Traffic Report

A new book on driving behavior looks at one of the banes of contemporary existence.

Tom Vanderbilt’s new book, Traffic: Why We Drive the Way We Do (and What It Says About Us) (Knopf), suffers from some unfortunate timing. As gas prices hit a string of record highs, and the disastrous environmental effects of carbon emissions are finally becoming a mainstream concern, along comes a book that promises to explain the traditional “mysteries of the road”: Why is the other lane always moving faster? How come Americans drive on the right side of the road while other countries drive on the left? Do women cause more traffic than men? Between the looming energy crisis and the bleak economy, you could be forgiven for finding these questions a bit frivolous. The nuances of driving behavior suddenly seem a lot less interesting when you can’t even afford to gas up your Honda.

Undoubtedly, the book seemed like a sure thing a few years ago, when publishers were hungry for Freakonomics-style analyses of every­day phenomena. It’s easy to imagine the calculus: Malcolm Gladwell plus Richard Florida plus traffic equal publishing gold! (Vanderbilt is an occasional contributor to Metropolis, and the high-six-figure book deal he scored in 2005 has taken on the tinge of office lore; it seemed to inspire the entire editorial staff to kick themselves for not thinking of the idea first.)

If those books are commonly lumped together as “pop psychology” or “pop economics,” you might say that Vanderbilt has pioneered the genre of “pop traffic engineering and urban planning.” And bad timing aside, he’s done a perfectly good job of it. Traffic is highly readable, and it will arm you for cocktail-party conversation for weeks. You may suddenly find yourself, for instance, a passionate and vocal supporter of higher-priced street parking. “In most cities, there is a glaring gap between the cost of a metered parking spot and that of an off-street parking garage,” Vanderbilt writes. “And so people are faced with a strong incentive to drive around looking for parking, rather than heading into the first available garage.” The result: more congestion and more crashes. Parking is responsible for almost one-fifth of all urban traffic collisions.

Similarly, you may start buttonholing strangers to tell them why you’re now a “late merger.” Picture this scenario: you are driving on the highway when a sign announces that the lane you’re traveling in will close one mile ahead—you must merge right. Many “early mergers” will conscientiously move over to the right lane at the first opportunity, only to find that some of their fellow drivers zoom along in the closing lane until the last possible second. Early mergers think they’re behaving virtuously and politely—and that late mergers are selfish jerks. (This was always my impression.) But the late mergers have their own case: they are rationally utilizing the highway’s maximum capacity. Merg­ing earlier than necessary needlessly restricts the available resources, making the drive slower for everyone. Become a late merger, Vanderbilt argues, and you will save time and make the system itself more efficient.

This is one of the rare examples in which the individual’s interest aligns with the greater good. More often the opposite is true. That’s why traffic engineers have such a hard job: they are dealing not just with networks of roads and intersections but with messy human psychology. For example, engineers have recently created systems that can track traffic flow through sensors buried in the road and provide nearly real-time data about congestion directly to dri­v­ers. This should help individuals and make the overall system more efficient, right? Wrong. When drivers see that a certain road is blocked, they will all flock to an alternate road, which will then become clogged. The forecast becomes, in the words of one professor, a “self-destroying prognosis.” To compensate, engineers have tried to predict people’s reactions and provide them with limited information that will, in theory, be the most beneficial for everyone—but it is a losing game. (Indeed, the system seems most effective when only a small elite is given access to the information, as happens in Hollywood each year with the many limo drivers shepherding stars to the Academy Awards.)

The best traffic engineers then are the ones with a subtle understanding of human behavior. Dutch engineer Hans Monderman is the most prominent example, and he becomes a sort of underdog protagonist of Vanderbilt’s book. Monderman, who died last January, invented what has been called “psychological traffic calming.” He successfully reduced speeding and crashes in Dutch villages by removing traffic signs and signals, which he felt insulated drivers from their immediate surroundings. Typically, drivers continued to speed even after they entered a village because they were still behaving by the impersonal rules of the highway. Make the driver feel like he is entering the social world of a village, Monderman argued, and he will intuitively slow down and watch for pedestrians, bicyclists, and other cars. (In an interview, Monderman demonstrated the safety of one of his sign-free villages by closing his eyes and walking backward through a busy road; the cars navigated around him without any honked horns or slammed brakes.)

It is fair to ask whether these experiments would ever fly in the United States. Certainly, other European-style measures have failed here. Congestion pricing is one of a few pragmatic solutions to gridlock that Vanderbilt offers, and he makes a convincing, if familiar, case for it. Busy roads should be treated as what they are—a scarce and limited resource—and priced accord­ingly. Doing so forces people to decide whether a given trip is worth it in monetary terms. And the money raised can be used to maintain our aging infrastructure and to fund public transportation.

The recent defeat of Mayor Michael Bloomberg’s congestion-pricing plan in New York—which would have charged $8 to cars and trucks entering the busiest part of Manhattan during peak hours—does not bode well for progressive solutions elsewhere in the country. Yet if politicians want to overcome the complexity of transportation problems, they will need to muster a lot more creativity and flexibility than they have thus far. They will need to look at the example of other countries with an open mind. They will need to think about infrastructure but also about human psychology. Traffic could be their textbook.

As for the rest of us, it is an engaging if not entirely satisfying read. Vanderbilt does everything right: he is a good writer and a thorough reporter; he consulted about 200 people and cites dozens of studies. (Indeed, the wealth of existing traffic literature is boggling.) As promised, Vanderbilt ex-plains the mysteries of driving behavior. Unfor­tunately, many of the answers make immediate intuitive sense; your mind refuses to get blown. Do women cause more traffic than men? Yes, because women still run more household errands than men do. Why are more pedestrians hit by cars in crosswalks than while jaywalking? Because jaywalkers are paying closer attention to traffic. Are dangerous roads safer than “safe” ones? Sometimes, because dangerous roads force us to drive carefully and not get lulled into complacency (or sleep). Would you be better off settling for the first available spot in a crowded parking lot rather than trolling the aisles for the closest one? Most assuredly, yes.

Mark Twain once wrote that “a nation is only an individual multiplied.” After reading Vanderbilt’s book, you might surmise that traffic is individuals’ worst instincts multiplied. He is certainly persuasive on one point: we are all worse drivers than we think we are. We gawk at roadside crashes, change lanes compulsively, fiddle with the radio, talk on the phone, daydream, get hypnotized by the road. Our perceptual equipment is inherently imperfect, and we are surprisingly bad at predicting the outcomes of our actions. No one, it seems, is ever wholly rational behind the wheel. But don’t fret: if oil reaches $200 a barrel, we will no longer have to worry about why the other lane is always moving faster. We’ll be taking the bus.

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