Driving is a common activity throughout the world, but it also reveals a whole host of quirks and tics of human nature. In this exploratory sociology and psychology of traffic, journalist Tom Vanderbilt holds a mirror up to road culture and wonders what it means.

Do you ever feel like you have that unenviable knack for selecting the slowest lane on the highway? Or maybe you have just concluded that there is an inscrutable randomness to traffic’s viscous flow, and that you “win” the race some days, and “lose” it others.

And then, of course, there are unspoken rules of the road that won’t get you a traffic citation, but they will win you some dirty looks and white-knuckled ire. What happens, for example, when signs on the side of the road alert drivers to a lane closing a mile up the road? Most people instinctively merge before they get caught in the bottleneck, and then glare angrily at the insufferable opportunists who breeze ahead while the rest of the mechanical herd idles bumper-to-bumper.

But why is it that we neurotically yank our vehicles out of the ending lane the first chance we get? And why do we become so annoyed and self-righteous when we watch the late mergers zoom past us? Of course, this is not a universal position. Some people (probably late mergers) view a belated lane change as maximizing the highway’s utility, and that it is actually faster for everyone when not everyone merges at once. The road to traffic jams is paved with good intentions, according to the contrarian camp. It is the people attempting to be “nice” and “courteous” who are clogging up the interstate.

What is interesting about traffic scenarios is that people assume they have the moral high ground and then there are some nefarious “others” with seared consciences and blackened hearts who do things differently. At the end of the day, these differences in driving habits have much less to do with the law and much more to do with personal intuitions. Very few people reference legal statutes to defend their actions behind the wheel.

The gap between formal and informal expectations on the road raises questions of how culture influences traffic. After all, people from numerous walks of life converge on these miles-long concrete slabs and interact in a consistent way, and yet there are clear differences in how traffic moves between Stockholm and New Delhi, for example. What are we to make of this? What can traffic tell us about ourselves?

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Have you ever pondered how much is involved in driving? You are constantly scanning the lay of the land, staying vigilant to obstacles and dangers, relying on your spatial reasoning skills, and anticipating the actions of other drivers, bikers, and pedestrians (and rickshaw walas and cows if you’re driving in India). Some studies estimate that driving draws on 1,500 “subskills.” Another study concluded that the rate at which fresh information flies at us, even at the relatively low speed of 30 miles per hour, is the equivalent of reading 440 words per minute, while simultaneously processing a long series of pictures coming to us in rapid succession.

Driving is so common that we miss how remarkable a skill it is. The groups most acquainted with the task’s complexity are those designing self-driving cars. The best engineers scratch their heads and wonder what it takes for A.I. to drive as well as people. It’s quite a conundrum: How fast should the car be designed to drive? Should it always drive that speed?  What if there is an object in the car’s path? What kind of object is it? Does that object require a hard stop, a slow stop, a lane change, or a no change at all? The answer depends on understanding the particular circumstances. Is it a child in the road? A pothole? A plastic bag? Each of these requires a different response.

Even the brightest engineers have difficulty creating machines that will respond appropriately to the road’s ever-changing panoramas, but people, for the most part, navigate this complexity and unpredictability with a great deal of finesse.

Before we pat ourselves on the back, another interesting set of data reveals that we as individuals tend to overestimate our driving skills. Exemplifying what social scientists call “optimistic bias,” studies in the United States, New Zealand, and France all find that most people consider themselves above-average drivers. From a statistical perspective, it’s impossible for them to be right. On average, people consider themselves above the average.

Driving is hardly the only domain in which we overestimate our abilities, but we seem especially vulnerable to overconfidence when we are in the driver’s seat. Research indicates that drivers tend to be far more assured that they will avoid a crash than their passengers. This makes sense because of the tendency to overestimate ourselves when we have some control over circumstances. Drivers have the steering wheel in their hands; their passengers use their hands to cover their eyes or fold them in a quick prayer.

And, of course, we rarely question our driving methods (especially men), but we do expect others to change. We like the no texting laws for everyone else, but chafe against them ourselves because our driving is the exception. And we conveniently save our moments of self-evaluation for when there is a moron ahead of us straddling lanes as he puts the finishing touches on a text. Without feedback (or openness to that feedback), we will continue driving the way we always do: “above average.”

In sum, we might maneuver the highways and byways far better than A.I., but we also tend to overestimate our driving skills—as is common in situations where we are in control, performing mundane tasks like driving.

According to one Oxford zoologist, there’s no creature better at building traffic systems than ants. Some swarm species compete against and even cannibalize themselves. Mormon crickets in the southwestern US, for example, move quickly across desert and scrub because they are hungrily trying to catch their neighbor ahead of them while also desperately striving to avoid the hungry neighbor behind them. They’ve been described as “black carpets” when they’re on the move, and they decimate crops and each other.

But ants are different. They cooperate. They help each other rather than eat each other. They form bridges and rafts, they create elaborate three-way highways, and their lanes merge seamlessly. No sense of entitlement clogs up the merge lanes. No ant blocks another’s entrance. Their object of serving the queen and colony is an all-consuming impulse, and they do it with mind-boggling efficiency. If one worker brings back a piece of food that is just too big to manage efficiently, others will join and assist until they (somehow) sense there are enough limbs on deck to move that crumb along at an acceptable clip.

Ants don’t get into traffic jams. Why do we? Under special circumstances, we manage congestion pretty well, but it’s a gargantuan effort. At the Oscars, for example, reporters are standing at the corner of Hollywood Boulevard and Highland eager to talk to celebrities about their films or attire, but no one asks the far more bewildering question of how hundreds of limousines and other luxury vehicles managed to arrive at the Kodak Theater in a timely fashion. If you have ever visited Los Angeles, you understand the city’s reputation for abysmal traffic is well deserved.

Without special-ops style traffic engineering to coordinate Los Angeles traffic flow the night of the Oscars, hundreds of millions of fans around the world would miss the star-studded spectacle—as would the stars themselves.

Normally, the city’s traffic lights run on an algorithmic system without much outside interference, but for the Oscars, the head engineer oversees a team to ensure smooth sailing for all celebrity vehicles. He wields a walkie-talkie in one hand, his cell in the other, and is ready to receive landline calls as they come in—all while watching the screens and adapting instructions based on traffic updates. It’s a hectic night, but it’s one in which the head operator gets a taste of playing God, or at least prompting ripple effects that emanate through the entire City of Angels. Part of the task is not just timing lights well, but also coordinating with squads of “picketing engineers,” protestors strategically placed at certain intersections who cross streets in order to slow down traffic in certain quarters so it can flow in others. These protestors await his instructions on which streets to clog and when.

Perhaps it’s a bit unfair to compare our stress-inducing traffic systems to the fluid coordination of ant colonies. Ants have been refining their systems over centuries and centuries, but we have only recently begun transporting ourselves via motorized metal boxes. Despite remarkable innovations in traffic flow coordination that have allowed twice as many cars to pass a day as engineers intended, we are still relatively new to this pattern of movement. Moreover, ants are unified in their purpose, but human interests are as disparate as the people who hold them. We are essentially competitors on the road, not cooperators, more like Mormon crickets than ants (though we hopefully refrain from cannibalizing each other).

There is no other city on earth issuing more traffic reports or commissioning more traffic reporters than Los Angeles. If you view the city from the air during rush hour, the streams of traffic resemble an ant colony, but as we know, it’s way more complicated than that. We go where we want, when we want and we are looking out for number one at the end of the day.

In 1951, there were 852 road fatalities in the entire country of China. That same year, the United States tallied up over 35,000. Nearly half a century later, in 1999, China’s annual death toll on the road was 84,000, whereas the United States reported 41,508. Road-related deaths in the US climbed to just slightly over five decades, but by the end of that same time frame, China’s fatality count was nearly 1,000 times higher than its count in 1951.

How do we understand such a colossal discrepancy? Part of the explanation lies in the number of vehicles on the road. In 1951, there were only 60,000 vehicles in China, but nearly 50 million in the United States. By the turn of the 21st century, there were 50 million vehicles in China, and 200 million in the United States. China only had a quarter of the number of vehicles that the US had, but they had twice as many crashes. Clearly, the number of vehicles on the road can’t fully explain rates of car crashes.

The more vehicles there are, the greater opportunity for crashes and the more fatalities will result, but fatality rates reach a point where they peak—and then begin to steadily decline. So the total number of crashes and fatalities may rise just because there are more cars on the road, but the rate at which those fatalities occur (relative to number of cars on the road) declines.

In the mid-20th century, a British statistician named R. J. Smeed noted this phenomenon, which is now referred to as Smeed’s law. Smeed proposed that there is a period in which a society has to adjust to more cars on the road, and increased fatalities are growing pains in a societal coming-of-age process before the culture adjusts to a new normal. Part of that adjustment is getting serious about addressing the death rates: making better roads and highways, more stringent vehicle safety measures, stricter traffic laws, and stiffer penalties for breaking them. In the United States, for example, annual fatalities peaked in the 1960s, and public outcry led to improved rules and regulation. Recently, China’s road fatality rate has begun to dip as well. 

Countries have to pay a strange toll on their road to development. As they build out infrastructure for highways and more vehicles fill those roadways, the rate of accidents increases. More cars mean more accidents and fatalities, but only up to a certain point—which Smeed mapped out more than half a century ago.

One in 10 road-related fatalities occurs in India—around 100,000 annually. And while each of those is a tragedy, there is a strange miracle at work on India’s streets. If you ever visit India, you might be surprised that there are not more deaths. According to one government official, there are 48 different means of transportation in the city of Delhi, including ox-drawn carts, buses, cycle rickshaws, the iconic green-and-yellow auto rickshaws, vintage Ambassador taxis, and motorcyclists bearing their sari-clad wife riding side-saddle with small children dangling from the crook in her arm. All of these forms of transportation vie for space in the megacity’s congested thoroughfares and alleyways.

A group of British police officers said they could predict driver behavior in the United Kingdom with 90 percent accuracy, but when they came to Delhi and attempted to guess driver decisions, they could only accurately predict driver behavior 10 percent of the time—which is another way of saying they could not predict behavior at all. Most Delhi drivers are aware of the rules of the road. The government does its best to encourage responsible driving with signs that read “Don’t dream otherwise you’ll scream” or something equally jarring.  But even pithy snatches of macabre poetry fail to carry the day. Delhi officials estimate 100 million road violations are committed daily.

Part of the reason that Delhi drivers commit so many infractions to the well-codified, but less-well-enforced rules of the road is that drivers creatively adapt to traffic violations with their own traffic violations. If pedestrians and bikes move through a bus lane (because they have no footpath), then bus drivers have to stop in the middle of the road to pick up passengers waiting at the bus stand.

To outside eyes, Delhi traffic looks like senseless, cacophonous mayhem. But there is so much that is unexpected on the Delhi roads that drivers expect the unexpected, which gives rise to an entirely new rhythm and culture to traffic flow. As one autorickshaw driver put it when asked about driving in Delhi, “Good brakes, good horn, good luck.”

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