Are Americans driving more or less? Does the increased popularity of walkable neighborhoods have a significant effect on driving? Or are our roads handling more traffic than ever? The measurement Vehicle Miles Traveled (VMT) helps to gauge trends in driving. VMT is tracked by the Federal Highway Administration, and data is released on a monthly basis.
It is not surprising that VMT has increased greatly over the years as the nation experienced increased suburban development, increased car ownership and a growing population. But in the 21st Century, the trends have become less clear.
Vehicle miles traveled rose steadily from 1980 to November 2007, when it started a decline that lasted 18 months. That was the longest drop the Federal Highway Administration had seen since it started keeping track in 1950, said spokesman Doug Hecox. It was a long struggle for VMT to recover, and the drop and slow return coincided approximately with the recession and slow economic recovery. VMT was fairly flat from 2010 until mid-2014.
The last big increase in VMT occurred as baby boomers came of working age.
Then in 2014, VMT increased. In 2015, a new VMT high was reached, and 2016 figures are expected to be higher still. Does that sharp increase mean that millennials have embraced the car after all?
The last big increase in VMT occurred as baby boomers came of working age and formed families, and women joined the workforce in large numbers. So are millennials taking on their parents’ habits? Few observers think so, offering other explanations for the recent rise.
Where there’s more infill and transit-oriented development, people are driving less.
“Gas prices dropped dramatically, unemployment dropped dramatically, real wages went up,” said Sam Schwartz, former New York City traffic commissioner and author of Street Sense: The Rise of Cities and the Fall of Cars. “Those are some reasons.”
Driving habits vary by community. The places that were more affected by the recession, many of them rural areas, are seeing a greater rise in VMT now, said Eric Sundquist, managing director of the State Smart Transportation Initiative at the University of Wisconsin. Where there’s more infill and transit-oriented development, people are driving less.
Per capital VMT decreased
Although total miles traveled is up, travel per person decreased from the end of 2007 until mid-2014, when it started to rise. Per capita VMT, though an imperfect measure because it counts babies and others who don’t drive, is a way to take population into account. As total VMT stayed fairly steady from 2010 to 2014, population grew, so each person was driving less. Overall, that may present a more accurate picture than just total VMT.
“Alternatively, when total VMT is up but per capita VMT is down, that could be because total VMT includes long-distance trucks, buses and other business driving that is not included in per capita VMT," said Alan Pisarski, an independent researcher who studies travel behavior.
The single largest category of increased travel in total VMT is “goods delivered,” such as Amazon Prime, said Brian Taylor, director of the Institute of Transportation Studies at UCLA.
So the increase in total VMT could be caused by more business activity. But if per capita VMT is down — and Pisarksi cautioned that we will not have meaningful per capita VMT figures for another six months to a year — it could mean that each person is driving less because there are not as many jobs as before the recession, said Pisarski. For a large sector of the population, driving is associated with work and related activities (trips to the dry cleaner, dropping off children at child care). Such employment changes may not be reflected in total VMT.”
Clearly, VMT is tied to the economy — but not as closely as it used to be, said Sundquist. For much of the 20th century, VMT grew at the same rate as the economy. That relationship started to break down in the 1990s as VMT stopped growing as quickly as the economy. But the two are still somewhat linked. With the economy still recovering, we are likely to see a continued increase in VMT, Sundquist said.
The question is whether the recent increase in VMT is a return to a long-term trend or a blip before we see VMT decline, as more baby boomers retire and millennials continue to drive less than their parents did. The question debated by developers, planners, automakers and others is, what will millennials do when more of them have families?
Millennials’ driving habits
The NATIONAL ASSOCIATION OF REALTORS® and Portland State University did a survey of different age groups with and without children at home. For millennials with children in the household, the survey found no significant difference in the share that chose an attached home in a walkable community or a detached home that required more driving. For members of Generation X (those born from 1965 to 1980), only 40 percent of those with kids chose an attached walkable home vs. 49 percent who had no children at home.
Millennials have stayed with their preference for attached walkable homes, even as they have formed families.
Those figures would seem to indicate that so far, at least, millennials have stayed with their preference for attached walkable homes, even as they have formed families.
“Are they going to be just like previous generations — move to the suburbs, get station wagons and a garage and drive everywhere?” said Chris Zimmerman, vice president for economic development at Smart Growth America. “No, because they have fewer kids and they have them later.”
“Younger people have chosen more urban lifestyles. They don’t necessarily want to give it up and move to the suburbs. The market has shown they clearly don’t want that.”
Sundquist agreed. Millennials are driving less at their current average age of 30 than baby boomers or Gen Xers were at that age.
“The mindset is different now,” Sundquist said. “They’re not as afraid of transit; it’s not a foreign concept. Cities are more livable now, crime rates are lower.” It’s not just a choice between driving everywhere or not owning a car at all. A family could decide to have one car instead of two.
But Taylor of UCLA was part of a large study for the Federal Highway Administration on millennials’ travel behavior from 1990 to 2010 that reached a different conclusion. Although it’s true that millennials are driving less than previous generations were at the same age, the study looked at markers of adulthood instead of age. Those include paying their own bills, finding a partner, having a child and buying a home. In the past 25 years, those rites of passage have stretched out so that people are marrying and having children much later.
The study found that once those adult markers have been reached, millennials drive as much as previous generations. The decline in VMT during the recession was mostly caused by economic circumstances, Taylor said. The group of millennials Taylor calls multimodals — more likely to live in more urban environments, relatively well educated, with access to cars, but also likely to travel by walking, biking or transit — increased by 50 percent between 1990 and 2010.
The majority of millennials live in the suburbs and drive to work.
That’s a large proportional growth, but their share of all millennials went from only 3 percent to 4.5 percent.
The vast majority of millennials, said Taylor, live in the suburbs and drive to work. When VMT decreased, it was not because the average person drove less, but because the types of travelers shifted. At the end of the period studied, in 2010, there were more multimodals and more carless young people. The carless were more likely to be unemployed and struggling economically. Their carless lifestyle was not a choice.
“The vast majority of young travelers travel almost exclusively by automobile,” said the report Taylor helped write for the Federal Highway Administration. That’s probably because most millennials, like most Americans, live in the suburbs. Just 4 percent of urban neighborhoods have more travel by foot and transit than by car.
Undersupply of urban housing
But as Smart Growth America’s Zimmerman points out, most Americans live in the suburbs because there’s an oversupply of housing there and a very limited supply downtown. Housing is now cheaper in most suburbs after the policies of the past 50 years, followed by changing consumer preferences, created a glut.
There are more people who want to live in a place where they can walk to their daily needs than have it, Zimmerman said. “It takes a long time for the housing supply to catch up.”
The undersupply of urban housing is partly driven by policy. “Much of city zoning requires single family housing,” said Todd Litman of the Victoria Transport Policy Institute. “Until that’s corrected and zoning codes are more flexible, people will be fighting over that limited option.
“Whether in the future there’s going to be more driving depends on [cities and their zoning codes]. Cities are growing faster than suburbs. The basic trend is there. Now we are failing to provide affordable housing in walkable neighborhoods.”
Litman has found what he called a “latent demand for living in a more multimodal neighborhood. If you ask, ‘Would you rather drive less and rely more on walking, biking and public transit?,’ most Americans would prefer to reduce their driving, provided their alternatives are good.”
It’s not just a matter of everyone wanting to live downtown. All types of neighborhoods are affected by changing consumer demands. “An increasing portion of the suburbs are redesigning themselves so they do have some mixedused walkable neighborhoods,” said Litman.
Smaller cities are joining the trend. Schwartz, who runs a transportation planning firm, Sam Schwartz Engineering, said, “We’re traveling to places we’ve never been invited before.” In cities like Los Angeles, Tampa, Boise and Grand Rapids, a lot of young people don’t want to own a car. They have a host of options their parents did not in the sprawling suburbs — ride-hailing services like Uber, public transit, walking and biking. For housing and transportation planners, all eyes are once again on the millennials.