"Traffic" pokes into the pedal-pushing, horn-honking psyche of the American driver

"Traffic: Why We Drive

the Way We Do (and

What It Says About Us)"

by Tom Vanderbilt

Knopf, 402 pp., $24.95

Tom Vanderbilt shares a funny story told to him by the Rev. David Rowe, who leads a congregation in a wealthy Connecticut suburb and who improbably is also a fan of punk band Green Day. Spotting a car with a Green Day sticker as he was out driving, Rowe honked to show his solidarity. The driver replied by giving Rowe the finger.

Traffic, as Vanderbilt shows in this fascinating, surprising study, is a hall of mirrors, even to those who study it for a living, not to mention those who find themselves stuck in it.

For starters, how do we communicate with other drivers? Poorly, says Vanderbilt, who writes on science and technology for Wired, The Wall Street Journal and Popular Science, among other publications.

When drivers cut us off, do they even know what they've done? And if we cut them off in turn, to "teach them a lesson," would they know why we did that? And if they did, would they accept us as their "teacher"?

Then there's the notion of risk. "Studying risk," Vanderbilt explains," "is not rocket science; it's more complicated." And it's counterintuitive.

For instance, if our vehicles are vastly safer today than they were 40 years ago — think seat belts, anti-lock braking systems, head restraints, rear-window defoggers — why do some 40,000 Americans still die in auto crashes every year? One reason, Vanderbilt says, is that with each safety improvement — whether on our roadways or in our cars — drivers elevate their risk under the illusion that they're that much safer.

We drivers appear to be guilty of a lot of other traffic misjudgments. In one example in "Traffic: Why We Drive the Way We Do (and What It Says About Us)" the author cites a study that found that when the speed of an oncoming car is doubled, drivers turning left in front of that car estimated only a 30 percent increase. "These small discrepancies are the stuff of crashes," Vanderbilt writes.

His book, whose annotations fill 90 pages, reveals other such surprises. For example:

• People who actively look for the "best" parking spot spend more time getting to their destination from the parking lot than those who grab the first space they see.

• The optimal solution for city parking, according to one expert, is to price it so that an area's spots are only 85 percent occupied at one time, which cuts down on cruising time, and thus street traffic, and thus accidents.

• 20 mph is the fastest speed at which we drivers can make eye contact with a pedestrian — eye contact that gives us a read on the other's intentions and thus possibly preventing a fatal collision.

• Roundabouts are far safer than intersections. Intersections have, according to experts, 56 potential points of "conflict" where we can run into someone; roundabouts have 16, and they eliminate two highly dangerous moves: left turns and entering an intersection at high speed.

Vanderbilt's book will be a revelation not just to us drivers but also, one might guess, to our policy makers, including those in Washington state.

How to address a city's chronic traffic jams, for example. Vanderbilt advocates congestion pricing, which would charge drivers use of the valuable "real estate" of a roadway according to demand. The greater the demand at a given hour, the more drivers would be charged.

Surprisingly, there's no mention of the issue that's driving motorists to distraction worldwide: the price of gasoline. That's unfortunate, since gasoline's cost already appears to be affecting a range of driving issues. For instance, evidence indicates that a recent drop in U.S. traffic fatalities may result from reduced driving born of high gas prices.

That said, "Traffic" will generate new ways of approaching an issue that bedevils us all. And not incidentally, it's one more "safety feature" drivers have at their disposal, if — like a seat belt or a side-view mirror — they care to use it.