September 19, 2012 Liz Borkowski, MPH 4Comment

The New York Times has a terrific graphic that plots the number of auto fatalities per 100,000 people and the vehicle miles driven per capita from 1950 to 2011. Overall, we’re driving far more vehicle-miles per capita and seeing far fewer auto deaths than we were six decades ago, but this hasn’t happened in a linear fashion. Rather, as Hannah Fairfield explains, change occurs unevenly:

Plotting the two most important variables against each other — miles traveled versus deaths per 100,000 population — yields a pattern that looks like a plateau followed by a steep drop. It evokes the theory of punctuated equilibrium, proposed by the paleontologists Stephen Jay Gould and Niles Eldredge, which suggests that instead of continuous gradual evolution, change occurs abruptly after periods of virtual standstill.

Technologies like antilock brakes and airbags help reduce fatalities, as do behaviors like increased seatbelt use and reduced drunk driving. Disruptions to oil supplies in the 1970s and the recent recession reduce vehicle-miles per capita (temporarily, in the case of the 1970s), and per-capita fatalities fall at the same time. In short, we can reduce auto fatalities by driving less; driving more safely; and having vehicles that make crashes less likely to kill.

I can think of a few trends that are likely to influence per-capita auto fatality rates over the next few years. For overall vehicle miles traveled (VMT), a combination of high gas prices and continued high unemployment rates might keep driving from increasing too much. As The Atlantic Cities’ Nate Berg points out, higher gas prices aren’t the only route to lower VMT — increasing smart growth (by allowing greater housing density, investing in public transit infrastructure, etc.) can also reduce per-capita driving. As we’ve noted before, investing in public transportation and making streets friendly to pedestrians and cyclists can advance public health in multiple ways: by increasing mobility for those who can’t drive, allowing more opportunities for physical activity, and decreasing air pollution, as well as reducing traffic fatalities. (And as I’ve also said before, advocating for transit/pedestrian/bike improvements is not the same as saying everyone needs to stop driving — the point is to increase options, and assume that people will choose different modes depending on circumstances.)

In terms of behavior, the increased use of cell phones while driving is a definite hazard. Though many states have laws against texting and/or using handheld phones while driving, I’m skeptical about how much that’s done to change behavior. The Department of Transportation, National Highway Traffic Safety Administration, and Occupational Safety and Health Administration have campaigns against distracted driving. OSHA tells employers:

It is your responsibility and legal obligation to create and maintain a safe and healthful workplace, and that would include having a clear, unequivocal and enforced policy against the hazard of texting while driving. Companies are in violation of the Occupational Safety and Health Act if, by policy or practice, they require texting while driving, or create incentives that encourage or condone it, or they structure work so that texting is a practical necessity for workers to carry out their job.

We should also remember that fatality statistics don’t tell the whole story. Thousands of people are severely injured in vehicle crashes each year (and a significant portion are pedestrians or cyclists struck by vehicles). We’re fortunate that technology improvements like airbags have made crashes less deadly, but we should keep striving to prevent crashes from happening in the first place.

4 thoughts on “Technology, behavior, and reduced driving associated with decline in auto fatalities

  1. Although the uptick from 92-95 is attributed to SUV popularity, I don’t see an uptick after 2000 for cell phone use. I don’t deny phones/gps are bad distractions, I was surprised not to see it in this data. It may be part of the plateau from 2000-2004, but efforts to curb cell phone use seems to me to be mostly in the last 4 years.

    I guess car safety features outpaced cell phone adoption?

  2. Actually it did happen in an almost linear fashion. NYT’s odd (but certainly dramatic) choice of fatalities per capita makes it difficult to deconvolve fatalities from the number of miles driven. A graph of fatalities per Vehicle Miles Traveled shows a much more regular decrease with just a few minor humps between 1966 (the peak) and now. The most notable features are the decrease at 1973 ( national 55MPH limit), a small hump at 1980, and a steep decrease from 1981-83. The first federal standards for crash tests were in ’81 …

  3. @ Thad, @Liz: add the increase in cupholders to the risk column as well. I was rear ended earlier this year by a (very honest and apologetic) woman who dropped her water bottle and leaned over to pick it up.
    I was fine, but her air bag broke her arm against her windshield.

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