Traffic

by Tom Vanderbilt

These are places where the car is meant to be a guest, not the sole inhabitant.

Yet the traffic engineers, argued Monderman, with their standardized signs and markings, have forced the traffic world upon the social world.

The more stop signs, the more likely drivers are to violate them.

Rather than hit people over the head with speed bumps they would resent and signs they would ignore, better results could be achieved if drivers were not actually aware that they were slowing down, or why. “Mental speed bumps” is the delightful phrase used by David Engwicht,

Traffic signals assign priority; they do not provide safety.

Careful jaywalking, particularly on one-way streets, can be safer than confident crossing at the crosswalk (where the pedestrian may have to worry about streams of traffic from different directions). A similar phenomenon seems to occur at the crosswalks one finds at places without traffic signals.

people at unmarked crosswalks tended to look both ways more often, waited more often for gaps in traffic, and crossed the road more quickly.

Rather, the uncertainty of the space and its human-scaled geometry dictate the behavior.

A Florida study found that a pedestrian struck by a car moving 36 to 45 miles per hour was almost twice as likely to be killed than one struck by a car moving 31 to 35 miles per hour, and almost four times as likely as one struck by a car moving 26 to 30 miles per hour.

“Horn Please” originally invited following drivers to honk if they wanted to pass the slower-moving, lane-hogging trucks on the narrower roads of the past, and I was told that it endures merely as a decorative tradition.

They provide “intrigue and uncertainty,” as Engwicht put it, and the average Delhi driver would certainly rather be late for work than hit a cow.

“Good brakes, good horn, good luck.”

traffic culture. This is how people drive, how people cross the street, how power relations are made manifest in those interactions, what sorts of patterns emerge from the traffic. Traffic is a sort of secret window onto the inner heart of a place, a form of cultural expression as vital as language, dress, or music.

astute drivers will echo local inflections like the “Pittsburgh left,” that act of driving practiced primarily in the Steel City (but also Beijing) in which the change of a traffic light to green is an “unofficial” signal for a left-turning driver to quickly bolt across the oncoming traffic. New arrivals to Los Angeles soon become versed in the “California roll,” a.k.a. the “sushi stop,” which involves never quite coming to a complete halt at a stop sign.

yesss! he finally mentions the pittsburgh left

Cialdini argues there are two different norms at work: an “injunctive norm,” or the idea of what people should do (the “ought” norm), and a “descriptive norm,” or what people actually do (the “is” norm). While injunctive norms can have an impact, it was the descriptive norm that was clearly guiding behavior here: People littered if it seemed like most other people did. If only one person was seen littering in a clean garage, people were less likely to litter—perhaps because the other’s act was so clearly violating the injunctive norm.

Studies have shown that the less densely populated a place, the higher the risk of traffic fatalities.

The nonfatal crash rate, on the other hand, is usually higher in more densely populated places: There are more people to run into.

In an average year, more people were killed in the United States on Saturday and Sunday from midnight to three a.m. than all those who were killed from midnight to three a.m. the rest of the week. In other words, just two nights accounted for a majority of the week’s deaths in that time period.

The morning rush hour in the United States is twice as safe as the evening rush hour, in terms of fatal and nonfatal crashes.

The most important risk factor, one that is subtly implicated in all the others, is speed. In a crash, the risk of dying rises with speed. This is common sense, and has been demonstrated in any number of studies. In a crash at 50 miles per hour, you’re fifteen times more likely to die than in a crash at 25 miles per hour—not twice as likely, as you might innocently expect from the doubling of the speed.19 The relationships are not proportional but exponential: Risk begins to accelerate much faster than speed. A crash when you’re driving 35 miles per hour causes a third more frontal damage than one where you’re doing 30 miles per hour.

According to estimates by researchers at Carnegie Mellon University, men die at the rate of 1.3 deaths per 100 million miles; for women the rate is .73. Men die at the rate of 14.51 deaths per 100 million trips, while for women it is 6.55. And crucially, men face .70 deaths per 100 million minutes, while for women the rate is .36.38 It may be true that men drive more, and drive for longer periods when they do drive, but this does not change the fact that for each minute they’re on the road, each mile they drive, and each trip they take, they are more likely to be killed—and to kill others—than women.

Teens are less likely to be wearing seat belts and more likely to be drinking when driving when there are passengers in the car.47 Many studies have found that teen drivers are more likely to crash with passengers onboard,48 which is why, in many places, teens are restricted from carrying passengers of their own age during their first few years of driving.

Rural, noninterstate roads have a death rate more than two and half times higher than all other roads—even after adjusting for the fewer vehicles found on rural roads.52 Taking a curve on a rural, noninterstate road is more than six times as dangerous as doing so on any other road.

the safer cars get, the more risks drivers choose to take.

Helmets, cheaper and more reliable than side-impact air bags, would reduce injuries and cut fatalities by some 25 percent.

During snowstorms, the number of collisions, relative to those on clear days, goes up, but the number of fatal crashes goes down.

half of all traffic fatalities to seat-belt-wearing drivers in frontal collisions happen at impact speeds at or below the seemingly slow level of 35 miles per hour.

As one study found, “there is a systematic and reliable tendency for [drivers] to follow their direction of gaze with their direction of travel, in many cases without the conscious awareness of doing so at all.”