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.