Traffic: Why We Drive the Way We Do (and What It Says About Us) - Tom Vanderbilt (2008)

Chapter 1. Why Does the Other Lane Always Seem Faster? How Traffic Messes with Our Heads

Shut Up, I Can’t Hear You: Anonymity, Aggression, and the Problems of Communicating While Driving

HORN BROKEN. WATCH FOR FINGER.

—bumper sticker

In Motor Mania, a 1950 Walt Disney short, the lovably dim dog Goofy stars as “Mr. Walker,” a model pedestrian (on two legs). He is a “good citizen,” courteous and honest, the sort who whistles back at birds and wouldn’t “step on an ant.” Once Mr. Walker gets behind the steering wheel of his car, however, a “strange phenomenon takes place.” His “whole personality changes.” He becomes “Mr. Wheeler,” a power-obsessed “uncontrollable monster” who races other cars at stop lights and views the road as his own personal property (but still “considers himself a good driver”). Then he steps out of his car, and, deprived of his “personal armor,” reverts to being Mr. Walker. Every time he gets back into his car, despite the fact that he knows “how the other fellow feels,” he is consumed by the personality of Mr. Wheeler.

What Disney was identifying, in his brilliantly simple way, was a commonplace but peculiar fact of life: We are how we move. Like Goofy, I, too, suffer from this multiple personality disorder. When I walk, which as a New Yorker I often do, I view cars as loud, polluting annoyances driven by out-of-town drunks distracted by their cell phones. When I drive, I find that pedestrians are suddenly the menace, whacked-out iPod drones blithely meandering across the street without looking. When I ride a bike, I get the worst of both worlds, buffeted by speeding cars whose drivers resent my superior health and fuel economy, and hounded by oblivious pedestrians who seem to think it’s safe to cross against the light if “only a bike” is coming but are then startled and indignant as I whisk past at twenty-five miles per hour.

I am guessing this sort of thing happens to you as well. Let us call it a “modal bias.” Some of this has to do with our skewed perceptual senses, as I will discuss in Chapter 3. Some of it has to do with territoriality, like when bicyclists and pedestrians sharing a path yell at each other or someone pushing a triplet-sized stroller turns into the pedestrian version of the SUV, commandeering the sidewalk through sheer size. But something deeper and more transformative happens when we move from people who walk to people who drive. The “personal armor” described by Disney is perhaps not so far-fetched. One study of pedestrian fatalities by French researchers showed that a significant number were associated with a “change of mode”—for example, moving from car to foot—as if, the authors speculated, drivers leaving their vehicles still felt a certain invulnerability.

Psychologists have struggled to understand the “deviant driver,” creating detailed personality profiles to understand who’s likely to fall prey to “road rage.” An early mantra, originally applied to what was called the “accident-prone driver,” has long held sway: “A man drives as he lives.” This is why car insurance premiums are tied not only to driving history but, more controversially, to credit scores; risky credit, the thinking goes, correlates with taking risks on the road. The statistical association between lower credit scores and higher insurance losses is just that, however; the reasons why how one lives might be linked to how one drives are less clear. And as inquiries into this question typically involve questionnaires, they’re open to various self-reported response biases. How would you answer this sample question: Are you a raving psychopath on wheels? (Please check “never,” “sometimes,” or “always.”) Generally, these inquiries come to what hardly seem earth-shattering conclusions: that “sensation-seeking,” “risk-seeking,” “novelty-seeking,” and “aggressive” individuals tend to drive in a riskier, more aggressive manner. You weren’t going to bet your paycheck on daredevil drivers being the risk-averse people who crave quiet normalcy and routine, were you?

Even using a phrase like “road rage” lends a clinical legitimacy to what might simply be termed bad or boorish behavior elsewhere. “Traffic tantrums” is a useful alternative, nicely underscoring the raw childishness of aggressive driving. The more interesting question is not whether some of us are more prone to act like homicidal maniacs once we get behind the wheel but why we all act differently. What is going on seems to have less to do with a change in personality than with a change in our entire being. In traffic, we struggle to stay human.

Think of language, perhaps the defining human characteristic. Being in a car renders us mostly mute. Instead of complex vocabularies and subtle shifts in facial expression, the language of traffic is reduced—necessarily, for reasons of safety and economy—to a range of basic signals, formal and informal, that convey only the simplest of meanings. Studies have shown that many of these signals, particularly informal ones, are often misunderstood, especially by novice drivers. To take one example, the Reverend David Rowe, who heads a congregation in the wealthy Connecticut suburb of Fairfield and, improbably, is a great fan of the neopunk band Green Day, told me he was once driving down the road when he spotted a car with a Green Day bumper sticker. He honked to show his solidarity. For his efforts he was rewarded with a finger.

Even formal signals are sometimes hazy: Is that person who keeps driving with their right turn signal on actually going to turn or have they forgotten it’s still blinking? Unfortunately, there’s no way to ask the driver what they mean. This may lead to a rhetorical outburst: “Are you going to turn or not?” But you can’t ask; nor would there be a way to get an answer back. Frustrated by our inability to talk, we gesture violently or honk—a noise the offending driver might misinterpret. At some point you may have been the recipient of an unsolicited honk, to which you immediately responded with defensive anger—What?!—only to learn that the honker was trying to convey to you that you left your gas cap open. Thanks! Have a good one!

Traffic is riddled with such “asymmetries” in communication, as Jack Katz, a sociologist at the University of California in Los Angeles and the author of How Emotions Work, describes them. “You can see but you can’t be heard,” he told me. “In a very precise way, you’re made dumb. You can shout as much as you want but nobody’s going to hear you.”

Another way to think about this “asymmetry” is that while you can see a lot of other drivers making mistakes, you are less likely to see yourself doing so. (A former mayor of Bogotá, Colombia, had a wonderful solution to this, hiring mimes to people the city’s crosswalks and silently mock drivers and pedestrians who violated traffic laws.) Drivers also spend much of their time in traffic looking at the rear ends of other cars, an activity culturally associated with subordination. It also tends to make the communication one-way: You’re looking at a bunch of drivers who cannot see you. “It’s like trying to talk to someone who’s walking in front of you, as opposed to someone who’s face-to-face with you,” Katz says. “We’re looking at everybody’s rear, and that’s not how human beings were set up to maximize their communicative possibility.”

This muteness, Katz argues, makes us mad. We are desperate to say something. In one study, in-car researchers pretended to be measuring the speed and distance perception of drivers. What they were really interested in was how their subjects would react to a honk from another driver. They made this happen by giving subjects instructions as they paused at a stop sign. They then had an accomplice pull up behind the stalled car and honk. More than three-quarters of the drivers reacted verbally, despite the fact they would not be heard by the honker.

When a driver is cut off by another driver, the gesture is read as rude, perhaps hostile. There is no way for the offending driver to indicate that it was anything but rude or hostile. Because of the fleeting nature of traffic, the act is not likely to be witnessed by anyone else. No one, save perhaps your passenger, will shake their heads in unison with you and say, “Can you believe he did that?” There are at least two possible responses. One is to speed ahead and cut the offending driver off in turn, to “teach them a lesson.” But there is no guarantee that the person receiving the lesson is aware of what they have done—and so your lesson simply becomes a provocation—or that they will accept your position as the “teacher” in any case. And even if your lesson is successful, you’re not likely to receive any future benefit. Another response is to use an “informal” traffic signal, like the middle finger (or, as is gaining currency in Australia, the pinkie, after an ad campaign by the Road and Traffic Authority to suggest that the person speeding or otherwise driving aggressively is overcompensating for deficient male anatomy). This gains power, Katz says, if the person you give the finger to visually registers that you’re giving him the finger. But what if that person merely gives the finger back?

Finally, it is often impossible to even send a message to the offending driver in the first place. Yet still we get visibly mad, to an audience of no one. Katz argues that we are engaging in a kind of theatrical storytelling, inside of our cars, angrily “constructing moral dramas” in which we are the wronged victims—and the “avenging hero”—in some traffic epic of larger importance. It is not enough to think bad thoughts about the other driver; we get angry, in essence, to watch ourselves get angry. “The angry driver,” Katz argues, “becomes a magician taken in by his or her own magic.” Sometimes, says Katz, as part of this “moral drama,” and in an effort to create a “new meaning” for the encounter, we will try to find out something after the fact about the driver who wronged us (perhaps speeding up to see them), meanwhile running down a mental list of potential villains (e.g., women, men, teenagers, senior citizens, truck drivers, Democrats, Republicans, “idiots on cell phones,” or, if all else fails, simply “idiots”) before finding a suitable resolution to the drama.

This seems an on-road version of what psychologists call the “fundamental attribution error,” a commonly observed way in which we ascribe the actions of others to who they are; in what is known as the “actor-observer effect,” meanwhile, we attribute our own actions to how we were forced to act in specific situations. Chances are you have never looked at yourself in the rearview mirror and thought, “Stupid #$%&! driver.” Psychologists theorize that the actor-observer effect may stem from one’s desire to feel more in control of a complex situation, like driving in traffic. It also just might be easier to chastise a “stupid driver” for cutting you off than to fully analyze the circumstances that caused this event to occur.

On a larger scale, it might also help explain, more than actual national or civic chauvinism, why drivers the world around have their own favorite traffic targets: “The Albanians are terrible drivers,” say the Greeks. “The Dutch are the worst drivers,” say the Germans. It’s best not to get New Yorkers started about New Jersey drivers. We even seem to make the fundamental attribution error in the way we travel. When bicyclists violate a traffic law, research has showed it is because, in the eyes of drivers, they are reckless anarchists; drivers, meanwhile, are more likely to view the violation of a traffic law by another driver as somehow being required by the circumstances.

At least some of this anger seems intended to maintain our sense of identity, another human trait that is lost in traffic. The driver is reduced to a brand of vehicle (a rough stereotype at best) and an anonymous license-plate number. We look for glimpses of meaning in this sea of anonymity: Think of the curious joy you get when you see a car that matches your own, or a license plate from your home state or country when you are in another. (Studies with experimental games have shown that people will act more kindly toward someone they have been told shares their birth date.) Some drivers, especially in the United States, try in vain to establish their identities with personalized vanity plates, but this raises the question of whether you really want your life summed up in seven letters—let alone why you want to tell a bunch of people you don’t know who you are! Americans seem similarly (and particularly) predisposed to putting cheap bumper stickers on their expensive cars—announcing the academic wizardry of their progeny, jocularly advising that their “other car is a Porsche,” or giving subtle hints (“MV”) of their exclusive vacation haunts. One never sees a German blazing down the autobahn with a PROUD TO BE GERMAN sticker.

Trying to assert one’s identity in traffic is always going to be problematic, in any case, because the driver yields his or her identity to the cars. We become, Katz says, cyborgs. Our vehicle becomes our self. “You project your body way out in front of a vehicle,” says Katz. “When somebody’s changed lanes a hundred yards ahead, you instantly feel you’ve been cut off. They haven’t touched you physically, they haven’t touched your car physically, but in order to adjust the wheel and acceleration and braking, you have projected yourself.” We say, “Get out of my way,” not “Get out of my and my car’s way.”

Identity issues seem to trouble the driver alone. Have you ever noticed how passengers rarely seem to get as worked up about these events as you do? Or that they may, in the dreaded case of the “backseat driver,” even question your part in the dispute? This may be because the passenger has a more neutral view. They do not feel that their identity is bound up with the car. Studies that have examined the brain activity of drivers and passengers as they engaged in simulated driving have shown that different neural regions are activated in drivers and passengers. They are, in effect, different people. Studies have also shown that solo drivers drive more aggressively, as measured by such indices as speed and following distance. It is as if, lacking that human accompaniment—and thus any sense of shame—they give themselves over to the car.

Like many everyday travails, this whole situation is succinctly illustrated in a hit country song, Chely Wright’s “The Bumper of My S.U.V.” The song’s protagonist complains that a “lady in a minivan” has given her the finger because of a United States Marines Corps bumper sticker on her SUV. “Does she think she knows what I stand for / Or the things that I believe,” sings Wright, “just because the narrarator has a bumper sticker for the U.S. Marines on the aforementioned bumper of her S.U.V.?” The first issue here is the struggle over identity; the narrator is upset that her identity has been defined by someone else. But the narrator may be protesting too much: How else would we know the things that you stand for or believe if you did not have a bumper sticker on your SUV? And if you are resentful at having your identity pigeonholed, why put a pigeonholing sticker on your bumper in the first place?

In the absence of any other visible human traits, we do draw a lot of information from bumper stickers. This point was demonstrated by an experiment conducted in 1969 at California State College, a place marked by violent clashes between the Black Panther Party and the police. In the trial, fifteen subjects of varying appearance and type of car affixed a bright BLACK PANTHER sticker to their auto’s rear bumper. No one in the group had received traffic violations in the past year. After two weeks with the bumper sticker, the group had been given thirty-three citations. (The idea that people with distinguishing marks on their vehicle will be singled out for abuse or cause other disruptions of smooth traffic is just one of the problems with proposals to add scarlet letter–style designations to license plates; suggestions have ranged from identifying sex offenders in Ohio to marking the cars of the reckless drivers known as “hoons” in Australia.)

In being offended, the SUV driver has made several huge assumptions of her own. First, she has presumed that the finger had something to do with the bumper sticker, when in fact it could have been directed at a perceived act of aggressive driving on her part. Or could it have been the fact that this single driver was tooling around in a large SUV, inordinately harming the environment, putting pedestrians and drivers of cars at greater risk, and increasing the country’s dependence on foreign oil? Secondly, by invoking a “lady in a minivan,” later echoed by references to “private schools,” she is perpetuating a preemptive negative stereotype against minivans: that their drivers are somehow more elitist than the drivers of SUVs—which makes no sense as SUVs, on average, cost more than minivans. The narrator is guilty of the same thing she accuses the minivan driver of.

In traffic, first impressions are usually the only impressions. Unlike the bar in Cheers, traffic is a place where no one knows your name. Anonymity in traffic acts as a powerful drug, with several curious side effects. On the one hand, because we feel that no one is watching, or that no one we know will see us, the inside of the car itself becomes a useful place for self-expression. This may explain why surveys have shown that most people, given the choice, desire a minimum commute of at least twenty minutes. Drivers desire this solitary “me time”—to sing, to feel like a teenager again, to be temporarily free from the constricted roles of work and home. One study found that the car was a favored place for people to cry about something (“grieving while driving”). Then there’s the “nose-pick factor,” a term used by researchers who install cameras inside of cars to study drivers. They report that after only a short time, drivers will “forget the camera” and begin to do all sorts of things, including nasal probing.

The flip side of anonymity, as the classic situationist psychological studies of Philip Zimbardo and Stanley Milgram have shown, is that it encourages aggression. In a well-known 1969 study, Zimbardo found that hooded subjects were willing to administer twice the level of electric shock to others than those not wearing hoods. Similarly, this is why hooded hostages are more likely to be killed than those without hoods, and why firing-squad victims are blindfolded or faced backward—not for their sake, but to make them look less human to the executioners. Take away human identity and human contact and we act inhuman. When the situation changes, we change.

This is not so different in traffic. Instead of a hood, we have the climate-controlled enclosure of the car. Why not cut that driver off? You do not know them and will likely never see them again. Why not speed through this neighborhood? You don’t live here. In one study, researchers planted a car at an intersection ahead of a series of various convertibles, and had the blocking car intentionally not move after the light changed to green. They then measured how quickly the driver behind the plant vehicle honked, how many times they honked, and how long each honk was. Drivers with the top down took longer to honk, honked fewer times, and honked for shorter durations than did the more anonymous drivers with the tops up. It could have been that the people who put their tops down were in a better mood to begin with, but the results suggest that anonymity increases aggressiveness.

Being in traffic is like being in an online chat room under a pseudonym. Freed from our own identity and surrounded by others known only by their “screen names” (in traffic, license plates), the chat room becomes a place where the normal constraints of life are left behind. Psychologists have called this the “online disinhibition effect.” As with being inside the car, we may feel that, cloaked in electronic anonymity, we can at last be ourselves. The playing field has been leveled, all are equal, and the individual swells with exaggerated self-importance. As long as we’re not doing anything illegal, all is fair game. This also means, unfortunately, that there is little incentive to engage in normal social pleasantries. And so the language is harsh, rude, and abbreviated. One faces no consequences for one’s speech: Chat room visitors aren’t speaking face-to-face, and do not even have to linger after making a negative comment. They can “flame” someone and sign off. Or give someone the finger and leave them behind a cloud of exhaust.

Are You Lookin’ at Me? Eye Contact, Stereotypes, and Social Interaction on the Road

GEORGE: This guy’s giving me the stare-ahead.

JERRY: The stare-ahead. I hate that. I use it all the time.

GEORGE: Look at me! I am man! I am you!

Seinfeld

The movie Crash opens with the voice of the narrator, a driver in Los Angeles, speaking over a scene of a collision. “In L.A., nobody touches you. We’re always behind this metal and glass. I think we miss that touch so much that we crash into each other, just so we can feel something.” The statement is absurd, but not without truth. Sometimes, we do come across little moments of humanity in traffic, and the effect is powerful. A classic case you have no doubt experienced is when you are trying to change lanes. You catch someone’s eye, they let you in, and you wave back, flushed with human warmth. Now, why did that feel so special? Is it just because traffic life is usually so anonymous, or is something else going on?

Jay Phelan, an evolutionary biologist who works a few buildings over from Jack Katz at UCLA, often thinks about traffic as he pilots his motorcycle through Los Angeles. “We evolved in a world in which there were about a hundred people in the group you were in,” he says. “Every person you saw you had an ongoing relationship with.” Was that person good to you? Did they return the spear they borrowed last week? This way of getting along is called “reciprocal altruism.” You scratch my back, I’ll scratch yours; we each do it because we think it will benefit us “down the road.” What happens in traffic, Phelan explains, is that even though we may be driving around Los Angeles with hundreds of thousands of anonymous others, in our ancient brains we are Fred Flintstones (albeit not driving with our feet), still inhabiting our little prehistoric village. “So when someone does something nice for you on the road, you’re processing it like, ‘Wow, I’ve got an ally now.’ The brain encodes it as the beginning of a long-term reciprocal relationship.”

When someone does something good or something bad, Phelan suggests, we keep score in our heads—even though the chances are infinitely small that we will ever see that person again. But our big brains, which are said to have evolved to help manage relatively large social networks, might be getting a powerful signal from that encounter. So we get angrier than we really should over minor traffic slights, or feel much better than we should after moments of politeness. “I feel like that happens a lot on the road,” says Phelan. “Somebody waves you over to get in the turn lane. I get these unjustified warm feelings about the world, that there’s kindness in it and everybody’s looking out for each other.” Or someone cuts you off, and the world is a dark, nasty place. In theory, neither should matter all that much, but we seem to react strongly either way.

These moments seem like traffic versions of the “ultimatum game,” an experiment used by social scientists that seems to reveal an inherent desire for reciprocal fairness in humans. In the game, one person is given a sum of money and an instruction to share it with another person as they see fit. If the second person accepts the offer, both keep their share; if he or she rejects it, neither gets anything. Researchers have found that people will routinely reject offers that are less than 50 percent, even though this means they walk away with nothing. The cost is less important than the sense of fairness, or perhaps the bad feeling of being on the “losing end.” (One study showed that people who did more rejecting had higher testosterone levels, which probably also explains why I tend to get more worked up about people who cut me off than my wife does.)

This sense of fairness might cause us to do things in traffic like aggressively tailgate someone who has done the same to us. We do this despite the costs to our own safety (we might crash, they might be homicidal) and the fact that we will never see the person we are punishing again. In small towns, it makes sense to be polite in traffic: You might actually see the person again. They might be related to you. They might learn not to do that to you again. But on the highway or in large cities, it is a puzzle why drivers try to help or hurt each other; those other drivers are not related to you (or even an immediate threat to your “kinship group”), and you are not likely to ever see those other drivers again. Have we been fooled into thinking our altruistic gesture might be returned, or are we just inherently nice? This traffic behavior is simply one part of the larger puzzle of why humans—who, unlike ants, are not all brothers and sisters working for the queen—get along (give or take your occasional war), something that scientists are still working to explain.

The Swiss economist Ernst Fehr and his colleagues have proposed a theory of “strong reciprocity,” which they define as “a willingness to sacrifice resources for rewarding fair and punishing unfair behavior even if this is costly and provides neither present nor future material rewards for the reciprocator.” This is, after all, what we are doing when we go out of our way to scold someone on the road. In experimental games that involve people donating money into a communal investment pot, the best outcome for all players is achieved when everyone pools their resources. But a single player can do best if they contribute nothing, skimming off everyone else’s profits instead. (This is like the person who drives to the front of a lengthy queue waiting to exit the highway and jumps in at the last minute.) Gradually, players stop contributing to the pool. Cooperation breaks down. When players in Fehr’s game are given an option to punish people for not investing, however, after a couple of rounds most people give everything they have. The willingness to punish seems to ensure cooperation.

So perhaps, as the economist Herbert Gintis suggests, certain forms of supposed “road rage” are good things. Honking at or even aggressively tailgating that person who cut you off, while not strictly in your best self-interest, is a positive for the species. “Strong reciprocators” send signals that may make would-be cheaters more likely to cooperate; in traffic, as with any evolutionary system, conforming to the rules boosts the “collective advantage” of the group, and thus helps the individual. Not doing anything raises the risk that the transgressor will harm the good-driving group. You were not thinking of the good of the species when you honked at a rude driver, you were merely angry, but your anger may have been altruistic all the same. (And, like a bird squawking to warn of an approaching predator, honking at a threatening driver does not consume much energy.) In other words: Honk if you love Darwin!

Whatever the evolutionary or cultural reasons for cooperation, the eyes are one of its most important mechanisms, and eye contact may be the most powerful human force we lose in traffic. It is, arguably, the reason why humans, normally a quite cooperative species in comparison with our closest primate relatives, can become so noncooperative on the road. Most of the time we are moving too fast—we begin to lose the ability to maintain eye contact around 20 miles per hour—or it is not safe to look. Maybe our view is obstructed. Often other drivers are wearing sunglasses, or their car may have tinted windows. (And do you really want to make eye contact with those drivers?) Sometimes we make eye contact through the rearview mirror, but it feels weak, not quite believable at first, as it is not “face-to-face.”

Because eye contact is so absent in traffic, it can feel uncomfortable when it does happen. Have you ever been stopped at a light and “felt” someone in a neighboring car looking at you? It probably made you uneasy. The first reason for this is that it may violate the sense of privacy we feel in traffic. The second is that there is no purpose for it and no appropriate neutral reaction, a condition that can provoke a fight-or-flight response. So what did you do at the intersection when you saw someone looking at you? If you sped up, you were not alone. In one study, researchers had an accomplice drive up on a scooter next to cars waiting at a traffic signal and stare at the driver of a neighboring car. These drivers roared through the intersection faster than those who were not stared at. Another study had a pedestrian stare at a driver waiting at the light. The result was the same. This is why trying to make eyes at your neighboring driver is bound to fail, and it is the larger problem with in-car dating networks like Flirting in Traffic, which allow drivers to send messages (via an anonymous e-mail to a MySpace-style Web site) to people bearing a special sticker. Most people—except middle-aged guys in Ferraris—do not want to be stared at while driving.

When you need to do something like change lanes, however, eye contact is a key traffic signal. On television’s Seinfeld, Jerry Seinfeld was on to something when he advised George Costanza, who was waving his hand while trying to negotiate a difficult New York City merge, “I think we’re gonna need more than a hand. They have to see a human face.”

Many studies have confirmed this: Eye contact greatly increases the chances of gaining cooperation in various experimental games (it worked for Seinfeld’s George, by the way). Curiously, the eyes do not even need to be real.One study showed that the presence of cartoon eyes on a computer screen made people give more money to another unseen player than when the eyes were not present. In another study, researchers put photographs of eyes above an “honor system” coffee machine in a university break room. The next week, they replaced it with a photograph of flowers. This cycle was repeated for a number of weeks. Consistently, more people made donations on “eye” weeks. The very design of our eyes, which contain more visible sclera, or “white,” than those of any of our closest primate relatives, may have even evolved, it has been argued, to facilitate cooperation in humans. This greater proportion of white helps us “catch someone’s eye,” and we’re particularly sensitive to the direction of one’s gaze. Infants will eagerly follow your glance upward but are less likely to follow if you close your eyes and simply tilt your head up. The eyes, one might argue, help reveal what we would like; eye contact is also a tacit admission that we do not think we will be harmed or exploited if we disclose our intentions.

There are times when we do not want to signal our intentions. This is why some poker players wear sunglasses. It also helps explain another game: driving in Mexico City. The ferocity of Mexico City traffic is revealed by the topes, or speed bumps, that are scattered throughout the capital like the mysterious earthen mounds of an ancient civilization. Mexico City’s speed bumps may be the largest in the world, and in their sheer size they are bluntly effective at curbing the worst impulses of chilango (as the capital’s residents are known) motorists. Woe to the driver who hits one at anything but the most glacial creep. Older cars have been known to stall out at a bump’s crest and be turned into a roadside food stand.

Topes are hardly the only traffic hazard in Mexico City. There are the secuestros express, or “express kidnappings,” in which, typically, a driver stopped at a light will be taken, at gunpoint, to an ATM and forced to withdraw cash. Often the would-be criminal is more nervous than the victim, says Mario González Román, a former security official with the U.S. embassy and himself a kidnapping victim. Calmness is essential. “Most of the people dead in carjackings are people that send the wrong signal to the criminal,” he explained while driving the streets of the capital in his 1976 Volkswagen Beetle (known as a vocho). “You have to facilitate the work of the criminal. If the car is all he wants, you are lucky.”

Express kidnappings, thankfully, are fairly rare in Mexico City. The more common bane of driving in the Distrito Federal is the endless number of intersections without traffic lights. Who will go, who will yield—it is an intricate social ballet with rough, vague guidelines. “There is no order, it’s whoever arrives first,” according to Agustín Barrios Gómez, an entrepreneur and sometime politico, as he drove in the Polanco neighborhood in his battered Nissan Tsuru, a car that seemed a bit beneath his station. “Mexican criminals are very car-conscious and watch-conscious,” he explained. “In Monterrey I wear a Rolex; here I wear a Swatch.” At each crossing, he slowed briefly to assess what the driver coming from the left or right might be doing. The problem was that cars often seemed to be arriving at the same time. In one of these instances, he barreled through, forcing a BMW to stop. “I did not make eye contact,” he said firmly, after clearing the intersection.

Eye contact is a critical factor at unmarked intersections in Mexico City. Look at another driver and he will know that you have seen him, and thus dart ahead of you. Not looking at a driver shifts the burden of responsibility to him (assuming he has actually seen you), which allows you to proceed first—if, that is, he truly believes you are not aware of him. There’s always the chance that both drivers are not actually looking. In the case of Barrios Gómez, the perceived social cost of stopping might have been greater for the BMW, higher as it is in the social hierarchy than an old Nissan Tsuru; then again, the BMW had more to lose in terms of sheer car value by not stopping. Drivers not wanting to cooperate, unwilling to begin that relationship of “reciprocal altruism,” simply do not look, or they pretend not to look—the dreaded “stare-ahead.” It is the same with the many beggars found at intersections in Mexico City. It is easier not to give if one does not make eye contact, which is why one sees, as in other cities, so many drivers looking rigidly ahead as they wait for the light.

Your daily drive may not seem to have much to do with the strategies of the Cold War, but every time two cars approach an unmarked intersection simultaneously, or four cars sidle up to a four-way stop at about the same time, a form of game theory is being applied. Game theory, as defined by the Nobel Prize–winning economist Thomas Schelling, is the process of strategic decision making that occurs when, as in a nuclear standoff or a stop-sign showdown, “two or more individuals have choices to make, preferences regarding the outcomes, and some knowledge of the choices available to each other and of each other’s preferences. The outcome depends on the choices that both of them make, or all of them if there are more than two.”

Traffic is filled with these daily moments of impromptu decision making and brinksmanship. As Schelling has argued, one of the most effective, albeit risky, strategies in game theory involves the use of an “asymmetry in communication.” One driver, like Barrios Gómez in Mexico City, makes himself “unavailable” to receive messages, and thus cannot be swayed from going first through the intersection. These sorts of tactics can be quite effective, if you feel like risking your neck to prove a bit of Cold War strategy. Pedestrians, for example, are told that making eye contact is essential to crossing the street at a marked crosswalk (the kind without traffic lights), but at least one study has shown that drivers were more likely to let pedestrians cross when they did not look at the oncoming car.

Drivers at intersections are acting from a complicated set of motives and assumptions that may or may not have anything to do with traffic law. In one study, researchers showed subjects a series of photographs of an intersection toward which two vehicles, equally distant from the intersection, were traveling. One had the legal right-of-way, and the other did not; the second driver also did not know if the first driver would take the right-of-way. Subjects were asked to imagine that they were one of the drivers and to predict who would “win” the right-of-way under a variety of conditions; whether they were making eye contact, whether they were a man or a woman, and whether they were driving a truck, a medium-sized car, or a small car. Eye contact mattered hugely. When it was made, most subjects thought the driver who had the legal right-of-way would claim it. Drivers were also more likely to yield when the approaching car was the same size. They were even more likely to yield when the driver was female—an artifact, the researchers suggested, of a belief that women drivers were less “experienced,” “competent,” or “rational.” Or was it just chivalry?

Traffic is thus a living laboratory of human interaction, a place thriving with subtle displays of implied power. When a light turns green at an intersection, for example, and the car ahead of another driver has not moved, there is some chance that a horn will be sounded. But when that horn will be sounded, for how long and how many times it will be sounded, who will be sounding the horn, and who the horn will be sounded at are not entirely random variables.

These honks follow observed patterns that may or may not fit your preexisting notions. We’ve already seen that drivers in convertibles with their tops down, less cloaked in anonymity, were less likely to honk than other drivers. For a similar reason, drivers in New York City, surrounded by millions of strangers, are likely to honk more, and sooner, than a driver in a small town in Idaho, where a car that has not moved might not be a random nuisance but the stalled vehicle of a friend. What the driver ahead is doing also matters. One study showed that when a car was purposely held as the light changed to green, drivers were more likely to honk—more often and for a longer time—if the nonmoving driver was quite obviously having a cell phone conversation than if they were not. (Men, it turned out, were more likely to honk than women, though women were just as likely to visibly express anger.)

All kinds of other factors—everything from gender to class to driving experience—also come into play. In another classic American study, replicated in Australia, the status of the car that did not move was the key determinant. When the “blocking car” was “high-status,” the following drivers were less likely to honk than when a cheaper, older car was doing the blocking. A study in Munich reversed the equation, keeping the car doing the blocking the same (a Volkswagen Jetta) and looking instead at who did the honking; if you guessed Mercedes drivers were faster to the horn than Trabant drivers, you guessed right. A similar study tried in Switzerland did not find this effect, which suggests that cultural differences, like the Swiss reserve and love of quiet, may have been at work. Another study found that when the driver of the blocking car was a woman, more drivers—including women—would honk than when it was a man. An experiment in Japan found that when the blocking drivers drove cars with mandatory “novice driver” stickers, the cars behind were more likely to honk than when they did not (perhaps the horn was just a driving “lesson”). A study across several European countries found that drivers were more likely to honk, and honk sooner, when the stalled driver ahead had an identity sticker indicating that they were from another country than when they were fellow nationals.

Men honk more than women (and men and women honk more at women), people in cities honk more than people in small towns, people are more reluctant to honk at drivers in “nice” cars—perhaps you already suspected these things. The point is that as we are moving around in traffic, we are all guided by a set of strategies and beliefs, many of which we may not even recognize as we act upon them. This is one of the themes guiding a fascinating series of experiments by Ian Walker, a psychologist at the University of Bath in England. In a complex system such as traffic, Walker says, where myriad people with a loose sense of the proper traffic code are constantly interacting, people construct “mental models” to help guide them. “They just develop their own idea of how it works,” Walker told me over lunch in the village of Salisbury. “And everyone’s got different ideas.”

Take the case of a car and a bicycle at an intersection. As it happens, studies consistently show intersections to be one of the most dangerous places for cyclists (not to mention cars) in traffic. Some of the reasons have to do with visibility and other perceptual problems; these will be addressed in Chapter 3. But even when drivers do see cyclists, things are not so simple. In one study, Walker showed “drivers” (i.e., qualified drivers in a lab) a photograph of a cyclist stopped at an intersection who was gazing toward the cross street but not making a turn signal with their arm. When drivers were asked to predict the cyclist’s next move, 55 percent said the cyclist was not going to turn, but 45 percent said the opposite. “This is what I mean about the informality of people’s mental models,” he said. “There are a lot of informal signals on the road that are being used. In that study you’ve actually got half the population taking it to mean one thing and half the population taking it to mean another thing—which is crying out for accidents.”

But there’s something even more interesting than mere misinterpretation going on here, Walker suggests. In another study, Walker presented subjects (again, qualified drivers in a lab) with photographs of a brightly clad bicyclist in a number of different traffic situations in a typical English village. Using a computer, the subjects were asked to “stop” or “go” depending on what they thought the cyclist was going to do at various intersections. Cyclists were shown making a proper turn signal with the arm, giving a glance or a look over the shoulder, or not signaling at all. Results were tallied on the number of “good outcomes” (when the driver made the right choice), “false alarms” (the driver stopped when they did not have to), and what Walker predicted would be collisions. As might be expected (or hoped), drivers tended to sound false alarms most often when a cyclist looked over their shoulder or gave no signal at all. As they did not know what the cyclist was going to do, they behaved over-cautiously. But when Walker studied the “collisions,” he found that these happened most often when the cyclist had given the most clear indication of all, an arm turning signal. What’s more, when drivers made the correct decision to stop, their reaction times were slowest when they were confronted with the arm signal.

Why should proper signaling, even when it’s seen and understood by the driver, be more linked to danger in this study than lack of signaling? The answer may be that the cyclists are guilty of simply looking like humans, rather than anonymous cars. In a previous study, Walker had subjects look at various photographs of traffic and describe what was going on. When subjects saw a photograph with a car, they were more likely to refer to the photo’s subject as a thing. When subjects looked at a picture that showed a pedestrian or a cyclist, they were more likely to use language that described a person. It somehow seems natural to say “the bicyclist yielded to the car,” while it sounds strange to say “the driver hit the bicycle.” In one photograph Walker showed, a woman was visible in a car, while a man on a bike waited behind. Although the woman could be clearly seen in the car, she was never referred to as a person, while the cyclist almost always was. Even when she was visible she was rendered invisible by the car.

In theory, this is good news for bicycle riders: What cyclist does not want to be considered human? The problem may come from the inhuman environment of traffic I have already described. Vehicles are moving at velocities for which we have no evolutionary training—for most of the life of the species we did not try to make interpersonal decisions at speed. So, when we’re driving and along comes a person on wheels, we cannot help but look at their face and, again, their eyes. In another study Walker performed, using photographs of cyclists and subjects hooked up to eye-tracking software, he found that the subjects’ gazes went instinctively toward the cyclists’ faces and lingered there longest, no matter what other information was in the picture.

Eyes are the original traffic signals. Walker has a good demonstration of this. On his laptop are two photographs of himself. In one, he is looking straight at the camera (i.e., the viewer). In another, he’s looking almost imperceptibly askance, but I could still feel, quite powerfully, that something had changed. How much had his eyes moved so that I knew he was no longer looking at me? A mere two pixels (out of 640 pixels across the width of the screen). What Walker is suggesting is that when we view a cyclist’s eyes, or even their arm motion, we begin—perhaps automatically—a chain of cognitive processing. We cannot help but look for those things we seek out when we see another person. This seems to take longer than looking at mere things, and it seems to involve more mental effort (studies have shown that electroencephalographic, or EEG, readings spike when two people’s eyes meet). We may be trying to gauge more from them than simply which direction they are going to turn. We may be looking for signs of hostility or kindness. We may be looking for reciprocal altruism. We may look where they are looking rather than see what their arm is signaling.

Whether or not we realize it, we are always making subtle adjustments in traffic. A kind of nonverbal communication is going on. Walker revealed this in a powerful way when he moved from the lab setting to the actual road. As a cyclist himself, he was curious about the anecdotal accounts from cyclists who said, in effect, that the more road space they took up, the more space passing cars gave them. He was also curious about survey reports that hinted that drivers tended to view cyclists wearing helmets as more “serious, sensible and predictable road users.”

Did any of this matter on the road, or did cars simply pass cyclists as cyclists, more or less randomly? To find out, Walker mounted a Trek hybrid bicycle with an ultrasonic distance sensor and set out on the roads of Salisbury and Bristol. He made trips wearing a helmet and not wearing a helmet. He made trips at different distances from the edge of the road. And he made trips dressed as a man and dressed as a woman, wearing, as a rough signifier of gender, a “long feminine wig.” After he had crunched the data, the numbers revealed an interesting set of patterns. The farther he rode from the edge of the road, the less space cars gave him. When he wore a helmet, vehicles tended to pass closer than when he did not wear a helmet. Passing drivers may have read the helmet as a sign that there was less risk for the cyclist if they hit him. Or perhaps the helmet dehumanized the rider. Or—and more likely, according to Walker—drivers read the helmet as a symbol of a more capable and predictable cyclist, one less likely to veer into their path. In either case, the helmet changed the behavior of passing drivers.

Finally, drivers gave Walker more space when he was dressed as a woman than as a man. Was this a “novelty effect” based on the fact there are statistically fewer female cyclists on England’s roads? Or were drivers simply thinking, “Who is this crazy man-cyclist wearing that terrible wig?” Or were drivers (whose gender Walker was not able to record) giving women cyclists more room out of some sense of politeness or, perhaps, as he suggests, because they were operating with a stereotypical idea of women cyclists as less predictable or competent?

Interestingly, the possible gender bias, however misguided, echoes the intersection study mentioned earlier, in which drivers were more likely to yield the right-of-way if a female driver was approaching. Drivers, whether aware of it or not, seem to rely on stereotypes (a version of Walker’s “mental models”). Indeed, stereotypes seem to flourish in traffic. One reason, most simply, is that we have little actual information about people in traffic, as with the “Bumper of My S.U.V.” dilemma. The second reason is that we rely on stereotypes as “mental shortcuts” to help us make sense of complex environments in which there is little time to develop subtle evaluations. This is not necessarily bad: A driver who sees a small child standing on the roadside may make a stereotypical judgment that “children have no impulse control” and assume that the child may dash out. The driver slows.

It does not take a great leap to imagine, however, the problems of seeing something that does not conform to our expectations. Consider the results of one well-known psychological study. People were read a word describing a personal attribute that confirmed, countered, or avoided gender stereotypes. They were then given a name and asked to judge whether it was male or female. People responded more quickly when the stereotypical attribute matched the name than when it did not; so people were faster to the trigger when it was “strong John” and “gentle Jane” than when it was “strong Jane” and “gentle John.” Only when subjects were actively asked to try to counter the stereotype and had a sufficiently low “cognitive constraint” (i.e., enough time) were they able to overcome these automatic responses.

Similarly, the drivers passing Walker on his bicycle seemed to be making automatic judgments. But did the stereotype of the helmet-wearing Walker as a competent, predictable cyclist help or hurt in the end? After all, motorists drove more closely to him. Would he have been better off wearing a wig, a Darth Vader mask, or anything else that sent a different “traffic signal” to the driver? The answer is unclear, but Walker came away from the experiment with a positive feeling about what looking human can mean in traffic. “You can stick a helmet on and it will lead to measurable changes in behavior. It shows that as a driver approaches a given cyclist, they can make an individual judgment on that person’s perceived needs. They are judging each person as individuals. They’re not just invoking some default behavior for passing cyclists. That’s got to be encouraging.”

Our traffic lives are ruled by anonymity, but this doesn’t mean we give up trying to infer things about the people we encounter, or acting on those things in ways we may not even register.

Waiting in Line, Waiting in Traffic:
Why the Other Lane Always Moves Faster

When people are waiting, they are bad judges of time, and every half minute seems like five.

—Jane Austen, Mansfield Park

When was the last time you were angry at something that seemed out of your control? There is a very good possibility it was in one of three situations: being stuck in a traffic jam; waiting in line at a bank, an airport, a post office, or some such place; or being placed on hold for a “customer service representative.”

In all three cases, you were in a queue. Of course, you were probably more angry in the first and third cases, because you were most likely in the privacy of your car or home. But there is ample opportunity for you to get angry in a public queue, which is why corporations have spent a lot of money, and thought long and hard, not only about how to reduce queues but how to make them feel shorter.

In traffic, we wait in several kinds of queues. Traffic lights cause the most traditional kind. The traffic light takes the place of the “server.” A particularly slow server, like a particularly slow traffic light, bears the brunt of our frustration. As with traditional queues, traffic engineers try to estimate the flow of “arrivals.” Do cars arrive in a random way, or in a “Poisson” process (after the French mathematician Siméon-Denis Poisson), as in a bank queue? Or is it non-Poisson, nonrandom (think of immigration queues at airports, which are periodically flooded by “platoons” of deplaning passengers)? Traffic engineers extend the “cycle time” during peak hours in the same way a Starbucks might add employees during the morning rush.

There are also “moving queues,” as when you’re in the faster left-lane on a highway, stuck behind what engineers call a “platoon” of vehicles. As some vehicles shift to slower lanes, you can “move up” the queue. If someone is in your way you might flash your lights or crowd their tail, which is roughly the equivalent of lightly coughing or tapping the shoulder of someone who is daydreaming in line ahead of you and has forgotten to move. You may have noticed how we tend to do this even when it clearly will not change the overall wait time, as if the sight of empty space makes us anxious.

Traffic congestion baffles traditional queue logic. We are waiting in a queue, but we often do not know where it begins or ends. How are we to measure our progress? Whether or not traffic always acts like a traditional queue, what’s interesting is that it seems to affect us in exactly the same way. David Maister, an expert in “the psychology of queuing,” has come up with a series of propositions about waiting in line. Strikingly, they all seem to hold true for traffic.

Take proposition no. 1: “Unoccupied time feels longer than occupied time.” This is why grocery stores put magazines near the cashiers, and why we listen to radios or talk on cell phones in our cars. Or proposition no. 3: “Anxiety makes waits seem longer.” Ever been stuck in traffic on your way to an important meeting or when you were low on gas? Or proposition no. 4: “Uncertain waits are longer than known, finite waits.” This is why highway engineers use CMS, or “changeable message signs,” to tell us how long a stretch of commute will take. Studies suggest that when we know the exact time of a wait, we devote less attention to thinking about it. Traffic engineers in Delhi, India, have put up “countdown signals” on a number of traffic lights, marking the number of seconds until the light turns green, for this very reason.

Also worth considering is proposition no. 6: “Unfair waits are longer than equitable waits.” Think of ramp meters, those signals that delay drivers’ entrance onto the freeway. Drivers fume: Why should I have to wait on the ramp while the freeway is moving? One study found that people thought of waiting on the ramp as 1.6 to 1.7 times “more onerous” than waiting on the highway itself. The more people understand the purpose of ramp meters (which I will discuss in Chapter 4), the less bothersome the wait becomes. This relates to proposition no. 5: “Unexplained waits are longer than explained waits.” Hence our frustration when we find no “cause” for a traffic jam. If we know there is an accident or construction, the delay is easier to process. Proposition no. 8 is appropriate, too: “Solo waiting feels longer than group waiting.” One study found that solo drivers placed the highest value on saving time in traffic. The implication is that they are more affected by delays than people not traveling alone, which is ironic, considering that under HOV lane schemes people traveling in groups often move faster.

Queues, wherever they occur, play strange games with our perception of time, our feeling of satisfaction, even our sense of “social justice.” Studies have shown that people routinely overestimate the amount of time they have actually spent in a queue, and thus are less satisfied when they get served. (This is why Disney World inflates the posted waiting times for their attractions.) And while you might think that the most important factor of a queue is how many people are in front of the person waiting, research suggests that the number behind is significant as well. One study, at a Hong Kong post office, found that the more people there were behind a person waiting in a queue, the less likely they were to “renege,” or quit. The queue might have suddenly seemed more valuable. Another theory is that when people are anxious—as is common in queues—they’re more likely to make “downward” comparisons than “upward”: instead of “Look how far along they are,” at the front of the line, they think, “At least I’m better off than you at the back.”

What really seems to rankle us is seeing people get ahead. This is why, says Richard Larson, director of the Center for Engineering Systems Fundamentals at the Massachusetts Institute of Technology and one of the world’s leading authorities on queues, any number of companies—from banks to fast-food chains—have switched from systems in which multiple lines feed multiple servers to a single, serpentine line. “There’s a theorem in queuing theory that says the average wait in either configuration is the same,” Larson explains. Yet people prefer the single line, so much so that they have said they would be willing to wait in a longer line at Wendy’s, the hamburger chain where a single line is used, than at a shorter line at McDonald’s, which uses multiple lines. Why? Social justice, says Larson. “If you have the single serpentine line, you’re guaranteed first come, first served. If you have the multiple lines, you have what happens at McDonald’s at lunchtime. You have the stress of joining a line with high likelihood that somebody who’s joined a queue next to you will get served before you. People get really irritated with that.”

This happens all the time in traffic, in which reneging on the queue is often impossible. It’s why I changed lanes and became a “late merger,” and why people get frustrated with late mergers. (I will explain shortly why they shouldn’t.) Sometimes, changing lanes (i.e., moving to a different queue) is actually a useful strategy. Often, however, it gets us no real gain. A Canadian television news program had two drivers commute along the same route on a highway at the same time. One was told to make as many lane changes as possible, the other to avoid changing lanes. The chronic lane changer saved a mere four minutes out of an eighty-minute drive, which hardly seems worth it. The stress involved in making all those changes probably took more than four minutes off the driver’s life.

One reason why many people constantly change lanes was demonstrated in a fascinating experiment conducted by Donald Redelmeier and Robert Tibshirani, a clinical epidemiologist in Toronto and a statistician at Stanford University, respectively. Using a simple computer simulation of two lanes’ worth of congested traffic obeying typical traffic behavior, as well as a video of an actual congested highway, the researchers found an illusion when looking at a sample driver: Even though the subject car had as many “passing events” as it had “overtaking events”—meaning it was maintaining the same overall relative pace as the next lane—the car spent more time being passed by cars than it did passing them.

Traffic, for reasons I will later explain, tends to act like an accordion: As traffic slows in a jam, it compresses; as congestion eases, the accordion “opens” and cars begin to speed up. Because of the uneven nature of stop-and-go traffic, these shifts happen in different lanes at different times. A driver in a temporarily opening lane may very quickly pass a cluster of compressing cars in the next lane. But then he will find himself in the compressing lane. And what happens? He spends more time watching those vehicles zip by in the next lane. To make matters worse, the researchers found that the closer a driver drove to the car in front of him, and the more glances he made to the next lane, the worse the illusion seemed.

Something else might also be helping to create the illusion. Drivers spend most of their time—anywhere from 80 percent to over 90 percent, studies have found—looking at the forward roadway. This includes, of course, the adjacent lane; estimates are that for every two glances we make at our own lane, we make one glance at the next lane—simply so we can actually stay in our lane. This means we are highly aware of vehicles passing us. We spend only about 6 percent of our driving time looking in the rearview mirror. In other words, we’re much more aware of what is passing us than what we have passed.

The fact that we spend more time seeing losses than gains while driving in congestion plays perfectly into a well-known psychological theory called “loss aversion.” Any number of experiments have shown that humans register losses more powerfully than gains. Our brains even seem rigged to be more sensitive to loss. In what psychologist Daniel Kahneman has called the “endowment affect,” once people have been given something, they are instantly more hesitant to give it up.

Do you remember the childlike glee you felt the last time you found a parking spot at the mall on a crowded day? You may have left the spot with a certain reluctance, particularly if someone else was waiting for it. Studies have shown that people take longer to leave a parking spot when another driver is waiting, even though they predict they will not. It’s as if the space suddenly becomes more valuable once another person wants it. In strict terms it does, even though it is no longer of intrinsic value to the person leaving it. This sensitivity to loss might also help explain the late-merger dilemma described in the Prologue. What really triggers the decision to change lanes is not so much the coolly rational assessment of underused transportation capacity but the fact that people kept passing while the early mergers stood still. The late merger’s gain is perceived as the early merger’s loss.

But what’s the harm in merely changing lanes, anyway? One study, by the National Highway Traffic Safety Administration, found that almost 10 percent of all crashes involved lane changes. How many of those lane changes were necessary, and how many were discretionary? Do we really understand what is involved in the choices we are making? It is this last question that was at the heart of Redelmeier and Tibshirani’s lane-changing study, for Redelmeier, a soft-spoken, sober doctor who spends a third of his time seeing patients at the Sunnybrook Health Sciences Centre in Toronto, has a privileged window on to the consequences of the decisions we make while driving.

“I mostly look at individuals that get seriously damaged in the aftermath of a crash,” he told me in his office. “For many of them, their lives are ruined forever. For many of them, there’s also this tremendous sense of remorse or chagrin—you know, if only they had behaved slightly differently, they would have never ended up in the hospital. There’s a real element of almost counterfactual thinking that goes on in the aftermath of a crash. When someone comes down with pancreatic cancer there’s a lot of suffering that’s going on, but they usually don’t start second-guessing themselves about how things could have been done differently in order to avoid this terrible predicament, whereas with motor vehicle crashes it’s a very strong theme. That got me thinking how complicated driving is.”

We may be doing things in traffic for reasons we do not even understand as we are acting. But how we can resist things like the next-lane-is-faster illusion? Redelmeier suggests, if not completely seriously, that we might feel better if we spent more time looking in the rearview mirror. Then we could make “downward comparisons,” as with the poor saps in the Hong Kong post office, and not feel so bad. But we would also quite likely collide with the vehicle in front of us, and then cars in the next lane really would be going faster. The very nature of driving, posited as a constant progress along an endless queue, defeats us. Traffic messes with our heads in a strangely paradoxical way: We act too human, we do not act human enough.

Postscript: And Now, the Secrets of Late Merging Revealed

People are afraid to merge on freeways in Los Angeles.

—Bret Easton Ellis, Less Than Zero

We humans have achieved great things. We have unlocked the once-unfathomable human genetic sequence, sent space probes to the far reaches of the solar system, and even managed to freeze a beam of light. But there’s one scientific conquest that has largely eluded us. It’s all the more puzzling because, on the face of it, it seems so mundane: We have not found a way to make drivers merge with the most efficiency and safety on the highway.

The situation described in the Prologue that I encountered on the Jersey highway is known in the traffic-engineering world as a “work-zone merge.” Work zones, it turns out, are among the most complex and dangerous areas on the highway. Despite the signs often warning of large penalties for striking a worker (or pleas like SLOW DOWN, MY DADDY WORKS HERE), they are much more dangerous for the drivers passing through them than for the workers—some 85 percent of people killed in work zones are drivers or passengers. The reasons are not difficult to imagine. Drivers moving from an incredibly fast, free-flowing environment are suddenly being asked, sometimes unexpectedly, to come to a crawl or even a full stop, perhaps change lanes, and pass through a narrow, constricted space filled with workers, heavy machinery, and other objects of visual fascination.

And then there’s the inevitable point at which two lanes of traffic will be forced to become one (or three to become two, etc.), when the early mergers, the late mergers, and everyone in between are suddenly introduced to one another. This can get sticky. It seems that even though (or maybe because) we’re all tossed together on the road, drivers are not all that comfortable with interacting; a survey undertaken by the Texas Transportation Institute found that the single most common cause of stress on the highway was “merging difficulties.”

Traffic engineers have spent a lot of time and money studying this problem, but it is not as simple as you might think. The “conventional merge” site, the sort I experienced on the highway in New Jersey, works reasonably well when traffic is light. Drivers are warned in advance to move into the correct lane, and they do so at a comfortable distance and speed, without a “conflict” with a driver in the other lane. But the very nature of a work zone means that traffic is often not light. A highway going from two lanes to one, or experiencing a “lane drop,” loses at least half of its capacity to process cars—even more if drivers are slowing to see what is going on in the work zone itself. Because the capacity is quickly exceeded by the arriving cars, a “queue” soon forms. The queue, inevitably, is longer in the lane that will remain open, probably because signs have told drivers to move there.

This causes more problems. As the queue grows, it may move far back up the highway—engineers call this “upstream”—perhaps even past the signs warning of the lane closure. This means that newly arriving drivers will be encountering an unexpected queue of cars. Seeing no reason for it, they will be unaware that they’re in a lane that is due to close. Once they learn this, they will have to “force” their way into the queued line, whose drivers may view the new arrivals, fairly or not, as “cheaters.” As the entering drivers slow or even stop to merge, they create a temporary second queue. Drivers who grow frustrated in the queued line might similarly force their way into the faster open lane. This is all a recipe for rear-end collisions, which, as it happens, are among the leading types of crashes in work zones.

To improve things, North American engineers have responded in two basic ways. First, there is the school of Early Merge. To tackle the “forced merge” problem, Early Merge spreads out the whole merging zone. Drivers are warned by a sign several miles in advance of the “taper” that a lane drop is coming, rather than the twelve hundred feet or so in the conventional merge. “No Passing Zones” signs are often placed in the lane that will close. The earlier notice, in theory, means drivers will merge sooner and with less “friction,” as engineers politely say, and will be less surprised by a sudden queue of stopped cars. Indeed, a 1997 study of an Indiana construction site using this system showed very few forced merges, few “traffic conflicts,” and few rear-end collisions.

Early Merge suffers from a critical flaw, however. It has not been shown to move vehicles through the work zone more quickly than the conventional merge. One simulation showed that it actually took vehicles longer to travel through the work zone, perhaps because faster-moving cars were being put behind slower-moving cars in a single lane sooner than they might naturally have gotten there, thus creating an artificial rolling traffic jam. An Early Merge system would also seem to require some kind of active law enforcement presence to make sure drivers do not violate the concept. As we all know, the presence of a police car on the highway has its own unique effects on traffic.

The second school, Late Merge, was rolled out by traffic engineers in Pennsylvania in the 1990s in response to reports of aggressive driving at merge locations. In this system, engineers posted a succession of signs, beginning a mile and a half from the closure. First came USE BOTH LANES TO MERGE POINT, then a ROAD WORK AHEAD or two, and finally, at the lane drop: MERGE HERE TAKE YOUR TURN.

The beauty of the Late Merge system is that it removes the insecurity or anxiety drivers may feel in choosing lanes, as well as their annoyance with a passing “cheating” driver. The Late Merge compresses what may normally be thousands of feet of potential merging maneuvers to a single point. There is, presumably, no lane jumping or jockeying, as the flow or speed should be no better or worse in one lane than another—hence there are fewer chances for rear-end collisions. Because cars are using both lanes to the end point, the queue is cut in half.

The most surprising thing about the Late Merge concept is that it showed a 15 percent improvement in traffic flow over the conventional merge. It turns out that the Live Free crowd was right. Merging late, that purported symbol of individual greed, actually makes things better for everyone. As one of my Live Free responders had succinctly put it: “Isn’t it obvious that the best thing to do is for both lanes to be full right up to the last moment, and then merge in turn? That way, the full capacity of the road is being used, and it’s fair on everyone, rather than a bunch of people merging early and trying to create an artificial one-lane road earlier than necessary.” (Note: This does not apply to people “late-merging” their way to the head of queues at off-ramps and the like, as those late mergers may temporarily block an otherwise free-flowing lane of traffic, not to mention greatly irritating those already queued.)

It’s not just North Americans who have problems with merging. The United Kingdom’s Transport Research Laboratory, in an internal report looking at new work-zone merging treatments, noted the “poor utilization of the closed lane well in advance of the taper,” which it partially attributed to “vehicles blocking this lane deliberately to prevent others from ‘queue jumping.’” In the 1990s, U.K. road authorities began experimenting with new signs and the so-called zipper merge, used in Germany since the 1970s. Rather than simply warn of an impending lane closure, the signs, beginning well in advance of the lane drop, advised drivers, WHEN QUEUING USE BOTH LANES and MERGE IN TURN. But the TRL, in trials on Scottish motorways, found that while the system reduced queue lengths, it didn’t make traffic flow any more smoothly through the work zone. (Part of the problem may be that drivers are often still unclear about exactly where to merge: where the sign tells them to, or where the two lanes become one, or somewhere in between?) Most European traffic engineers try to avoid merging problems wherever possible by simply eliminating the need to merge. Instead, they carve out extra lanes by making the remaining lanes much smaller; this not only preserves multiple lanes, it forces drivers to slow, which is also safer.

One important caveat of the American Late Merge is that it achieved its superior performance in congested conditions—the time, of course, when work-zone merging becomes most problematic. When traffic is flowing freely, there are obvious logistical problems with driving at 75 miles per hour to the end of a lane and then “taking your turn” at the last moment. That is why traffic engineers began working on a refinement, the “Dynamic Late Merge.” This employs “changeable message signs” and flashing warnings that are activated when the traffic volume reaches the point at which late merging would be more desirable. When traffic is light, the signs call for a conventional merge.

But as a Dynamic Late Merge trial undertaken by the Minnesota Department of Transportation on Interstate 35 in the summer of 2003 showed, the best-laid plans of traffic engineers often run aground on the rocky shoals of human behavior. While the experiment was able to reduce the length of queues by 35 percent, it found that vehicle volume through the merge actually decreased.

What happened? It seemed that many drivers, despite the instructions urging them to USE BOTH LANES, either did not understand the command or refused it. Only a few drivers in the lane to be closed actually made it to the sign that said, quite plainly, MERGE HERE. Some vehicles simply merged early into the “continuous lane,” while others found themselves blocked by trucks and other self-appointed, lane-straddling “traffic cops” who, despite the messages, seemed intent on preserving a single queue—often to the point of aggressively weaving to block a vehicle from passing. Perhaps because they have the most difficulty accelerating and merging at work zones, truck drivers often seem intent on preserving a single queue. Some drivers in the ending lane were observed “pacing” themselves next to a car in the open lane, as if they thought it rude to go faster than anyone else (this was Minnesota, after all, the home of that Paul Bunyan–sized politeness they call “Minnesota Nice”). When this happened, the drivers following them seemed to simply give up and perform an early merge. None of this was what the DOT had in mind, as it bemoaned in a report: “These multiple merging locations created unnecessary disruptions in the traffic flow, slowing vehicles and creating more stop-and-go conditions than necessary.”

The result was that drivers, whether acting out of perceived courtesy or a sense of vigilante justice, thought they were doing the right thing. In fact, they were slowing things down for everyone. One might be willing to forgive the loss in time if they were somehow making the work zone safer or less stressful, but this is not the case; rather, they created confusion by not following instructions or by acting hostile toward those who tried to do so. The Minnesota DOT seemed quite puzzled: “For some unknown reason, a small number of drivers were unwilling to change their old driving behaviors.” Things got better over time—but by then the construction project was finished.

Beyond simple engineering, there seems to be a whole worldview contained in each of the merge strategies that have been tried. The Early Merge strategy implies that people are good. They want to do the right thing. They want to merge as soon as possible, and with as little negotiation as possible. They can eschew temptation in favor of cooperation. The line might be a little longer, but it seems a small price for working toward the common good. The Late Merge strategy suggests that people are not as good, or only as good as circumstances allow. Rather than having people choose among themselves where and when and in front of whom to merge, it picks the spot, and the rules, for them. Late Merge also posits that the presence of that seductively traffic-free space will be too tempting for the average mortal, and so simply removes it. And the conventional merge, the one that most of us seem to find ourselves in each day? This is strictly laissez-faire. It gives people a set of circumstances and only a vague directive of what to do and leaves the rest up to them. This tosses the late mergers and the early mergers together in an unholy tempest of conflicting beliefs, expectations, and actions. Perhaps not surprisingly, it performs the worst of all.

I suggest the following: The next time you find yourself on a congested four-lane road and you see that a forced merge is coming, don’t panic. Do not stop, do not swerve into the other lane. Simply stay in your lane—if there is a lot of traffic, the distribution between both lanes should be more or less equal—all the way to the merge point. Those in the lane that is remaining open should allow one person from the lane to be closed in ahead of them, and then proceed (those doing the merging must take a similar turn). By working together, by abandoning our individual preferences and our distrust of others’ preferences, in favor of a simple set of objective rules, we can make things better for everyone.