Archive for January, 2009

The Hidden Benefits of HOV Lanes

HOV, or “carpool” lanes, are, like everything, the subject of much controversy in the world of traffic. Do they make congestion worse for everyone while only aiding a few? Do they cause more crashes? Needless to say, I could have written a book only on the complexities of the Diamond Lanes (though I’m not sure who would want to read it).

A new paper, “The Smoothing Effect on Freeway Bottlenecks: Experimental Verification and Theoretical Implications,” from Michael J. Cassidy, Kitae Jung, and Carlos F. Daganzo at the University of California-Berkeley, presented at last week’s TRB (I’ll be data-mining the huge trove of research from that conference over the coming weeks), suggests that HOV lanes can provide overall benefits to highway traffic flow — even when the lane itself is underutilized. As with many things about traffic flow, this is beyond the grasp of the average driver, who may simply look over at the HOV lane, see that fewer cars are in it than his own (even if, of course, they’re carrying more people), and begin to grouse about misguided government policy.

The authors looked at a particular stretch of California freeway with a regularly occurring bottleneck, essentially a “merge bottleneck” resulting from increased volumes of entering traffic. A carpool lane becomes active during the morning and evening rushes; and one might be led to think the activation of the lane somehow causes the bottleneck. But the authors note, “previous analysis established that the carpool lane did not contribute to the bottleneck formation and capacity drop. Instead, and as is typical of merge bottlenecks without carpool lanes, the queue first formed in the shoulder lane and then spread to all lanes.” But even as the capacity of the carpool lane began to drop, the researchers observed an interesting pattern: The “discharge” of vehicles from the bottleneck in other lanes actually began to increase.

They looked at video footage, taken from a pedestrian overpass, to figure out what was going on. Interestingly, it was all about changing lanes. In lane 2, as pictured above (the one next to the HOV), drivers made fewer changes in and out of it when the carpool lane was activated (some of those drivers may have previously been jumping back and forth between lane 1, the ‘fast lane,’ and 2).

And here’s where it gets really interesting:

The same phenomenon was observed a few minutes earlier in lane 3, as drivers started
anticipating the impending carpool restriction. The video data reveal that: (i) drivers’ tendencies to avoid the median (carpool) lane as its activation time approached created crowded conditions in adjacent lane 2, starting at about 14:52 hrs; and (ii) although this crowding temporarily induced some drivers to migrate to lane 3, its more significant impact was to dampen the entries made into lane 2 from lane 3; (see Cassidy, et al, 2008). The net result: lane-changing maneuvers between lanes 2 and 3 diminished at 14:52 hrs, as revealed by the boldfaced oblique cumulative curve in Fig. 5. As in the case of lane 2, this reduction in lane changing was accompanied by a sudden and sustained increase in lane 3’s discharge flow.

The authors observed what they called a “smoothing effect.” Drivers were less tempted to change lanes, because there were fewer options available, and the “discharge flows” actually increased. When the carpool lane wasn’t activated, lanes saw anywhere from 9% to 13% worse performance in VPH (vehicles per hour). When considered in terms of “people hours traveled,” the activation of the carpool lane provided a benefit on the order of 30%. The authors note that if this “smoothing effect” is not observed and quantified, long highway delays might be incorrectly attributed to the carpool lane.

What’s interesting about this is that for many of those individual drivers, they were presumably changing lanes to try and improve their own position. But in doing so they were actually reducing the overall performance of the highway.

As the authors note, it’s worth investigating how signage and striping might reduce “disruptive” lane changing. “Disruptive lane changing,” they add, “might also be reduced in some cases by sorting drivers (and vehicle classes) across lanes according to their preferred travel speeds; or in other cases by inducing a more even distribution of flows across lanes.”) We already have seen “variable speed limits” to help smooth out flow in a linear sense; maybe someday we’ll have “variable lane assignment” to smooth it out across the highway.

Posted on Monday, January 19th, 2009 at 11:24 am by: Tom Vanderbilt
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The Latest iPhone App: Crosswalk Warning

A new study in Accident Analysis & Prevention by Jack Nasar, Peter Hecht and Richard Wener finds that pedestrians on mobile phones were less aware of their surroundings and crossed streets less safely (curiously, a sample using iPods seemed less distracted, leading the authors to speculate “perhaps listening to music is a different kind of distraction than listening to words”).

The authors wonder if a technological fix might be appropriate. “Perhaps, the mobile phone or i-pod could alert pedestrians they were approaching a crosswalk or that a car is approaching.” This raises new questions. “If so, would the pedestrian notice and heed the warning?”

Posted on Monday, January 19th, 2009 at 9:20 am by: Tom Vanderbilt
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Curbing ‘Risk Compensation’ in New Hampshire

From the NYT:

“There has often been an appealing vein of common sense in New Hampshire, and that is true of its regulations for people who venture outdoors. The state has always done what it can to rescue hikers and skiers who get lost or in trouble. Since 1999, it has billed them for the costs of rescue if their behavior was reckless. But in July, the standard was changed. If you find yourself in trouble thanks to your own negligence, a lower threshold of responsibility, then you also may end up paying the cost for being rescued.

There is something a little peculiar about the need for a law like this. The New Hampshire Fish and Game Department is hoping not only to recoup some of its rescue costs, but also to warn hikers and skiers that their behavior in nature has consequences.

It’s hard to imagine Americans protesting about having to pay for their ambulance rides after getting sick at home, or injured in a highway crash. But most Americans live lives that are incredibly distant from nature. They often do not understand that venturing into the backcountry means entering a realm of purely personal responsibility.

The greater reach of cellphone service, while making rescue more likely, makes it easier to forget the risks. You can get just as lost while carrying a cellphone — even with good coverage — as you can without it.

That is New Hampshire’s trouble, and it is one of the reasons there is controversy over efforts to expand cellphone coverage in the national parks. That includes Yellowstone, where there are plans to expand the cellphone service that exists near developed areas, like Old Faithful. The backcountry is a world with rules of its own, enforced by nature itself. If that means billing visitors for the costs of their negligence, we say, fine by us.”

Posted on Monday, January 19th, 2009 at 8:10 am by: Tom Vanderbilt
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“I Couldn’t See All that Gas Go Up Like That”

Survivors Of Gas Station Explosion Mourn Tragic Loss Of Gasoline

Much more funny at $4 a gallon, but still…

Posted on Friday, January 16th, 2009 at 12:13 pm by: Tom Vanderbilt
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Change Blindness

Transport for London has already riffed on “inattentional blindness,” without giving props to Daniel Simon — but hey, it’s for the public good, right? But I hadn’t yet seen this take on “change blindness.”

I won’t give it away but I did very poorly.

Posted on Friday, January 16th, 2009 at 12:04 pm by: Tom Vanderbilt
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The “Hudson Miracle” and Safety Culture

The night before the “CFIT” descent into the Hudson River, I was, coincidentally, reading William Langewiesche’s collection on aviation, Inside the Sky. Reading the essay “On a Bombay Night,” about the Air India Flight 855 crash, this excerpt reminded me of just how staggeringly proficient and, yes, heroic, the flight crew’s response yesterday was, to something that had only been practiced on computer screens:

“The pilots knew something, but not what, and they were fully occupied with their confusion. Only the flight engineer clearly saw the errors being made. It was not a nightmare, though that possibility must have crossed his mind. After so many years during which these things had happened only to others, he was now the one actually going down, out of control, crashing. There was no reason for this, and it didn’t feel wild, but the instruments told an undeniable story. And yet he could do nothing but point.

“No, but go by this, Captain!”

Kukar [the captain] did not even answer him. It is impossible to know what denials he was engaged in. Pilots train in simulators to handle all sorts of failures, sometimes heaped on top of the other. But even the best of the simulators require a suspension of belief that never quite overcomes the understanding that they are pretend airplanes built for the purpose of experiencing failures and that no matter how poorly the pilots perform they will walk away unscathed. That, of course, is not true of failures inside the sky, where the first challenge is to suspend disbelief and where the urgency is real.”

The author goes on to conclude that the “underlying cause seems oddly enough to have been the very extent of Kukar’s flying experience… there comes a point in a pilot’s life when the sky feels like home.”

And yet for all the talk of miracles yesterday — for what great water landing success stories are there? — there was also something less sensational at work: Safety culture. Pilots are relentlessly trained in these contingencies, flight attendants are there not merely to be the object of contempt from ill-bred passengers (why can’t I go the bathroom as we’re landing?), the routine announcements may be done out of rote and may indeed seem superfluous, and it’s annoying when the plane is delayed three hours so an indicator light-bulb can be changed, but yesterday’s events showed the real and cumulative value all these things have.

“Safety culture” is the topic of the latest report from UC-Berkeley’s Traffic Safety Center; the newsletter itself is drawn from a longer report prepared by AAA’s Traffic Safety Foundation. As defined by one paper, safety culture, which emerged as a concept in the wake of the Chernobyl incident, “is the enduring value and priority placed on worker and public safety by everyone in every group at every level of an organization. It refers to the extent to which individuals and groups will commit to personal responsibility for safety, act to preserve, enhance and communicate safety concerns, strive to actively learn, adapt and modify (both individual and organizational) behavior based on lessons learned from mistakes, and be rewarded in a manner consistent with these values.”

The report goes on to call for a “traffic safety culture,” something which has yet to come to full fruition, particularly in the U.S. As Dinesh Mohan states, “‘Road traffic injuries are the only public health problem for which society and decision-makers still accept death and disability among young people on a large scale. This human sacrifice is seen as a justifiable externality of doing business: the only discussion revolves around the number of deaths and injuries that are acceptable.”

We tend to emphasize the random, “accidental” nature of car crashes, something that would be unacceptable in the commercial aviation industry (which hasn’t had a fatality in the last two years). Protocols are set, rules are followed, training is essential, and pilots are encouraged to avoid overconfidence and respond to input from other staff. In his forthcoming book Why We Make Mistakes, Joseph T. Hallinan quotes a study showing when pilots and doctors were asked the question, “even when fatigued, I perform effectively during critical times,” 70% of doctors said yes, compared to only 26% of pilots (I’d like to see this question asked to drivers). Hallinan notes the human body is more complicated than aviation; but still, culture matters.

Driver overconfidence is, I think, a key factor, in the ongoing safety problem: I can drive tired or impaired; I can drive faster than everyone else; the crash is not me but every other driver. Drivers (like many doctors, according to Hallinan’s book) tend to get annoyed when they get “feedback” or input on their performance from their passengers. Unfortunately, drivers aren’t given the kind of training pilots are; but then again, it’s not performance as much as attitude that counts on the road (which is, as much as anything, a place of social interaction).

There are, of course, a number of ways safety culture has penetrated into driving. As James Hedlund writes, “Infant and toddler safety seat use is now an integral part of the whole country’s safety culture. Hospital policies require newborns to ride home in a child safety seat. NHTSA’s 2006 survey reported that 98% of infants under the age of one and 89% of toddlers age one to three were riding in child safety seats. There’s no indifference here: parents understand that they must properly secure their infants and toddlers in a scientifically-designed seat on each trip.”

But in so many other ways — speed, alcohol, mobile phones, etc. etc. — we toss safety culture out the window (even while the infant is strapped in). Just imagine the outcome yesterday if the pilot was fatigued, impaired, talking on the phone to his buddy in Reno, or just simply felt some rule or performance protocol didn’t apply to him. Yesterday may have been a miracle, but the outcome also represented the perfect alignment of a safety culture firing on all cylinders.

Posted on Friday, January 16th, 2009 at 10:27 am by: Tom Vanderbilt
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“A Dead Man Has No Right of Way”

That’s apparently a road warning sign in Lagos, Nigeria, from an interesting post on traffic, and other things.

We were a slave to our first real traffic jam today. It wasn’t so much that it took us three hours to get somewhere. It was more that there was a T intersection in a major road that was packed with cars, and our taxi driver was trying to make a left, across traffic, while everyone else seemed to be attempting a left in all 360 degrees. There was a small divider that was meant to guide people coming and going along where the base of the T met the top, one side to keep people coming, one side for those going. That’s what became the circle of traffic snarl. And there we sat for probably a half hour, millimetering our way into the smallest crevices between cars, as motorcycles squeezed through in all directions, street hawkers offered prepaid cellphone cards, candies, wallets, DVDs, whatever as they weaved their way between every car. Drivers began yelling at other drivers. Everyone looked kind of mad about the whole thing. As our car finally pointed in the direction of the turn, that was when I noticed that someone in an SUV had decided to drive against traffic along the wrong side of the base of T, which made it almost impossible, somehow, for anyone to pass a car in any direction. The pieces had all fit perfectly together, and no one could move. Had I not been paying attention in the moments up to this, and just had this single moment to draw information from, it would have been impossible for me to actually gauge which direction any car should have been going, based on a traffic pattern. This was what total chaos actually looks like. And just when it couldn’t get any more intense, police officers appeared from the other side of cars in front of us, yelling, waving big machine guns in the air, angry at the snarled traffic. One in particular was shouting “these drivers, look how they drive!” There was a moment when I had to remind myself that a lot of yelling goes on in places like Nigeria that doesn’t necessarily mean anything worse is around the corner. Like the two men yelling viciously at each other next to the car earlier that day, as we waited our way through another jam on the highway—you could just tell that, no matter how much they yelled, there weren’t going to be punches. In America, this would have looked like punches were coming. So, as the police were yelling and waving their guns, I had to take a deep breath and convince myself this was just like that earlier shouting match. No worries, right? Right?

Posted on Friday, January 16th, 2009 at 8:36 am by: Tom Vanderbilt
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Kazys Varnelis (via bldgblog) runs the stimulus numbers (his comments are in italics):

Modernize Roads, Bridges, Transit and Waterways: To build a 21st century economy, we must engage contractors across the nation to create jobs rebuilding our crumbling roads, and bridges, modernize public buildings, and put people to work cleaning our air, water and land.

· $30 billion for highway construction;

· $31 billion to modernize federal and other public infrastructure with investments that lead to long term energy cost savings;

· $19 billion for clean water, flood control, and environmental restoration investments;

· $10 billion for transit and rail to reduce traffic congestion and gas consumption.

Here is the meat of the proposals for infrastructure…and it’s pretty lean. $30 billion is less than one year’s expenditure on highways. $10 billion for transit and rail isn’t that much when just one crucial project, the Trans-Hudson Tunnel, is slated to cost $9 billion.

Reading the expanded version of the memo, things start to look positively grim.

· Upgrades and Repair: $2 billion to modernize existing transit systems, including renovations to stations, security systems, computers, equipment, structures, signals, and communications. Funds will be distributed through the existing formula. The repair backlog is nearly $50 billion.

· Amtrak and Intercity Passenger Rail Construction Grants: $1.1 billion to improve the speed and capacity of intercity passenger rail service. The Department of Transportation’s Inspector General estimates the North East Corridor alone has a backlog of over $10 billion.

· Airport Improvement Grants: $3 billion for airport improvement projects that will improve safety and reduce congestion. An estimated $41 billion in eligible airport infrastructure projects are needed between 2007-2011.

Posted on Thursday, January 15th, 2009 at 5:03 pm by: Tom Vanderbilt
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Smart Grids, Smart Roads

Last week Business Week was asking people, myself included, what advice they had for the new President vis a vis infrastructure and the stimulus package.

I said this:

“The Interstate Highway System was a marvel, but we don’t need another. By all means, fix the existing traffic infrastructure — roads, bridges, bottlenecks. But heedlessly laying more asphalt is a retrograde approach that rewards a counterproductive quest towards mobility for mobility’s sake. Instead of building new roads — which encourage unsustainable development patterns, more vehicular traffic, and are often only fully occupied at a few peak periods — we need to emphasize transit, but also smarter roads: Sensors that detect “non-recurring” traffic disruptions (the cause of an estimated one-third of traffic delays), intelligent traffic signals and variable speed limits and that react to changing conditions, systems that allow “hard shoulders” to be converted into extra traffic lanes, and real-time, occupancy-based tolling and parking programs.”

I was reminded of this when I read, in yesterday’s Wall Street Journal, an op-ed by IBM’s Samuel J. Palmisano.

He wrote: “Smarter infrastructure is by far our best path to creating new jobs and stimulating growth. We at IBM were asked to map this out by President-elect Barack Obama’s transition team, and our research shows that a $30 billion stimulus investment in just three areas — smart grids, health-care IT and broadband — could yield almost one million new jobs within one year. That’s possible because these kinds of infrastructure have significantly greater economic and societal multiplier effects than traditional infrastructure like bridges and highways.”

I was particularly interested in the next graph, and, as a thought experiment, try replacing the word ‘power’ with ‘travel’ (as in car travel):

“Our power grids are the largest remaining artifact of the Industrial Age, and they’re due for a smart upgrade. Using broadband data streams, digital sensors and advanced analytics, demand can be understood in real time. Utilities can source and manage power more intelligently, helping to bring renewable sources onto the grid. And consumers could understand the variable cost of power and alter their behavior accordingly. A smarter utility network could also handle the growing demand for hybrid and electric cars. Today’s utility grid would struggle to manage this burden.”

The idea of electric cars becoming part of a utility’s grid is an interesting one — in essence, then, congestion pricing would be the same thing as charging more when electrical usage surges. Of course, up to this point, most driving has been “too cheap to meter.” (or is that ramp-meter?)

Posted on Thursday, January 15th, 2009 at 4:50 pm by: Tom Vanderbilt
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“A Depraved Indifference to Human Life”

Required viewing for all drivers, via Streetsblog. I’m amazed at the way the defense attorney invokes Jeffrey Dahmer as the standard of a “murderer” — as if that crime somehow extends only to rampant, psychotic serial killers. Indeed, there is a risk in how drunk drivers are often portrayed, a subject I’ll return to in a later post: Presenting them as marginal social reprobates (and not, say, first-time offenders straight out of college) may encourage us to think that our own drinking and driving is something apart, something we can manage, something that would not end the same way.

Note that the presence of the DriveCam camera (a technology I describe in the book, though for its driver feedback properties) aided in the crash investigation.

Posted on Thursday, January 15th, 2009 at 1:56 pm by: Tom Vanderbilt
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Unhealthy Excuses

Via David Hembrow, I love these Dutch traffic education cards, each of which, as Hembrow translates, presents a reason kids might give to try to cadge a lift from their parents (and why they shouldn’t):

“1. The car is much quicker (by design in this country, cycling within town is generally quicker than driving).
2. My bag is much too heavy.
3. It’s too far (“Dad, do you know how far that walk is ? It’s 50000 centimetres!”)
4. It’s raining (“I just can’t wear this rain jacket”).”

Contrast this to the U.S., where many schools will not discharge a kid without a parent/driver there to pick them up.

Posted on Wednesday, January 14th, 2009 at 6:01 pm by: Tom Vanderbilt
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Get Yourself Seen

It’s a U.K. spot, circa 1976, but the singers sound very American, as funky but perhaps less psychedelic than the Kroft Supershow…

Posted on Wednesday, January 14th, 2009 at 5:45 pm by: Tom Vanderbilt
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The Enigma of Arrivals

Yesterday morning found me at a TRB panel, “Building the 21st Century Transportation System,” moderated by NYC’s own Janette Sadik-Khan. There were a number of interesting details offered — e.g., that J.S.K. had played rugby at Occidental College (she was abroad the year Barack Obama was there) a good skill set I think for navigating Gotham politics; or that Portlanders drive 4 fewer miles per day than other places in the U.S.; or that Seattle is high on the safety benefits of “advanced stop bars” — but one small anecdote that caught my attention in particular was offered by Fred Hansen, of Portland’s Tri-Met.

Talking about the city’s “Transit Tracker” program, which allows people to get real-time info on bus arrivals via their cell phones, Hansen mentioned a study that had been done in the U.K. of a similar program. What was noteworthy was that people using the service felt that the bus service itself had improved, that more buses were running, that they were running closer to schedule, even though none of this was empirically true.

I have a particular interest in the fluid nature of time, and the way travel, queuing, and even routing can play additive and subtractive games with this. Paco Underhill, for example, notes that people who wait in airport lines overestimate the time they waited by some 50 percent. I’ve also seen it noted that a train trip with a transfer feels longer to people than it really is, that people overestimate the time it will take to walk somewhere and underestimate the time it will take to drive somewhere. Of course, one of the masters of managing time is Disney, with its posted wait times (just posting the time makes it feel shorter for people) at queues, wait times which are then inflated — so the payoff at the end is even better: That wasn’t long at all!

The lesson here, I suppose, is that perception can be just as important as reality in crafting the “customer experience,” a lesson that applies as much to public transit as it does to the Magic Kingdom.

Posted on Wednesday, January 14th, 2009 at 5:00 pm by: Tom Vanderbilt
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Researcher Needed

Via John Adams:

“John Adams and (even older – positively venerable) Mayer Hillman are looking for a younger enthusiast to carry on a research project that Mayer and Anne Whalley began at the Policy Studies Institute. In 1971, they conducted a survey of English children’s independent mobility – how they got to school, visited friends and so on, whether they were allowed to get about and use public transport on their own and, if they owned a bicycle, to ride it on public roads, and how they spent the weekend previous to the survey. Parents also were involved by completing a questionnaire about the age up to which they imposed personal mobility restrictions on their children, and the reasons for doing so.

These surveys were repeated in the same schools in 1990 (published as One False Move … and available online at This follow-up study disclosed a dramatic loss of children’s independence over the previous 19 years. For instance, in 1971, 80% of 7 and 8-year old children got to school unaccompanied by an adult but by 1990 this proportion had fallen to 9%. With the collaboration of John Whitelegg, then at the Wuppertal Institute, matching surveys to provide a cultural comparison were conducted in West Germany. This revealed that, compared with the English, children there enjoyed a significantly higher level of independence.

Now, close on 20 years later, we think it would be instructive to conduct the surveys again to produce a 40-year review and to extend the comparison to other European countries to widen understanding of the influence of culture. The study would be an opportunity to chronicle the changes in children’s independent mobility and the possible relationship this has had with their physical and emotional development. It would also help to explain the social significance of children’s loss of what could be described as a right and enable lessons to be learned from wider international comparisons with the experience, behaviour and attitudes of children and parents in other countries…

…Anyone tempted, please contact Mayer in the first instance at”

Posted on Wednesday, January 14th, 2009 at 3:16 pm by: Tom Vanderbilt
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“I didn’t see any brake lights or emergency flashers”

July 15, 2008 -- An accident involving a tractor-trailer on Highway 40 west of Interstate 270 killed three people and injured 15.

The National Safety Council calls for a full ban on cell phones while driving, a position I in principle agree with (I’d rather it just became the norm rather than a law but sometimes the former requires the latter):

“There is a huge misperception with the public that it’s O.K. if they are using a hands-free phone,” said Janet Froetscher, the council’s president and chief executive. “It’s the same challenge we had with seat belts and drunk driving — we’ve got to get people thinking the same way about cellphones.”

And to give you a little nudge in that direction, here’s a piece from today’s St. Louis Post-Dispatch on a truck crash that killed three people:

“Authorities have only described Knight as being inattentive, but a Missouri Highway Patrol report has revealed he admitted to an investigator that he was distracted by a cell phone.

In the report, Knight is quoted as saying, “I reached across the dash to get my cell phone. I flipped the phone open, looked back at traffic, and I was there right at the last car (in the line of cars stuck in traffic). I didn’t see any brake lights or emergency flashers. After I hit the first car, I just remember holding the steering wheel and seeing cars going to my left and right.”

(thanks Jack!)

Posted on Tuesday, January 13th, 2009 at 2:42 pm by: Tom Vanderbilt
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The Frappuccino Effect

A librarian (the world would be a better place if there were more of them) waxes reflective on her hybrid car. Among other things, she notes:

Every car needs a MPG gauge. MPG gauges should be mandatory in vehicles. I think of this as the Frappuchino Effect, from the time my father called me to say he had learned that Frappuchinos had hundreds of calories. My dad has a bad heart, and to keep the load on his body light he’s watched his weight as long as I can remember. What seemed like a simple treat turned radioactive to him (and for that matter, to me). In the same vein, a MPG gauge in every car could get everyone driving smarter.

Posted on Tuesday, January 13th, 2009 at 7:03 am by: Tom Vanderbilt
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“Speed in and of itself is not reckless”

More Rumsfeldian parsings from the bizarre world of traffic law:

“Jockers said Danks was driving 59 mph in a 45-mph zone – or 14 mph over the speed limit – but speed alone is not sufficient to level a charge of vehicular homicide, he said. If Danks had been weaving through traffic or changing lanes before the collision, he might have been charged with a more serious offense, Jockers said.

Given that the chances that a pedestrian will live or die when struck by a car rises exponentially with speed, it seems strange to leave it out of the equation.

“His overall driving pattern did not rise to the level of recklessness, which is what you have to have to prove if you want to charge someone with vehicular homicide,” Jockers said. “Speed in and of itself is not reckless.”

Note the the “millionaire DWI killer,” in another case, was said to be going 60 mph in Manhattan. Good thing he didn’t change lanes — they would have thrown the book at him!

Posted on Monday, January 12th, 2009 at 6:11 am by: Tom Vanderbilt
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“Red Ink in the Rear-view Mirror”

There’s an obvious reason traffic fatalities have been dropping recently, in some cases to WW II levels: People can’t afford to do as much driving, or they’re paring back the ‘non-essential’ travel, or actually doing things like carpooling (and we should note that between 196 and 2001 the average number of annual miles traveled per American climbed some 180 percent). On the heels of a previous post, there may be another reason, as this St. Louis Post Dispatch piece notes:

“Thomas A. Garrett, an assistant vice president at the St. Louis Federal Reserve, knew he deserved to be ticketed while on vacation in Pennsylvania a few years ago. But, he wondered, are traffic tickets purely about public safety? Or are other factors at play? Many motorists probably have wondered the same thing sitting on a highway shoulder waiting for a citation. But Garrett turned it into a scholarly pursuit. He decided to conduct a study.

What Garrett and a co-author discovered provides yet another reason to hate a recession.

Traffic tickets go up significantly when local government revenue falls, they found. Their study showed for the first time evidence of how “local governments behave, in part, as though traffic tickets are a revenue tool to help offset periods of fiscal distress.”

No surprise, some ticketed motorists might say. But Garrett and co-author Gary A. Wagner, an economist at the University of Arkansas Little Rock, say they confirmed a connection that seemed to exist only in isolated anecdotes. And they put a number on it: Controlling for other factors, a 1 percentage point drop in local government revenue leads to a roughly .32 percentage point increase in the number of traffic tickets in the following year, a statistically significant connection.”

Posted on Monday, January 12th, 2009 at 5:56 am by: Tom Vanderbilt
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Malcolm Gladwell’s Favorite Reads

I’m delighted by the mention and in some good company here, via The Week:

Best books … chosen by Malcolm Gladwell

New Yorker contributor Malcolm Gladwell is the author of The Tipping Point and Blink. His newest work is the current best-seller Outliers: The Story of Success.

The Blind Side by Michael Lewis (Norton, $14). Lewis is the finest storyteller of our generation, and this is his best book. Supposedly about football (the title refers to the side of the field a quarterback is blind to), it’s actually an extraordinary story about love and redemption.

Should I Be Tested for Cancer? by H. Gilbert Welch (Univ. of Calif., $15). One of those gems to come out of the academic press failing to get the attention it deserves. It asks a seemingly nonsensical question: Are there situations when you shouldn’t be tested for cancer? And the answer is yes. If you’re worried about cancer, this lucidly argued book will be a godsend.

Freakonomics by Steven D. Levitt and Stephen J. Dubner (Morrow, $28). I don’t need to say much here. This book invented an entire genre. Economics was never supposed to be this entertaining.

Traffic by Tom Vanderbilt (Knopf, $25). One of the heirs to the Freakonomics legacy. A very clever young writer tells us all sorts of things about what driving says about us. I kept waiting for the moment when my interest in congestion and roads would run its course. It never did.

Nixon Agonistes by Garry Wills (Mariner, $15). A classic from the early ’70s by one of the great political writers of his time. Written just before Richard Nixon resigned, it’s as devastating a portrait of him as has ever been written.

The Opposable Mind by Roger Martin (Harvard Business School Press, $27). Explores what makes great CEOs stand out from their peers. I realize that there are thousands of business books on the subject, but, trust me, this is the first to really answer the question.

Posted on Sunday, January 11th, 2009 at 5:37 pm by: Tom Vanderbilt
Comments Off on Malcolm Gladwell’s Favorite Reads. Click here to leave a comment.

More Tickets, More Revenue, Fewer Crashes

It’s not uncommon to hear gripes of how traffic tickets, red light cameras, and the like are merely intended to boost revenues for cash-hungry towns. An interesting new paper from Michael D. Makowsky and Thomas Stratmann, looking at municipalities in Massachusetts (where the majority of tickets given by towns go to out-of-town drivers, particularly when towns are strapped, as indicated by their move to override the property tax cap) suggests that the revenue imperative in itself can help make the roads safer.

They write: “This paper shows that traffic fines reduce the number of car accidents and related injuries. We address the endogeneity problem that remains after using town and time effects by estimating the fixed effects model with instrumental variables. Our instrument is whether a town asked for more money through an override referendum and it’s interaction with stopped out of town drivers. Using panel data, we find that more tickets are issued when a town has asked for an override referendum, and that tickets issuance increase the more out of town drivers that are stopped, lending support to the tax exporting hypothesis while controlling for town fixed effects. Using these estimates, we find that tickets are a far more effective reducer of car accidents and automobile accident related injuries than ordinary least square estimation would indicate.”

Also of interest: “We find that in town with financial distress police officers are more likely to issue a ticket than a warning to out of town drivers.” (a finding that essentially jibes with what they concluded in another good paper, Makowsky, M. D. and T. Stratmann (2009). “Political Economy at Any Speed: What Determines Traffic Citations.” American Economic Review 99(1).

(via Marginal Revolution)

Posted on Friday, January 9th, 2009 at 1:10 pm by: Tom Vanderbilt
Comments Off on More Tickets, More Revenue, Fewer Crashes. Click here to leave a comment.
Traffic Tom Vanderbilt

How We Drive is the companion blog to Tom Vanderbilt’s New York Times bestselling book, Traffic: Why We Drive the Way We Do (and What It Says About Us), published by Alfred A. Knopf in the U.S. and Canada, Penguin in the U.K, and in languages other than English by a number of other fine publishers worldwide.

Please send tips, news, research papers, links, photos (bad road signs, outrageous bumper stickers, spectacularly awful acts of driving or parking or anything traffic-related), or ideas for my Transport column to me at:

For publicity inquiries, please contact Kate Runde at Vintage:

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For speaking engagement inquiries, please contact
Kim Thornton at the Random House Speakers Bureau:

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Traffic UK
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Upcoming Talks

April 9, 2008.
California Office of Traffic Safety Summit
San Francisco, CA.

May 19, 2009
University of Minnesota Center for Transportation Studies
Bloomington, MN

June 23, 2009
Driving Assessment 2009
Big Sky, Montana

June 26, 2009
PRI World Congress
Rotterdam, The Netherlands

June 27, 2009
Day of Architecture
Utrecht, The Netherlands

July 13, 2009
Association of Transportation Safety Information Professionals (ATSIP)
Phoenix, AZ.

August 12-14
Texas Department of Transportation “Save a Life Summit”
San Antonio, Texas

September 2, 2009
Governors Highway Safety Association Annual Meeting
Savannah, Georgia

September 11, 2009
Oregon Transportation Summit
Portland, Oregon

October 8
Honda R&D Americas
Raymond, Ohio

October 10-11
INFORMS Roundtable
San Diego, CA

October 21, 2009
California State University-San Bernardino, Leonard Transportation Center
San Bernardino, CA

November 5
Southern New England Planning Association Planning Conference
Uncasville, Connecticut

January 6
Texas Transportation Forum
Austin, TX

January 19
Yale University
(with Donald Shoup; details to come)

Monday, February 22
Yale University School of Architecture
Eero Saarinen Lecture

Friday, March 19
University of Delaware
Delaware Center for Transportation

April 5-7
University of Utah
Salt Lake City
McMurrin Lectureship

April 19
International Bridge, Tunnel and Turnpike Association (Organization Management Workshop)
Austin, Texas

Monday, April 26
Edmonton Traffic Safety Conference
Edmonton, Canada

Monday, June 7
Canadian Association of Road Safety Professionals
Niagara Falls, Ontario

Wednesday, July 6
Fondo de Prevención Vial
Bogotá, Colombia

Tuesday, August 31
Royal Automobile Club
Perth, Australia

Wednesday, September 1
Australasian Road Safety Conference
Canberra, Australia

Wednesday, September 22

Wisconsin Department of Transportation’s
Traffic Incident Management Enhancement Program
Statewide Conference
Wisconsin Dells, WI

Wednesday, October 20
Rutgers University
Center for Advanced Infrastructure and Transportation
Piscataway, NJ

Tuesday, March 8, 2011
Ontario Injury Prevention Resource Centre
Injury Prevention Forum

Monday, May 2
Idaho Public Driver Education Conference
Boise, Idaho

Tuesday, June 2, 2011
California Association of Cities
Costa Mesa, California

Sunday, August 21, 2011
American Association of Motor Vehicle Administrators
Milwaukee, Wisconsin

Wednesday, October 26, 2011
Attitudes: Iniciativa Social de Audi
Madrid, Spain

April 16, 2012
Institute for Sensible Transport Seminar
Gardens Theatre, QUT
Brisbane, Australia

April 17, 2012
Institute for Sensible Transport Seminar
Centennial Plaza, Sydney
Sydney, Australia

April 19, 2012
Institute for Sensible Transport Seminar
Melbourne Town Hall
Melbourne, Australia

January 30, 2013
University of Minnesota City Engineers Association Meeting
Minneapolis, MN

January 31, 2013
Metropolis and Mobile Life
School of Architecture, University of Toronto

February 22, 2013
ISL Engineering
Edmonton, Canada

March 1, 2013
Australian Road Summit
Melbourne, Australia

May 8, 2013
New York State Association of
Transportation Engineers
Rochester, NY

August 18, 2013 “Ingenuity” Conference
San Francisco, CA

September 26, 2013
TransComm 2013
(Meeting of American Association
of State Highway and Transportation
Officials’ Subcommittee on Transportation
Grand Rapids MI



January 2009

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