Chicago Circle Interchange


You probably saw the thing about the Circle Interchange being the worst in the nation for truck drivers. It's one of several prestigous awards it's won recently, placing third in an 2002 USDOT ranking of the worst bottlenecks in the U.S. (and it doesn't even have a good nickname like the "Hillside Strangler," which you probably know, or Dallas's "Mixmaster," which is an awesome name), and a place in Popular Mechanics' list of 10 Pieces of U.S. Infrastructure We Must Fix Now.

But on the whole, maybe it's not so bad. Last year's study "Driven Apart," still a hot topic in transportation circles, compares different U.S. metropolitan areas and finds that Chicago's auto commute is the best. Really!

I wouldn't go so far as the description on the otherwise excellent graphic does: "what creates traffic jams isn't more cars and fewer highways, it's sprawl." Actually looking at the results, a more accurate assessment seems to be that different cities have different traffic problems. Commute times in San Francisco, New York, and Miami are bad, but sprawl only adds a small part of that. Commute times in Richmond and Kansas City are good, but sprawl adds a great deal to them. Chicago, somehow, maintains a good balance.

The CEOs for Cities/Rockefeller Foundation report is in marked contrast to the Urban Mobility Report out of Texas A&M, which Jon Hilkevitch wrote about yesterday in the Tribune, and which found:

Rush-hour drivers in the greater Chicago area paid the highest congestion penalty in the U.S. again last year, averaging $1,568 in lost time and wasted fuel for each motorist stuck in heavy traffic, according to a new study released Tuesday.

"Driven Apart" addresses the 2009 UMR, and the methodology has been revised—so take the numbers with a grain of salt—but aspects of the critique remain relevant. For example, if you look at the just-released UMR, Chicago looks terrible in the first table: first in congestion cost per consumer, second in yearly delay per auto commuter behind Washington, DC, second in excess fuel per auto commuter.

But if you go down to "other congestion measures," there are better numbers. Chicago's "total peak period travel time" is 102 minutes, good for 26th in the metropolitan areas studied. Washington DC's total peak period travel time is 120 minutes. Atlanta's is 127 minutes per day. New York-Newark is 116.

Compare Chicago to a less dense city, like Charlotte, which "Driven Apart" looks at. In this year's UMR, Charlotte ranks 42nd in yearly delay per auto consumer, and 36th in excess fuel per auto consumer, which sounds great. But it ranks higher than Chicago in total peak period travel time at 110 minutes. Over the course of a year, that's about 32 hours on the road (at five days a week, 48 weeks a year).

The difference, as "Driven Apart" makes clear, is that Charlotte is a sprawling metro area; congestion is not as bad, but total commute time is worse.

In and of itself, the UMR's point is not useless. If you live in Chicago, your commute is shorter in both time and distance, but you spend a greater percentage of that time in congestion, which is frustrating. That's kind of how our minds work, if I remember my Traffic correctly. If you drive for 50 minutes, and spend 20 of it in congested traffic, it's likely more irritating than driving 55 minutes and spending 10 of it in congestion, because you're moving slowly—or more slowly than you think you should be if it weren't for those other people—for more of it. Perception, since it's almost impossible to separate from quality of life, shouldn't be dismissed out of hand. This year's UMR says that Chicago has a relatively high (11th) Commuter Stress Index, which it defines as "The ratio of travel time in the peak period to the travel time at free-flow conditions for the peak directions of travel in both peak periods." Translated, that's a ratio of time in bad traffic to time in good traffic with no regard for absolute time. As a measure of frustration, I think there's a lot of truth to it.

(Consider: you have probably spent time in your car cursing drivers or road crews for making traffic so bad; I certainly have. You have probably not spent time in your car at crusing speed cursing city planners and developers for making cities so big. It's worth trying, it might help vent some commuter stress.)

And you could argue, I suppose, that Chicago's delay time, in a semi-ideal transportation scenario, should be proportionally less since the actual travel distance is shorter. But as a city becomes more dense, thus reducing commute distance and time, reducing congestion becomes harder.

But it's worth considering where the ongoing critique of the UMR comes from. It defines as "excess" time and gas spent in congestion, not driving farther; you could just as easily say that Charlotte drivers pay a greater sprawl penalty. Jarrett Walker, a public-transit planning consultant, argues that it would be a big improvement if the UMR was even just named differently:

The real problem, of course, is TTI's title, "Urban Mobility Report," for a document that's really mostly about congestion.  Only if you live in a very car-dependent city, or care only about car-dependent citizens, can you reduce mobility to congestion in that way.  A more truthfully titled "Urban Congestion Report" would raise no objection.

The critiques aside—and there are many, though it's hard to keep track of how they align with the evolving Urban Mobility Report chronologically—the UMR is useful. But the critiques, whether about methodology or framing, add depth and nuance to an issue we're still not that good at discussing.

Related: Here's a debate and Q&A with Tim Lomax of Texas A&M, one of the co-authors of the UMR, and Joe Cortwright, author of "Driven Apart," at the Congress for the New Urbanism in June of this year, discussing their work and disagreements.


Photograph: Wikipedia Commons (CC by GNU 1.2)