Get me out of here!

You’ve probably heard of peak oil, and maybe even peak fish. But have you heard of “peak middle-aged people”?

That’s right: The Census projects that the aging of the baby boomers is sending the population of 45- to 54-year-olds in the United States into reverse. In fact, that age group reached its near-term peak in 2010. Even as the overall population is expected to grow, we’ll actually have fewer 45- to 54-year-olds in 2030 than we do today:

This demographic shift will almost certainly affect driving trends. According to each of the last three National Household Transportation Surveys, driving peaks in middle age. At age 54, you drive about as much as you did in your late 20s and early 30s … but after that, it’s a long, steady decline. Take a look at this chart of vehicle miles traveled (VMT) by driver age:

This makes intuitive sense: Folks in middle age are near the height of their earning power, are particularly likely to own a car, and often have demands from work or kids that boost their driving. But as people grow older, they’re more likely to retire, and less likely to have to schlep the kids to soccer practice.

But remember, the boomers are a particularly large generation — that’s why they called it a baby boom, after all — so trends among the boomers are likely to have an outsized impact on national averages. And that includes average driving.