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Rush hour traffic crawls along eastbound U.S. 26 near Sylvan on Thursday. Auto sales are rebounding and peak driving times are growing more nightmarish as the economy improves. But the latest traffic and demographic data show Oregonians are driving less overall, a trend that started four years before the recession hit in 2008 and is continuing even as the economy improves. (Doug Beghtel/The Oregonian)

Northwest residents began down-shifting their driving habits years ago, with vehicle miles traveled in Oregon and Washington reaching their peak in 2004, according to traffic data.

But what about car ownership itself?

That may have also reached its apex, according to a new

.

Interestingly, despite its reputation as a multi-modal mecca for gridlock-weary commuters, Portland doesn't land in the report's top 10 cities with the lowest percentage of households that own a vehicle.

In fact, even with its superior highway system, urban sprawl and water-and-hill geographical challenges, the Seattle area continues to be the Northwest champion on that front, with nearly 17 percent of residents getting around without an automobile.

In Portland, which is 11th on the list of 30 largest cities, about 15 percent of households don't own a vehicle, an increase of less than one percent more since the last Michigan study in 2007.

"Recent studies have shown that — per person, per driver, and per household — we now have fewer light-duty vehicles, we drive each of them less, and we consume less fuel than in the past," wrote Michael Sivak, lead researcher at the University of Michigan Transportation Research Institute, in his analysis. "These trends suggest that motorization in the U.S. might have reached a peak several years ago."

Sivack examined U.S. Census and vehicle registration data.

Using the study's findings, The Atlantic's Cities blog declared: "Think cars are over in America? We do."

<a href="http://polldaddy.com/poll/7749855/">Have you changed your car ownership habits since 2007?</a>

Hogwash in the car wash.

Making such bold proclamations (researchers aren't saying that – yet) may be premature, especially when you consider that total U.S. households without a vehicle, according to the Michigan study, has hardly edged up since before the Great Recession – from 8.87 percent in 2005 to 9.22 percent in 2012.

The bottom line: More than 90 percent of American households still see the need to own a car or truck, and all of the expense and traffic jams that comes with them. That's hardly the end of car culture in America.

Even in bike-and-transit-loving Portland, there's still a passenger vehicle parked at about 85 percent of homes, or so the study suggests. That's a long way from New York City's 44 percent, as in 56 percent of households don't have cars.

In fact, as part of

, people in the Portland area are actually driving more during peak traffic hours as the economy tip toes toward recovery.

That said, research shows Americans are increasingly ditching their second and third vehicles.



Also, in the past 10 years, passenger vehicle ownership in Oregon has increased by only 4 percent, even as Oregon's driving-age population jumped 14 percent,

and

statistics show.

Still, in many areas, including the Portland suburbs, vehicle registration has grown with the population. Since 2002, for example, the number of Washington County residents has surged 16 percent to 547,672 and the number of registered passenger vehicles is up 14 percent to 418,265, suggesting that development patterns, industrial expansion and TriMet cuts in the fast-growing county have left it as car-dependent as ever.

Shifting commuting trends in Oregon's most-populous county, however, have certainly had a strong influence on statistical outcomes.

In Multnomah County, as bicycle commuting, car sharing and transit use has transpired at a revolutionary pace, the number of registered vehicles grew by less than 1 percent, even as the population grew by 11 percent.

But trends are trends.

In six of the 30 largest U.S. cities more than 30 percent of households do not have a vehicle, Sivak said. What's more, from 2007 to 2012, there was an increase in the proportion of households without a vehicle in 21 of the 30 cities.

In his report, Sivak said the continuing increases "in the proportion of households without a vehicle provides additional support for the hypothesis that motorization in the U.S. peaked during the previous decade."

-- Joseph Rose