Just how stupid is the TTI Urban Mobility Report?
CEOs for Cities says that the annual Texas Transportation Institute report, released January 20, "remains a flawed and misleading guide to urban transportation."
In a report released last October called Driven Apart, Portland economist Joe Cortright made a compelling case that TTI's methods make little sense as a guide and review of true mobility of US metropolitan transportation systems. The highly influential TTI report ranks the congestion of highway systems around the country and gets a lot of media attention.
As Streetsblog puts it: "The most regrettable thing about TTI’s rankings is that they will be used to justify highway projects around the country, which will actually cause people to spend more time driving as a result of the accompanying auto-sprawl."
The Smart Growth blogosphere is all over this story. Greater Greater Washington's David Alpert probably offered the best explanation of why the report is flawed:
"Consider two hypothetical cities. In Denseopolis, people live within 2 miles of work on average, but the roads are fairly clogged and drivers can only go about 20 miles per hour. However, it only takes an average of 6 minutes to get to work, which isn’t bad.
"On the other hand, in Sprawlville, people live about 30 miles from work on average, but there are lots and lots of fast-moving freeways, so people can drive 60 mph. That means it takes 30 minutes to get to work.
"Which city is more congested? By TTI’s methods, it’s Denseopolis. But it’s the people of Sprawlville who spend more time commuting, and thus have less time to be with their families and for recreation."