Two new reports continue the theme that Americans are driving less due in part to Millennials not embracing cars and suburban living the way their parents and grandparents did. The first was a survey from the nonprofit Transit Center, “Who’s on Board 2014: Mobility Attitudes Survey.” They surveyed 12,000 people in 46 cities and concluded that Millennials (those between 18 and 33) are “twice as likely to take public transit” than older generations and are likely to continue doing so as they age and start families. Well, I’ve always found “revealed preference” data to be more persuasive than “stated preference” data, so let’s move on to the next report.
The Public Interest Research Group (PIRG) has just released its second report on this subject. I read the report with interest, having found their 2013 report far from persuasive. The new report seems a big more cautious in its conclusions, noting Pew’s finding that “current economic conditions can explain the more modest travel of the current millennial generation,” and noting that we will have to see what happens when economic conditions improve, a reasonable position.
Nevertheless, I see a number of methodological problems with the PIRG report. First, most of their data about how VMT relates to various factors (such as residence location, race/ethnicity, labor force participation, income, etc.) are static, generally based on the snapshot provided by the 2009 National Household Transportation Survey. That tells us nothing about changes over time.
Secondly, as I’ve seen recently in the work of other anti-auto groups, nearly all their data on vehicle miles of travel (VMT) trends ignores total VMT and focuses on VMT per capita. Just about every serious transportation researcher has acknowledged for a decade or so that per-capita VMT seems to have topped out, as it eventually had to do. According to commuting expert Alan Pisarski, the single biggest factor driving up VMT/capita over the past 30-odd years was the major movement of women into the workforce, a trend that has pretty much peaked. What is important for transportation planning is total VMT—how much demand is actually going to be placed on highways and streets. Also, PIRG’s VMT/capita graphs all extend only to 2009, when the economy was still in recession. Total VMT has turned upward again in 2012 and 2013.
Third, their VMT figures all exclude heavy trucks, yet trucks (other than personal pickup trucks) account for nearly 25% of all VMT and are critically important to highway planning. That’s because nearly all realistic projections of VMT growth show truck VMT over the next three decades growing at two to three times the rate of personal VMT. The report acknowledges this omission in one paragraph toward the end, but without providing any quantitative information. As a broad generalization, transportation researchers I’ve talked with expect total personal VMT to increase roughly in proportion to population growth and total truck VMT to grow in proportion to economic growth. That has big implications for highway (as opposed to local street) planning.
Fourth, the report says that “Available data indicate that the millennial generation is slightly more urban centric than recent prior generations,” and that “lower household formation and homeownership levels by this generation have slowed their migration to the suburbs relative to prior generations.” But are Millennials really so urban centric? How have their residential locations changed over the past decade?
Demographer Wendell Cox addressed this question, in “Where Most Millennials Are Moving; It’s Not Where You Think.” Analyzing census data, he found that there were indeed more people age 20-29 living in urban cores in 2010 than in 2000—310,000 more. But that number was dwarfed by the 1.69 million increase in Millennials living in suburbs, 620,000 more living in exurbs, and 1.82 million more living outside Metropolitan Statistical Areas. Considering only MSAs, the fraction of Millennials living in urban cores decreased between 2000 and 2010 from 20.2% to 19.3%, and the fraction living in inner suburbs declined from 46.1% to 42%. The increases were in the outer suburbs (24.4% in 2010 vs 20.6% in 2000) and exurbs (14.3% in 2010 vs. 12.2% in 2000).
In short, revealed preference data do not support the urban-centric orientation of most Millennials, and the jury is certainly still out on how their travel behavior may change as they start families and buy homes.
Robert Poole is director of transportation policy at the Reason Foundation, where this article originally appeared.
