Driving is something that millions of people do every day, and every day most people arrive safely at their destination. Our individual successes at the wheel makes driving second nature, and according to author Tom Vanderbilt, therein lies the problem. Vanderbilt, who writes for magazines like Wired and Slate, has carefully considered the act of driving in all its facets, save one: environmental impact. As he puts it, “it will be easier to remove the internal-combustion engine from the car than it will to remove the driver.”

This sense of inevitability permeates Traffic. Vanderbilt describes just how improbable the act of driving safely is, using the perspective of cognitive brain science and his chilling description of the psychological phenomena known as risk homeostasis. In between are some relatively cheerful examples of the coping strategies that we employ to enable us to get where we’re going safely. For instance, who knew that the incredible whirling chaos of Rome or New Delhi, where vehicles of all description turn two-lane roads to five-lane roads, actually represents a complex equilibrium of traffic efficiency? Or that in some places, having fewer safety signs actually makes roads more safe?

In many cases, Vanderbilt sees the true culprit behind traffic accidents as driver boredom. In developed nations with sophisticated roadways, engineers have made cars and roads so safe that they do too much of the thinking for the driver. This allows drivers to think of other things, talk on cellphones, air drum, put on makeup, or worst of all, fall asleep at the wheel. Furthermore, according to theorists of risk homeostasis, everyone knows that driving is inherently risky, and everyone is willing to accept a particular level of risk. The more aware of the risk, the better we tend to drive. Unfortunately, the safer our vehicles and roads become, the more willing we are to take risks. At ever-increasing speeds, this is leading to a higher frequency of fatal accidents. One reason more people are killed in fair weather conditions is because people slow down and pay more attention when conditions are bad. A similar thing happens in the absence of street signs. As one interviewee who studies traffic put it, the way to make everyone drive safer is to install a dagger on the steering wheel pointed at the driver’s heart.

Rest assured, Traffic is far from fear-mongering hysteria. Vanderbilt maintains a measured voice as he interviews traffic experts from around the world. The feeling of dread, however, comes from the realization that bad driving is not something that happens because we are unlucky, but rather something that happens when we are unthinking.