I just finished listening to Traffic: Why We Drive the Way We Do , appropriately enough, while driving around Boston. The book is probably better read/skimmed than listened to, and/or needs abridgment. There are some worthwhile nuggets of information, however, and I’ve selected a few below.

SUVs are hugely costly to society. Because they are long and sluggish, they spend much more time getting rolling from a stop at a red light. This is one reason that our city traffic has slowed down. SUV drivers sit higher from the optical rush of the road so they are more likely to speed (just as you wouldn’t have a strong sensation of speed in an airplane 1000′ above the ground, though the airplane is moving at 4X the speed of a car). SUV drivers in at least two countries studied are less likely to wear seatbelts, more likely to be talking on a mobile phone, and less likely to have both hands on the wheel. They crash constantly and are statistically less safe than a minivan that is lighter weight.

Low-cost parking meters in cities are a primary cause of traffic jams and accidents. About 12 percent of cars driving around a city are looking for a parking spot. Those folks drive very slowly. When they stop, they tend to get hit by other cars, and traffic comes to a standstill until the accident is cleared. As soon as parking spots are more than 80 percent occupied, city traffic slows down to a crawl. (If we had a nationwide wireless Internet and perhaps an RFID transponder in cars, the solution would presumably be dynamic pricing for parking spaces so that there were always about 20 percent free.)

Intersections with lights are hugely dangerous and have very little capacity compared to roundabouts. The heavyweight control systems and signs don’t ensure driver or pedestrian safety. The intersection is useless during a clearing phase that has to be lengthened every year (now it is about 2 seconds of red in all directions). The intersection is very slow to start up again after a red (see the note about ponderous SUVs above).

Signs are basically useless, especially as they have been layered onto our roads year after year. People drive slower around curves with no “curve warning 30 mph” sign than they do with the sign. Deer crossing signs do nothing to reduce the prevalence of deer-car collisions.

High curbs and crosswalks do not protect pedestrians. In fact, in Dutch cities where all signs, curbs, and markings have been removed, accidents and injuries have gone down. Traffic engineers have spent decades applying techniques that work on highways to city streets and continue doing so though all research shows it doesn’t work. All of the road engineering discourages drivers from paying attention to what is happening around them. [Similar results were found in London.]

Skill does not make for a safer driver; an insurance company study of NASCAR-style racing drivers found that these supremely skilled individuals were more likely to get into accidents when driving on public streets than the average driver.

Contrary to advertisements touting the miracles of airbags, new cars are no safer than old cars, according to studies in Norway and the U.S. Adjusted for miles driven, people in new cars are more likely to be in an accident and more likely to be injured than people in old cars. Quite a few people are killed in new cars while traveling at less than 35 mph. What would reduce deaths and the cost of injuries would be if everyone wore helmets, though this has never been seriously proposed.

I recommend the book in print because each section stands on its own nicely and the reader can pick and choose the most interesting topics.