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

From the moment I heard about it, I couldn?t wait to get my hands on Tom Vanderbilt?s new book about traffic. I?m sure I wasn?t the only one. Haven?t we all pondered the mysteries of traffic endlessly (at least, it feels endless when you’re stuck in it)? After all, traffic is as pervasive as the common cold, except bigger, more relevant. Even the sickliest among us comes down with colds only intermittently.

And it?s not as if traffic jams are all that intuitive. Does it really make sense that if I slow down just a teeny, tiny bit to glance, ever so fleetingly, at the site of an accident in the other direction, a traffic jam is likely to ensue in my wake? My rubbernecking was so trifling — how could it possibly cause so much trouble? A book that explains this, and all the other seemingly insoluble questions that arise on the not-so-open road — one that would distill all the technical research and studies and god knows what else into prose one could get through — struck me, in the abstract, as sheer genius.

It turns out, however, that traffic is not all that interesting.

That said, Vanderbilt, a journalist, is an intelligent and wry writer, and he offers up some cocktail party-worthy nuggets of information. Who, for example, would have guessed that “late merging” is good for everyone? That is, what do you do when you see a sign that says the lane you are in will end in one mile? If you are like the old Vanderbilt, the pre-Traffic Vanderbilt, you “notice an opening in the right lane and quickly move over.” All is well until, “as the lane creeps to a slow halt, you notice with rising indignation that the cars in the lane you have vacated are continuing to speed ahead, out of sight.” The instinct of many people is to view those “late mergers” as “arrogant louts” who are cutting ahead in line, but it turns out they may be doing something right. This counterintuitive finding is explained to Vanderbilt this way: “The full capacity of the road is being used, rather than a bunch of people merging early and trying to create an artificial one-lane road earlier than necessary.” In Pennsylvania, where traffic engineers formally adopted the late-merge concept, traffic flow improved by 15 percent, Vanderbilt writes.

One is likely to come away from Traffic with an action plan. (In that, it?s like a self-help book.) It?s not just about vowing henceforth to merge late. Expect also to be newly committed to cautious driving in general — as well as convinced of the evil, evil, of talking on your cell phone while driving. Even the most hardened critics of the “nanny state” are likely to come away from this book ardent that something be done about such recklessness. “In 2006,” Vanderbilt tells us, “a Chicago driver reaching for a cell phone while driving lost control of his SUV, killing a passenger in another car?. The driver was fined $200.” That?s because the law typically treats anything except for driving under the influence of alcohol or drugs as an “accident,” no matter how egregious or irresponsible the behavior that led to it.

You may be wondering: what do the dangers of talking on one?s cell phone while driving have to do with traffic? It?s a good question, since the link is somewhat tenuous. Vanderbilt?s explanation is a bit schoolmarmish: “Rather than build more lanes, the best congestion solution?is for people to get in fewer crashes — which?would happen if drivers simply paid more attention to their driving,” Vanderbilt tells us. He?s surely right, but it seems a bit sneaky, something of a bait-and-switch. Who would have been eager to read a book about how to be a safer driver?

In fact, at least a third of the book is devoted not to traffic but to the danger inherent in driving. Incidentally, that?s not as boring as it sounds, in large part because Vanderbilt has some surprising things to say — reminders of our tendency to act irrationally (or at least in ways that confound experts). A “study in Finland?found that adding reflector posts to a curved road resulted in higher speeds and more accidents than when there were no posts,” he writes. “Other studies have found that drivers tend to go faster when a curve is marked with an advisory speed limit than when it is not.” As Vanderbilt spends a chapter explaining, this is largely because drivers are likely to “feel” safer with such things in place — and hence drive more dangerously.

As it turns out, there are a lot of things related to driving that are more interesting than the hows and whys of traffic jams — and Traffic discusses many of them, from free street parking (bad from a traffic perspective, as all the cars circling as they looking for parking jam the streets; besides, what a waste of valuable urban real estate — lending it out to cars for no fee!) to the relationship between driving culture and political norms (the more corrupt a society, the more harrowing its streets are likely to be — and that?s only partially because unqualified drivers pay bribes to get driver?s licenses).

But the very breadth of topics covered suggests the problem with Traffic the book, which ironically is similar to the problem with traffic the phenomenon. It is unpredictable; you never know what you will find when you go around the bend. The next section may be about ants (who commute very efficiently); or it may be about the way our driving behavior is influenced by feeling anonymous in our cars; or it may be about all the near-crashes we that we experience but barely notice, let alone learn from. There is no logical progression, no buildup to any unified theory.

Traffic is also repetitive. By book?s end, Vanderbilt sounds a little bit like the hectoring driver?s ed instructor — the one who makes it sound as if every time you drive to the market, you have a 50 percent chance of dying. (In fact, Vanderbilt tells us that over 50 years of driving, you have a 1-in-100 chance of dying in a car crash.) But how many times can we be told that we are irrational and drive recklessly?

As for the rubbernecking phenomenon that I was so eager to get to the bottom of, it turns out there?s not much to say. Vanderbilt dispatches with it in a single paragraph, writing “that when each driver slows to look at an accident for ten seconds, it does not seem egregious because they have already waited ten minutes. But that ten minutes arose from everybody else?s ten seconds.”

Somehow I expected the explanation to be more satisfying. But the fault is surely mine. It?s just traffic, after all.