A new study suggests sustainable city transportation declined less in the last three decades in cities based on two factors: wealthier populations as well as cities located in states that require certain planning measures.

Overall, transportation has become less sustainable across the country over this period, but some communities have slowed the decline more effectively than others.

Among the best at slowing that decline were Seattle, Las Vegas and even Los Angeles, which owes its success to fewer-than-average solo commuters and relatively high public transit use, the research suggests. In contrast, transportation sustainability declined more quickly than average over those years in such cities as Pittsburgh and New Orleans…

Could be an interesting story but I wonder if this isn’t simply masking the bigger picture: transportation sustainability is down across the board. Here is the reason why:

“Almost every city has declined in transportation ecoefficiency because we have become more automobile dependent and more spread out so people tend to have to drive farther,” said McCreery, author of the study and a postdoctoral researcher in Ohio State’s Mershon Center for International Security Studies.

People can talk about becoming gas independent to help deal with issues like high gas prices but focusing on sustainable transportation might lead in another direction: planning in such a way that people don’t have to drive as much to start with. Even though rising gas prices may lead to less driving, we still have a lot of communities that require certain amounts of driving. But, this is probably a harder sell or issue to deal with given the American love of cars, space, and local government…