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U.S. ‘motorization’ may be in permanent decline, new study of auto use finds

A new report from the University of Michigan finds probably permanent reductions in Americans' rates of vehicle ownership, fuel consumption and miles driven per year

Americans' century-long love affair with the automobile is a many-sided and much-studied thing, and the research does not lack for complexity and contradiction.

Lately, many of the trend lines have seemed to be going down, but the reasons for those shifts are much debated — tough economic times? more telecommuting? baby boomers slowing down? twenty-somethings preferring buses and bikes? So is their likely longevity.

Sometimes data are cited that make it look like driving is still on the rise. Moreover, it can be hard to distinguish the thrust of a set of research findings from the ambitions of the sponsoring advocacy groups.

Against that background, a new report released from the University of Michigan on Tuesday stands out quite sharply. It finds probably permanent reductions in Americans' rates of vehicle ownership, fuel consumption and miles driven per year, the three components of what author Michael Sivak calls "motorization."

His analysis attributes our declining motorization to several factors, while insisting that economic conditions cannot be the primary force behind them.

And because they issue from a research program whose primary funding comes from the auto industry, which no doubt would prefer to see American motorization trending ever upward, the  findings would seem to carry additional credibility.

The study, "Has Motorization in the U.S. Peaked?" is the fifth in a series by Sivak, who holds a Ph.D. in experimental psychology and heads the Sustainable Worldwide Transportation program within the university's Transportation Research Institute.

Drawing on data from the Federal Highway Administration, the U.S. Census Bureau and ProQuest's Statistical Abstract of the United States from 1983 through 2012, Sivak shows that:

  • All three measures of motorization reached their high points between 2004 and 2008 and have been declining since then, even as the U.S. population has grown. 
  • Total fuel consumption in the light-duty (noncommercial) U.S. fleet fell 10.9% from its high point in 2004; annual miles driven fell 3.9% from the high in 2006; vehicle ownership fell 1.1% from the high in 2008.
  • Rates of motorization — fuel consumption per household, for example, or vehicle ownership per licensed driver — also have been falling, in some cases more sharply.
  • All of these declines began before the 2008 recession and have not reversed despite overall economic improvement since then.

I talked with Sivak by phone on Wednesday about the new study and other research conducted in his program that might explain the underlying shifts reflected in these trends. Excerpts from his comments follow.

Fuel consumption is down after peaking in 2003–2004.

On the overall trends

The most important finding is that there is no evidence to support the claim that maybe some of these reductions in the rates are temporary. That's the bottom line is I see it — there is no evidence that things are changing from the trend that we have observed from about 2004 on, namely a continuing decline in rates.

And I want to emphasize that I am focusing on rates, rather than the absolute numbers, for vehicle ownership, miles driven and fuel consumption.

We have an ever-growing population in the U.S., so you would expect that eventually the absolute numbers would surpass whatever peaks we had encountered in the past.

So I focus on the rates per person, per driver, per household, per vehicle — that's the interesting part, what's going on per person rather than in totality.

On economic factors

Economic contributions are clearly part of the explanation but they are not the triggering mechanism, and they are most likely not even the main reason.

If economic factors were the triggering point, the peaks would have coincided with the onset of the recession in 2007 or 2008 and I wouldn't have a story — everybody would say, this is just the economy.

And, yes, if economic forces were the primary driver for these changes, we would also have seen a uptick in the latest figures and we don't see that.

The larger factors are the ones I list in the report: more telecommuting, more use of public transportation, continuing urbanization and changes in the age composition of drivers.

On auto-averse 'millennials'

We were actually the first ones to demonstrate, several years ago, that there is a huge decrease in licensure rate for what I would call "young adults." But not just millennials: This extends from teenagers to people about 40.

Now, at the same time, there's an increase in the probability that older people will have a license. They're more likely to retain licenses than they were in the past. But they drive less, and are less likely to buy a new vehicle, and so on.

Both contribute to the overall amount of driving. But there are far fewer driver's licenses in this younger population than there were a century ago, as they reconsider their transportation options, and 22 percent of them told us they do not plan to get a license — ever.

On why nondrivers don't

We contacted 618 people, 18 through 39 years of age, who currently didn't have a license and asked them why they didn't — and more important, what their future plans were. Was this just a deferral or are they changing their way of doing things altogether?

Thirty-seven percent told us that they were too busy or didn't have enough time to get a license. Now, that is another way of saying, I have other priorities. And that is an astounding number.

Eight percent told us they are able to communicate and/or conduct business online, so part of the decline is due to virtual contact through electronic means replacing some of the need for physical contact.

Thirty-one percent indicated they could get transportation from others; 22 percent said they were able to bike or walk, so they're in a setting where they don't need to drive.

Seventeen percent said they prefer public transportation; 9 percent indicated they were concerned about the environment; 7 percent had some disability or medical or vision problems.

So it's an interesting, complex set of answers.

On whether this is U.S.-only

We've replicated the study of changes in driver licensing in 14 other countries where data was available, and many of the developed countries have similar patterns as us.

Many of the developing countries still see an increase in licensure everywhere. In China and India, I don't expect any level of saturation anytime soon.

On the other hand, in Canada and western Europe and so on, it's likely they'll continue to see the same patterns we do.

On how the news goes over in Detroit

I think people are concerned — that's the word I would use. I wouldn't say they're alarmed.

There's saving grace in that the population is still growing, so the absolute numbers of, say, vehicle purchases will eventually surpass the levels of the late 2000s. The rates are a different matter.

I truly believe there is something fundamentally going on in our society that is causing these rates to go down. I don't think the rates of vehicle use, by various measures, will ever recover to the levels we last saw in about 2004.

* * *

Sivak's new report on motorization can be read here [PDF] and links to other research produced in his program can be found here.

Comments (3)

  1. Submitted by Dennis Tester on 04/03/2014 - 09:21 am.

    Tie it to the marriage rate

    Single people can and do get by without their own vehicle quite nicely until they get married and have children. More frequent runs to the grocery store to buy multiple bags of groceries increases the likelihood that people will acquire a car.

    If you compare the reduction in “motorization” to the reduction in, or the delay of marriage, I’m guessing you’d find a correlation.

    I own three vehicles (two sedans and a truck) but put less than 2,000 miles a year on any one of them because I work from home and rarely drive more than a few miles when I do go out.

  2. Submitted by Ray Schoch on 04/03/2014 - 02:28 pm.

    Indeed, something is going on

    I can’t match Mr. Tester’s vehicle ownership or VMT (Vehicle Miles Traveled) numbers, but just from anecdotal evidence, it does appear that *something* is happening in the society regarding auto usage. He may be correct about the correlation between marriage rates and VMT.

    I used public transit far more when I lived in metro Denver than I do here in the Twin Cities. Denver’s system is quite a bit more user-friendly, and it happened that the places I wanted to go were places that public transit also served, and with some frequency. In Minneapolis, there are lots of buses in the neighborhood, but they don’t go where I want to go without several transfers – a deal-killer in this climate for about a third of the year – and I’ll be long dead before there’s a light rail or trolley system in place to take the place of the automobile in the workday rush hours after the auto reverts to its original status as something for the very wealthy.

    For many years, in both Missouri and Colorado, I averaged about 17,000 miles a year on whatever vehicle I was driving. Some of those miles were work-related in earlier decades, but I was retired throughout my tenure in Colorado, and the mileage didn’t drop, largely because “sprawl” is synonymous with the Colorado “urban corridor” along I-25. Since moving here, however, my VMT numbers have dropped precipitously, despite the fact that my Minneapolis neighborhood is completely devoid of retail development, so I must drive, almost literally, everywhere.

    I purchased a new vehicle last October – my first new car in about 19 years – and am so far averaging about 15 miles a day. If I keep that up through October, it will result in an annual total of significantly less than 6,000 miles – or about 1/3 (!!) the VMT rate I’ve been used to. A large part of that decrease (which made itself known long before the new car) is due, I think, to the combination of not having to go to work, and the relative proximity of the grandchildren. Another factor may be the relative compactness of the city and the nearby inner suburbs compared to the literal wide-open spaces along the Front Range in Colorado. When I do go shopping, most (not all, but most) of the stores I patronize are closer to me here than they were in metro Denver. I’m also making more use of online purchases here than I did in Colorado.

    So, “older driver, driving less” fits as a kind of overall stereotype, but digging a little deeper reveals a slightly more complicated reality.

  3. Submitted by beryl john-knudson on 04/04/2014 - 07:47 am.

    It’s a snow job says my Great Aunt Bertha with her conspiracy

    theories still intact, yes indeed:

    Might as well add ‘her’ ridiculous idea here…if Detroit wants to get more return for its investments at a time when mass transit becomes the jewel transportation alternative…why not make cars which will be so often recalled for ‘adjustments and put the car industry out of business (self annihilation so to speak) and thus, so successfully puts itself out of business in order to become the king of new mass transit models; designers of same working for the same automobile manufacturers that lost out for bad design in its plastic covered cars that now come with defects built in for whatever reason as mass transit buses, rail become the new transportation baby on the assembly line…aah?

    And the future looks bright for this new takeover whoever plans and ‘conspires’ to wrap whatever mode around citizen Willy or Wilma whomever, who needs to get somewhere for whatever pragmatic reason or otherwise?

    Shove it or shovel it Detroit:…now back to shoveling the god-awful white stuff I used to love in December,eh?…

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