separated from residences by an interstate highway!). Surely children could cross with relatively, with a road diet, slower speeds, a HAWK crossing or crossing guard?]

Via a discussion at the NRDC Switchboard about a school in Orange County that does not allow students on foot, I was struck by the school’s amazing “Strike Team” document, pictured above, covering the ins-and-outs of the school drop-off.

Is it just me or does this strike you as a sign of a system that is severely out of balance? (and I’m not talking about a “design” problem)

No time to comment on this as, coincidentally, I’m about to leave for the Netherlands, but Bern Grush sifts through the ashes.

Igor Sikorsky was nothing if not optimistic about the idea of a personal helicopter for everyone (an idea that should now send any reasonable person to the brink of terror) in this 1942 article in The Atlantic.

A question certain to trouble you is this: With hundreds of thousands, perhaps millions, of helicopters flying in all directions at once, what about sky congestion and air traffic problems?

Nor will the strict physical examination that now might prohibit many thousands from flying an airplane be necessary. A person who can drive an automobile can fly a helicopter; and a man or woman with middle-aged reflexes is just as safe in one as in the other because the helicopter, as a rule, is always moving slowly when close to the ground. The helicopter owner will have to pass no stricter examination than is—or should be—necessary for driving a motorcar. He should not be color-blind, his vision should be normal with or without glasses. A man or woman with a heart ailment should not drive a helicopter—nor an automobile.

Bill Beaty, the amateur “traffic waves” scientist described in Traffic, writes in to describe his early experiences with Seattle’s new Active Traffic Management System — the “dynamic” system of varying speeds, imported from Europe, which is meant to ameliorate the impact of drivers driving into vast stop-and-go traffic (with the ensuing shockwaves).

Beaty was curious to note that the first part of the project is happening on the very section of I-5 where he first began developing his one-man crusade for traffic harmonization. Here’s how he describes his new commute, which seems to have some of the disequilibrium that new schemes bring:

In the first week it created very strange patterns: huge I-5 jams on
Sunday (when Sunday I-5 northbound has always been empty.) They now seem
to be tweaking their algorithm. Or perhaps drivers are no longer freaking
out. Patterns are still odd, but keep changing over many days.

Another ATMS section is on I-520 …which is right where I first saw the
string of headlights that inspired my first online article. Bizarre
coincidences. Or maybe the bigwigs in the Seattle traffic control
community have all been reading my site? 🙂

Any other Seattle-area readers/engineers care to share their experience?

Like a giant urban hovercraft sucking up traffic in its wake.

Notes dvice.com:

Do you hate waiting behind a bus as it loads and unloads? Well, friend, does China have the craziest solution for you! A Chinese company is looking to build buses so big cars can drive right under them, which will ease congestion. The company is serious about it, too.

Being developed by the Shenzhen Huashi Future Car-Parking Equipment company, the buses are currently planned for Beijing’s Mentougou district, where tracks on the road will make sure they stay straight as cars drive under them — and they drive over cars. Passengers get on and off at elevated stations, as the bus/trolley/what-have-you are so tall.

Interesting, but left unanswered is the question of how to keep cars in their lane.

(thanks Matt)

I was intrigued by Hoboken’s Corner Cars program — essentially a Zipcar style car-sharing program, albeit with even more direct car access — as I had written a bit about here before, so when New York Times “City Critic” Ariel Kaminer said she was going to check it out, I gladly hopped along for the ride (and, maybe it was just lucky timing or something, but I traveled by subway/PATH train from Brooklyn to Hoboken and was there shockingly quickly, even in this age of diminishing service, with no need to brave the city’s legendarily bad parking, pay the tolls, risk my life to NYC’s quantifiably substandard drivers — three cheers for transit!). One interesting question raised by the article (and please note that’s the NYT identifying me as a “traffic expert,” not me — though who isn’t a traffic expert in this town?) is the psychic hurdle of getting people to move past car ownership (in an area, ironically, where many people rent their houses):

There is another obstacle to car sharing in New York, perhaps the biggest of all. Given the paucity of street parking, the expense of garage parking, the traffic, the insurance costs and the toll to vehicle and psyche, New York car owners who aren’t motivated by true need must be motivated by some very strong force of will. So strong, perhaps, that it is impervious to reason. Is there any dollars-and-cents argument that could persuade New York’s discretionary drivers to give up their cars?

“I asked that question back when I was in city government in the ’70s and ’80s,” said Sam Schwartz, the transportation engineer who was once New York’s deputy commissioner of transportation. “In the ’80s we did several focus groups and we tried to find out what made them drive. And a very common theme is that they felt they were smarter than the people down in the tube. They’re the Brahmins. They deserve it.” He added, “I never heard of it anywhere else.”

Not to mention the endowment effect; i.e., once people own something, they feel it’s more valuable than before (even if, of course, the very value plummets the moment you drive the new car off the lot). One question for such programs, and the reason some people buy a car to begin with, is the issue of peak demand for weekends — it’s hard for a spontaneous lets-go-apple-picking trip when all the cars have been rented weeks in advance. And I’m not sure what to do about the alternate-side problem. That’s as intractable as the sabbath, or some force of nature.

Thoughts?

All the votes have been tallied, the loose chads swept off the floor, and “Nimble Cities,” the latest in Slate’s “Hive” series, has drawn to a close.

Check it out here, and thanks to those of you who voted/submitted ideas.

The three leading vote-getters at the Nimble Cities project, explained.

Over at the Slate Nimble Cities project, I discuss the suggestion from a few readers to install moving walkways in cities (as it turns out, an old idea).