Planners for Metro, Portland’s regional planning agency, are playing an interesting game. They did a travel survey in 1994, when gas prices were low and the economy was booming. Then they did another survey in 2011, when gas prices were high and the economy was in recession. They found that Portland travelers in 2011 are more likely to bicycle or ride transit and less likely to drive. Naturally, they credit their land-use policies with the change.
The Oregonian is rightly skeptical of the “spin” Metro planners are putting on the numbers. There are several reasons justifying such skepticism.
First, the sample size was small–4,800 people for a region of well over a million people. Second, the numbers do not tally well with the results of the Census Bureau’s American Community survey. The Metro survey found that 81 percent of Portland-area commuters rode in cars and 11 percent took transit to work in 2011. The Census Bureau, however, found that more than 84 percent drove and only 8 percent took transit in 2008. Since the census data are based on a larger sample–more than 25,000 households in Oregon, of which about a third are from the Portland area–it is probably more reliable.
Third, there’s the whole 1994 vs. 2011 comparison. Transit nationwide came pretty close to hitting bottom in 1994, when it carried only 7.9 billion trips. (Bottom came in 1995 at 7.8 billion trips.) In 2011, transit carried 10.4 billion trips, 32 percent more than in 1994. Considering population growth, this represents a 10 percent growth in per capita trips, which has more to do with gas prices than land-use planning.
Fourth, claims that density are the “key to low-car life” ignore other important differences. Planners say that auto use is lowest in the city center, which they say is denser. But the Metro survey also found that children are a major travel generator: While a two-person household makes about twice as many trips as a one-person household, a household with two children makes more than three times as many trips per day as a two-person household with no children.
What really happened in Portland is that high housing costs have driven most families with children to the suburbs, while the city center consists largely of singles and childless couples. The exodus of families with children has forced Portland to close more than a third of its high schools since 1980, and those that remain open have only about half the students that they had in 1970.
So the real key to low-car use is not density, but getting rid of the children. That’s probably not a prescription that Metro planners want to advocate out loud.