What's the Driving Force Behind Less Driving?

Last time, I showed you evidence (courtesy of Robert Puentes and Adie Tomer of the Brookings Institution and Adam Millard-Ball and Lee Schipper of Stanford University) that driving per person seems to have peaked in the 2000s and now may even be dropping. This bucks every travel trend we’ve seen since Henry Ford got to work. What might be slowing down the acceleration in driving?

Are higher fuel prices to blame? Perhaps in part. There is some debate on the magnitude of the effect gas prices have on fuel consumption, but luckily you don’t have to throw out your basic economics textbook; people do drive less when the price of driving rises. A fairly recent study by economists Kenneth Small and Kurt van Dender found that a 10 percent increase in gas prices leads to a 0.2. to 0.3 percent reduction in driving in the short run, and an eventual reduction of 1.1 to 1.5 percent.

But does this explain the driving slowdown? Maybe partially, but not entirely. The growth of driving began to abate around 2000, and driving flattened out around 2004; the big gas price hikes didn’t come until late in the decade. Besides, though the graph I showed you last time has a couple of kinks in the 1970s, the relentless rise in driving basically shrugged off a comparable (in real terms) runup in oil prices during that decade.

Does the travel plateau have to do with government policy? For example, are our rising expenditures on public transportation getting people out from behind the wheel? The answer is no. Despite decades of rising spending on mass transit, transit travel has remained stubbornly flat. According to the American Public Transportation Association, in 2008 total transit ridership was actually below 2000 levels, despite growth in the population and economy.

Nor was government responsible for any big increases in America’s (disappointingly low, in my humble opinion) gas taxes during the period in question.

What about the land use policies favored by many urban planners, which are supposed to be reducing trip lengths by bringing origins (homes) and destinations (work, school, shopping) closer together? If they are having any effect, it is not showing up in the overall statistics. According to the National Household Travel Survey, the average vehicle trip rose from 9.0 to 10.1 miles between 1990 and 2009, and the average work trip rose from 11.0 miles to 13.7. If land use changes are at work, these numbers should be falling, not rising.

It is true that other countries Millard-Ball and Schipper studied – Australia, Japan, the U.K., Sweden, Australia and Canada – do have more anti-car policies, and considerably lower levels of driving, than we do. (The Japanese drive about 40 percent of the miles per person that we do, while at the other end of the spectrum Australians and Canadians drive about 67 percent as much.)

A lot (though probably not all) of the cross-national differences in vehicle miles traveled may indeed be attributable to government policies, including restrictions on parking, high gas taxes, stiffer registration fees, higher minimum driving ages, land use policies that promote density, more spending on transit, etc.

But fascinatingly, the slowdown in driving is evident in all of those countries, and it started at about the same time ours did. Since there was no coordinated push toward anti-car policies in the 2000s, it is hard to maintain that government is fundamentally responsible for what seems to be a trend across the developed world.

Is peak travel due to stagnant incomes? As my mentor, UCLA’s Brian Taylor, has pointed out, driving and economic health go hand in hand. To be sure, differences in national wealth probably explain a lot of the residual difference (not accounted for by policy) between driving in other developed nations and driving here. And right now we are, of course, finally waking up from a doozy of a recession, which is almost certainly having an effect on travel patterns.

However, the VMT plateau predates the financial crisis by years. As Millard-Ball and Schipper note, auto use flattened even as GDP grew in the late 1990s and early 2000s, both here and in other developed countries. Thus the link between rising wealth and rising VMT may have finally been broken.

Are there any more promising explanations? Next time I’ll outline some.


Jobs are moving to office buildings and industrial parks in the suburbs.

Early growth in driving occurred as people moved to the suburbs and commuted to jobs that remained in "the city" for all the reasons that "the city" grew up in the first place.

Businesses now find no need to remain crowded together in expensive central office towers so they are moving out to the lands of freeway interchanges, free parking, high quality city services, low crime and high quality labor.

Dan F.

I can't speak for anyone else, and of course the plural of anecdote is not data, but I can tell you my experience:

I'm 32, and when I purchased my home, I made an effort to find a location near to public transit, and shortly after I moved in, also found a job right across the street. Even with the same pay (normally I would only have changed jobs for a raise) the idea of not needing to drive to work became like a raise to me, because I didn't need to spend the time or money on my car, and eventually sold it. Now I even rent out my parking spot at home, so the effective increase in my take-home pay is nearly $10k/year based on not needing to drive to work (Including gas, parking maintenance, depreciation, etc). Not even accounting for the time savings of not needing to commute, which at my hourly rate is another 10k/year.

The question is, are people just realizing this? or are more people working from home or are there more residental units located near work locations now?


Jonathan Bagley

In the UK I'd say congestion and more enforcement of speed limits. Driving no longer a pleasure. Less "going out for a drive." Perhaps car parking charges and drink-drive law enforcement. More stigma attached to drink-driving.


The timeframe here is particularly amusing to me, as it happens to coincide perfectly with when I began telecommuting full time, so my annual mileage decreased dramatically starting in 2000 and has remained lower ever since that professional adjustment.


and to piggyback on my prior comment, 2004 is when my wife began to telecommute, so her commute became 0 miles as well.

To me, the answer seems straight forward, never before have we had so many people in the workforce that work from home on a consistent basis.


How do longer trips play into the stats? Meaning, has there been any difference in the changes of number/length of shorter trips (say less than 50 miles) versus longer vacation-type trips (say over 100 miles)? I'd be interested to see how a decline in vehicle miles corresponds to airline miles flown. I think the early 2000's was when vacation travel by plane started to get relatively cheaper (could be way off on this, just a feel), so possibly roadtrips were replaced with flights, thereby reducing miles traveled.


My guess is that young people aren't able to justify the expense of car ownership given their incomes and other spending needs.

More and more college graduates seem to be moving to big cities, where housing prices are still very high relative to incomes. Big cities have better public transportation networks and higher car ownership costs, particularly for parking. Student loans are more common than ever, and more students are deeper in debt, which means bigger monthly payments. All of these factors discourage car ownership.

Christopher Zibailo

It would seem pretty likely that we have more people living in cities with robust telecommunications services that make it easy to stay at home, hence less driving.

With an online account Peapod delivers your food, Dining-In delivers your dinner, Netflix delivers your movie and you never leave the house. For work, I work from home in my PJs two days a week and most people have no idea I am not in the office, with my VoIP service. And rather than driving 300 miles a week to go to appointments I spend a lot of time on conference calls and giving Webinars from the comfort of my own home.

And my now retired mom brags about how she didn't have to go to a single store to do Christmas shopping because she does everything online.

Brian Potter

I think many of the posts on the increase in telecommuting are on target, but I think comment #5 from "D" is most to the point. Technology has moved work and play to the internet, and so we go out less. I watch my teen age son and the youth I work with "get together" several nights each week via the web. In contrast, I grew up cruising town every night - an ungodly number of miles, I'm sure!

Ian Kemmish

Does the phrase "milking it" mean anything to the author? This seems an object lesson in stretching the content of a single column out to (at least) three. And presumably getting paid three times.

Perhaps the true conclusion we should come to is that paying economists by volume is a Bad Thing....


In Portland, OR, one statistic says that more people ride bikes to work than take public transportation. So, that is a lot of cars off the road.

As a retired person, I drive much less, partly because all of the bicycle riders make me nervous, as they dart in and out of traffic. So, I walk or take the bus.


You need to go back to your oil price histories. "The growth of driving began to abate around 2000, and driving flattened out around 2004; the big gas price hikes didn't come until late in the decade. " - does not match the history.

Oil prices reached a low of around $10 per barrel at the end of 1998/early 1999. By late 2000, the oil price per barrel had tripled to around $30 per barrel. The internet bubble recession caused prices to briefly fall again to the upper teens by late 2001, but then rise fairly relentlessly until the housing bubble popped in 2008. You can see the numbers at the EIA website here: http://www.eia.doe.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=WTOTWORLD&f=W

Going back to your narrative, travel started to decline, worldwide, right along with oil prices rising, also worldwide. I suspect once you get the oil price history right, more of this will be explained by rising oil prices.



Are higher fuel prices to blame?


Why are we *blaming* anything for decreasing our dependence on fossil fuel?


Add another vote for telecommuting as a big factor. A decade ago I used to drive about 30 miles (round trip) every working day, now I take a few steps from kitchen to office.

That has some ripple effects, too: because I no longer have to maintain much of a "professional" wardrobe, I can do most of my clothes shopping with a couple of trips a year to REI, supplemented with on-line ordering from LL Bean &c.


I vote that the biggest factor is significantly improved telecommunications and consumer electronics. I often enjoy the comfort of my own home when watching a movie or shopping more than driving to a movie theater or mall. Additionally, I am more likely to invite friends over to my house, which means that instead of everyone driving to a separate location, I am not driving at all, reducing our collective driving by 10%.


In addition to the rise in telecommuting and on-line shopping, attitudes toward driving may have been different among those who are now aging and therefore driving less. Not just environmental awareness, but whether they enjoyed driving. I know my parents (now in their late 70's) seemed to think of driving around and looking at things as a hobby, it was something they did for fun. I can't say I've ever thought that, even when I was a kid being schlepped around in the car. I've always seen driving as a chore, never as a pleasure.

Dave Hurst

Try correlating the drop in driving with the implementation of corporate VPN networks (which suddenly appeared almost ubiquitously in the early 2000's) and increased bandwidth (i.e. 'WebEx' and the like). We're driving, and travelling less, because our physical presence is not required as often.

[Working from home today]

E Olson

Could the VPM be linked to the use of the VPN? That bit ot technology is worldwide.


But, but, but... driving is cheaper than ever now. gas is expensive but not compared to in creased incomes.

Cars are expensive, but much more reliable and durable.
10,000 miles between oil changes.

I think jobs moving to the suburbs makes sense, as a reason.


I think this is more than one causality, we have multiple population trends that started allowing lowering trends. super-stores became prevelent in suburban areas reducing errand travels, moving closer to work, higher efficiency vehicles, and aging populace that definitely drive less and acutally retire to self-contained comunities. Since the first baby-boomers reached 66 this year, you might even see a higher reduction in travel as they start to retire, in fact, I bet, that as the economy rebounds many will start to retire, so watch for nation wealth increases to accelerate the reduction in miles travelled.