Traffic (the car kind, not the drug kind)

The book I'm reading right now, Traffic by Tom Vanderbilt, has some fascinating information he has gathered from studies. Here is a sample of his writing style that shows how densely researched his book is (endnotes cite the studies he refers to).

Studies have suggested that drivers of small cars take fewer risks (as judged by speed, distance to the vehicle ahead of them, and seat-belt wearing) than drivers of larger cars. Many drivers, particularly in the United States, drive sport-utility vehicles for their perceived safety benefits from increased weight and visibility. There is evidence, however, that SUV drivers trade these advantages for more aggressive driving behavior. The result, studies have argued, is that SUVs are, overall, no safer than medium or large passenger cars, and less safe than minivans.

Studies have also show that SUV drivers drive faster, which may be a result of feeling safer. They seem to behave differently in other ways as well. A study in New Zealand observed the position of passing drivers' hands on their steering wheels. This positioning has been suggested as a measure of perceived risk--research has found, for instance, that more people are likely to have their hands on the top half of the steering wheel when they're driving on roads with higher speeds and more lanes. The study found that SUV drivers, more than car drivers, tended to drive either with only one hand or with both hands on the bottom half of the steering wheel, positions that seemed to indicate lower feelings of risk. Another study looked at several locations in London. After observing more than forty thousand vehicles, researchers found that SUV drivers were more likely to be talking on a cell phone than car drivers, more likely not to be wearing a seat belt, and--no surprise--more likely not to be wearing a seat belt while talking on a cell phone.

One of the themes running through this book is the danger of perceived safety, and he points out time after time how much more safely we drive when we perceive risk--that is one of the reasons why, for instance, roundabouts like the ones in European countries have 90% (yes, 90%!!) fewer fatal accidents than standard intersections. When we approach a roundabout, we have to pay attention because we perceive a higher risk, while approaching an intersection with a green light makes us feel safe, often leading to us missing dangers like drivers speeding through red lights.

It's a fascinating read.