Plenty of national news stories have noted the recent nose-dive in driving all across the United States. Federal figures show that over the past year—as gas prices spiked and the economy slumped—total vehicle travel fell more 3 percent, a remarkable decline.
But it’s a bit more surprising, perhaps, to find that there’s been a decline in per-capita vehicle travel in the Northwest states—Oregon, Idaho, and Washington—that’s has been underway for nearly a decade.
Take a look at the chart to the right. It shows vehicle travel from the Federal Highway Statistics reports, adjusted for population, from 1994 through 2007. And as you can see, per-person vehicle travel has been on the decline since 1999, back when gas prices were at historic lows. When 2008 data are released, I expect that we’ll see even steeper declines.
To me, the interesting thing is that the falloff in per-person vehicle travel has been slow and steady: nothing big in any one year, and not enough to make headlines, but enough over time to make a difference in our per-person travel. In fact, the per-capita declines over the past few years have nearly offset population growth: total vehicle travel in the Northwest states was only a wee bit more in 2007 than it was in 2003.
Two quick caveats about the numbers.
First, VMT data tend to be a bit dicey, since they’re based on modeling estimates from a relatively small set of samples—basically, those “tube counters” you sometimes drive over on the highway.
And second, most of the decline is the result of Oregon’s trends! Driving’s dipped a bit in both Washington and Idaho, but Oregon has led the way, with a 9 percent decline in per-capita mileage between 1999 and 2007. This makes me wonder whether Oregon’s doing something right—or if the Federal data are simply a bit screwy!!
Frank
I’d guess a big chunk of it has to do with growth management and the increased urbanization of those states. As new urbanites move in (who are either carless or near-carless), they push the per-capita VMT down for the whole region, even if everyone else’s driving stays constant.
ml johnstone
I’d like to see that line go down to almost 0.
erin
i would like to add one more potential caveat: changes in the overall age of the demographic sampled. even as the ‘baby boom’ generation led way to the next, as a u.s. population, our birth rates have been in steady decline. that means with a ~16 year time lag, the number of drivers will be (and is also currently) in decline. that means the decline could just be due to population numbers and not be indicative of a downward trend in driving. instead of miles driven per capita, i would like to see the statistics for but miles driven per capita of those over 16-years of age
Matt Leber
I grew up in Seattle and remember driving EVERYWHERE. I used to not think twice of driving from Seattle up to Mountlake Terrace or out to Issaquah to take in dinner and a movie. Traffic being what it is today, I’m far more hesitant to take on long unnecessary trips like this. It would be interesting to see this graph along with a graph of average travel times per mile or something like it. ???
morgan
In Clark’s graph, where data points are 12months apart, 1999 is the highpoint of VMT consumption. This would seem to conform to existing conceptions about how people decide to drive or not—“historically low prices lead to historically high per capita VMT”. Such conceptions would predict that per capita VMT falls off following a period of record low fuel prices. Following the very low prices during the winter of 98-99 (down 20 cents-ish), prices were right back up by the summer of 99 and didn’t relent until this past September. Conventional wisdom would again suggest that rising prices place downward pressure on per capita VMT during this period. So, I’m not really sure what Clark is finding interesting or odd, at least within the bounds of my points. More broadly, I think it’s important to also consider how fuel prices reflect VMT consumption/demand rather than just how prices drive said demand. I’m no fuels expert by any measure, but I’d be shocked to learn that the recent plummeting in fuel prices was not strongly influenced by reduced demand/employment. Early 01 was when unemployment shot up from 4% nationally to almost 6% by the end of the year and stayed high until 07. When people aren’t working, they aren’t commuting and aren’t buying fuel.I’d also direct attention to the influence of congestion of travel decisions. The costs of congestion for every driver are usually orders of magnitude higher than rises in fuel prices. Let’s see—if I value my time say a paltry $10/hr (which is what the SR167 HOT lane study showed, maybe it was even lower), a 3 minute increase in my commute each way equals $1/gal increase for a typical car commuting 12.5miles each way. Now think about what a rational person valuing their time at $30/hr decides. You can bet they will combine and avoid trips.So, considering the soft economy during the opening years of the century, record high nominal prices (like the price of milk, this is what people notice) for the past 10 years, growing congestion and ongoing urban-migration, I find there’s all kinds of reasons to look for falling VMT—except for those pesky agency projections based upon deep historical trends. my apologies for the length, between the coffee and lack of editing time…….
passionfruital
I’m curious how these statistics compare with other regions in the U.S.