Above 55, the story’s a little different. Older adults were more likely to have a driver’s license in 2014 than in 1983—in the case of those 70 and older, 43.6 percent more likely. But these age groups, too, saw a modest decline from 2011 to 2014.

The researchers didn’t look into what the reasons for this decline might be, but in an earlier study, they surveyed young adults ages 18 to 39 without driver’s licenses about why they don’t have them. The top three reasons were: “too busy or not enough time to get a driver’s license” (37 percent), “owning and maintaining a vehicle is too expensive”(32 percent), and “able to get transportation from others” (31 percent).

Another reason that springs to mind is that more people are living in cities and using public transportation. But in the survey, only 17 percent said their reason for not having a license was that they preferred public transit.

In other studies, Sivak and Schoettle suggest that driving in general may have already peaked in the United States. The total distance driven per person in the U.S. was at its highest in 2004, and by 2013, it had decreased by 9 percent. In part, this may be because people are traveling less in general: Comparing 2004 to 2014, people spent less time traveling to places to eat and drink, to buy goods and services, to work, school, and to leisure activities. The ease of Amazon, the rise of teleworking, and the endless entertainment provided by the Internet may be leading people to stay home more, but it’s hard to say—there’s no research available that explains these trends. A New York Times article from 2013 mentions unemployment as a reason for young people buying fewer cars, but as Jordan Weissman noted in The Atlantic that same year, downward trends in driving started before the recession.

Maybe it’s just that people today have more things they’d rather do than practice parallel parking between traffic cones. Or maybe it’s because the photos on those plastic cards are almost never flattering. Sivak and Schoettle are hoping to soon study possible reasons for the drop in driver’s licenses. But regardless of the cause, it seems that if you want to insult a teen today, shaming them for not being able to operate a motor vehicle might not be the way to go.