Mary Roach gleans these nuggets in her review of a new book on traffic:
- 12.7 percent of the traffic slowdown after a crash has nothing to do with wreckage blocking lanes; it’s caused by gawkers.
- In a study of one 15-block area near U.C.L.A., cars were logging, on an average day, 3,600 miles in pursuit of a place to park.
- The Hebrew calendar is programmed into about 75 signal lights in Los Angeles. This is done to enable Sabbath-observant Jews to cross the street without pushing a button and violating the ban on operating machinery.
- Nearly 80 percent of crashes involve drivers not paying attention for up to three seconds. Thus the places that seem the most dangerous — narrow roads, hairpin turns — are rarely where people mess up. “Most crashes,” Vanderbilt writes, “happen on dry roads, on clear, sunny days, to sober drivers.” For this reason, roads that could be straight are often constructed with curves — simply to keep drivers on the ball.
- A study that followed 24 intersections that had been converted from signals or stop signs to roundabouts showed an almost 90 percent drop in fatal crashes after the change.
- For similar reasons, S.U.V.’s are more dangerous than cars. Not just because they’re slower to stop and harder to maneuver, but because — by conferring a sense of safety — they invite careless behavior. “The safer cars get,” Vanderbilt says, “the more risks drivers choose to take.”