Navigating The Science (And Sociology) Of 'Traffic'

Rush hour in New York i i

hide captionMorning traffic is a perennial problem in New York.

Timothy A. Clary/Getty Images/AFP
Rush hour in New York

Morning traffic is a perennial problem in New York.

Timothy A. Clary/Getty Images/AFP

Unexpected Driving Tips from Traffic

  • The more congested a highway is, the less likely one is to save any time by switching to a faster lane.
  • Though it may seem rude, merging at the very point where a lane ends allows traffic to more rapidly.
  • In some cases, slowing down for a yellow light rather than speeding up may increase one's odds of getting into an accident.
Tom Vanderbilt

hide captionIn Traffic, Tom Vanderbilt writes that road rage does not necessarily have to be a bad thing — letting out one's frustrations in a semi-private space may actually be therapeutic, so long as it does not result in conflict with other drivers.

Kate Burton/Knopf

"How's my driving?" ask the backs of eighteen-wheelers. Writer Tom Vanderbilt thinks it could be better.

Vanderbilt's book Traffic: Why We Drive the Way We Do (and What It Says About Us) explores the sociology of driving — why roads are most congested on Saturdays, what percentage of traffic is drivers simply looking for parking, why new cars crash more often than old ones. The book is based on research and interviews with driving experts and traffic officials around the world.

Among Vanderbilt's findings is the discovery that "late merging" may actually cause traffic to move more quickly, contrary to popular belief. When a sign warns that the lane will end in a given distance, standard driving etiquette causes many to move over as promptly as possible. However, if everyone were to merge at a single point when the lane ends, the road would get maximal usage and lane changes would become more orderly. The result would be traffic that moves 15% faster than current behavior allows.

"If people were told exactly to not leave the lane that was closing until the very point it actually did close, and then we did a nice alternating merge — it would be faster," says Vanderbilt. "Another benefit would be the queue of vehicles stretching back from the construction site would be smaller."

Vanderbilt also argues that round-abouts may be safer than traditional stoplight intersections. Though traffic circles may seem confusing, they have fewer "conflict points," places where cars can physically hit an object or person. Intersections have 32 of these conflict points, where round-abouts only have 16. The round-about is particularly safe because it completely eliminates the left-turn, one of the most dangerous driving maneuvers.

Vanderbilt is a New-York based writer who covers topics such as design, technology, science, and culture for Wired, Slate, and The New York Times.

Excerpt: 'Traffic'

'Traffic'
Traffic: Why We Drive the Way We Do (and What It Says About Us)
By Tom Vanderbilt
Hardcover, 416 pages
Knopf
List Price: $24.95

Why I Became a Late Merger (and Why You Should Too)

Why does the other lane always seem to be moving faster?

It is a question you have no doubt asked yourself while crawling down some choked highway, watching with mounting frustration as the adjacent cars glide ahead. You drum the wheel with your fingers. You change the radio station. You fixate on one car as a benchmark of your own lack of progress. You try to figure out what that weird button next to the rearwindow defroster actually does.

I used to think this was just part of the natural randomness of the highway. Sometimes fate would steer me into the faster lane, sometimes it would relinquish me to the slow lane.

That was until recently, when I had an experience that made me rethink my traditionally passive outlook on the road, and upset the careful set of assumptions that had always guided my behavior in traffic.

I made a major lifestyle change. I became a late merger.

Chances are, at some point you have found yourself driving along the highway when a sign announces that the left lane, in which you are traveling, will close one mile ahead, and that you must merge right.

You notice an opening in the right lane and quickly move over. You breathe a sigh, happy to be safely ensconced in the Lane That Will Not End. Then, as the lane creeps to a slow halt, you notice with rising indignation that cars in the lane you have vacated are continuing to speed ahead, out of sight. You quietly seethe and contemplate returning to the much faster left lane–if only you could work an opening. You grimly accept your condition.

One day, not long ago, I had an epiphany on a New Jersey highway. I was having a typical white-knuckle drive among the scenic oil-storage depots and chemical-processing plants of northern Jersey when suddenly, on the approach to the Pulaski Skyway, the sign loomed: LANE ENDS ONE MILE. MERGE RIGHT.

Seized by some rash impulse, I avoided the instinctual tickle at the back of my brain telling me to get in the already crowded right lane. Just do what the sign says, that voice usually counsels. Instead, I listened to another, more insistent voice: Don't be a sucker. You can do better. I plowed purposefully ahead, oblivious to the hostile stares of other drivers. From the corner of my eye I could see my wife cringing. After passing dozens of cars, I made it to the bottleneck point, where, filled with newfound swagger, I took my rightful turn in the small alternating "zipper" merge that had formed. I merged, and it was clear asphalt ahead. My heart was beating faster. My wife covered her face with her hands.

In the days after, a creeping guilt and confusion took hold. Was I wrong to have done this? Or had I been doing it wrong all my life? Looking for an answer, I posted an anonymous inquiry on Ask MetaFilter, a Web site one can visit to ask random questions and tap into the "hive mind" of an anonymous audience of overeducated and overopinionated geeks. Why should one lane move faster than the other, I wanted to know, and why are people rewarded for merging at the last possible moment? And was my new lifestyle, that of the late merger, somehow deviant?

I was startled by the torrent of responses, and how quickly they came. What struck me most was the passion and conviction with which people argued their various cases–and the fact that while many people seemed to think I was wrong, almost as many seemed to think I was right. Rather than easy consensus, I had stumbled into a gaping divide of irreconcilable belief.

The first camp–let us name it after the bumper sticker that says practice random acts of kindness–viewed early mergers as virtuous souls doing the right thing and late mergers as arrogant louts. "Unfortunately, people suck," wrote one Random Acts poster. "They'll try whatever they can to pass you, to better enjoy the traffic jam from a few car lengths ahead of you. . . . People who feel that they have more pressing concerns and are generally more important than you will keep going, and some weak-spined schmuck will let them in further down, slowing your progress even more. This sucks; I'm afraid it's the way of the world."

Another camp, the minority camp-let's call them Live Free or Die, after the license-plate motto of the state of New Hampshire-argued that the late mergers were quite rationally utilizing the highway's maximum capacity, thus making life better for everyone. In their view, the other group's attempts toward politeness and fairness were actually detrimental to all.

It got more complicated. Some argued that late merges caused more accidents. Some said the system worked much better in Germany, and hinted that my dilemma perhaps revealed some national failing in the American character. Some said they were afraid of not being "let in" at the last moment; some said they would actively try to block someone from merging, the way truckers often do. So what was going on here? Are we not all driving the same road, did we not all pass the same driving tests? What was puzzling was not just the variety of responses but the sense of moral righteousness each person attributed to his or her highway behavior, and the vitriol each person reserved for those holding the opposite view. For the most part, people were not citing traffic laws or actual evidence but their own personal sense of what was right.

I even found someone claiming to have had a conversion experience exactly the opposite of mine. "Until very recently, I was a 'late merger,' " wrote the author, an executive with a software company, in a business magazine. Why had he become a born-again early merger? "Because I came to realize that traffic flowed faster the sooner people merged." He used this as a metaphor for successful team building in corporate America, in which "late mergers" were those who consistently put their own opinions and motives above the greater company. "Early mergers," he wrote, could help push companies to their "maximum communal speed." But did traffic flow faster when people merged sooner? Or did it just seem more noble to think that it did?

Excerpted from Traffic by Tom Vanderbilt Copyright © 2008 by Tom Vanderbilt. Excerpted by permission of Knopf, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

Books Featured In This Story

Traffic
Traffic

Why We Drive the Way We Do (and What It Says About Us)

by Tom Vanderbilt

Hardcover, 402 pages | purchase

close

Purchase Featured Books

  • Traffic
  • Why We Drive the Way We Do (and What It Says About Us)
  • Tom Vanderbilt

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and Terms of Use. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.

Support comes from: