Last week the Texas Transportation Institute released the 2011 edition of its benchmark Urban Mobility Report. It is packed full of useful statistics about roadway networks, congestion, and public transit, though is not without its critics (see below). I’d like to highlight some of the more interesting findings out of this.
The Value of Transit
One of the values TTI estimates is the number of additional hours of delay each peak hour commuter would incur annual if public transportation were discontinued. In effect, this is one key benefit to motorists of public transport. Here are the top 10 cities:
To further show the value of transit to New Yorkers, let’s do a quick back of the envelope type calculation for illustrative purposes. The median household income in metro New York is $61,927. If each home with an auto commuter in it has one and only one commuter who obtains the average benefit, and incomes of auto commuters follow the overall, then this auto benefit is equivalent to 1.66% of income. You can think of it as sort of like a 1.5 percentage point cut in the income tax rate for those households, just based on the value delivered to them.
Now of course those households probably make contributions towards transit through taxes and otherwise, but clearly they are also getting a return even if they don’t ever ride transit personally. Also, this considers only peak period commuters, not non-peak drivers (who also experience significant delay in New York) or the value of transit to commercial vehicles, which is likely big as well given than NYC incurs over $2 billion in cost due to trucking delays from congestion.
After NYC, the savings drop off rapidly, but there are six additional cities with more than 10 hours of delay savings per peak commuter, so they probably get something material out of it.
On an aggregate basis, the total value of congestion avoided as a result of public transit is impressively high as well, as this look at the top ten cities shows (in millions of dollars):
Commercial Vehicle Traffic
TTI has also started trying to break out the cost of delays to commercial vehicles. Here are the top ten cities for trucking congestion delays, in millions of dollars:
When looking at congestion, I think it’s also relevant to consider the size of the roadway network relative to the population. TTI reports freeway and arterial lane miles, so we can do this calculation. Here are the top ten cities for freeway lane miles per capita, for metro areas greater than one million people.*
Here are the bottom ten:
Note: Riverside has a likely data error in the master TTI spreadsheet the artificially lowers its score here.
TTI and Its Critics
I could do a lot more on the TTI report, and maybe I will in future posts, but I wanted to address the notion that TTI’s measures have been “debunked” as some have said.
The root of this goes back to a CEOs for Cities report called “Driven Apart” that basically says that TTI and the way they measure things are wrong, and that different measures would be more appropriate.
I doubt most of those who link to that report approvingly have ever read what it says in detail. I’ll freely admit I haven’t either. But having looked at previous work Joe Cortright did, I’m confident it’s technically sound.
Regardless, I think that this is never going to gain mind share with the greater public, and that only the hard core urbanist true believes are going to be impressed with it.
Let me explain why in contrast to the extremely successful CEOs for Cities “Talent Dividend” research which shows the size of the prize for increasing educational attainment. Firstly, in education there is already unanimous consensus that we need to raise education attainment, even if there are debates about getting there. So this is preaching to the crowd. Second, the idea that raising educational attainment boosts incomes its intuitively obvious because in our everyday experience, the people we interact with on a daily basis who have more education tend to make more money. And the causal link is clear. The Talent Dividend merely takes this everyday experience and makes it real at the macro level, showing the size of the prize. Also, its policy prescription of shooting for a one percentage point increase in college degree attainment is intuitively achievable.
Now contrast this with Driven Apart. Here we have low consensus about what we want to achieve. Additionally, the notion that places like Chicago are somehow better than Charlotte for drivers is counter-intuitive and flies in the face of the everyday experience of Chicagoans.
I am inclined to be pro-urban and pro-transit. But I’ve commuted in Chicago and can tell you that traffic is simply horrific. Complaining about traffic and the CTA are two of the most common Chicago pastimes. Not only that, traffic has been getting worse over the years. This is not just commuting. Expressways like the Kennedy and Eisenhower are now basically backed up all day. Even on a Saturday or Sunday, traffic frequently grinds to a halt. As near as I can tell, the ramp from the inbound Ryan to the outbound Ike is backed up effectively 24 hours a day. The numerous six way intersections like Belmont/Lincoln/Ashland and Fullerton/Damen/Elston make driving around the city a chore as you sit through multiple lights. (And hope you don’t have to turn left).
Now the Driven Apart report doesn’t deny this, but simply suggests that’s the wrong way to look at it. Rather, we need to consider distance, etc. and that it’s the total time driving that counts. Here’s the chart comparing Chicago and Charlotte:
Driven Apart suggest that the real culprit we should be looking at is sprawl. I agree that’s a key problem. However, Chicago is one of the most sprawling regions in the US. Indeed, that’s one reason it’s traffic is so bad. This has been tirelessly documented by the Center for Neighborhood Technology and others. Talk to any urbanist planning group in Chicago, and restraining sprawl is a top priority. As I noted in my census coverage, virtually all Chicago growth in this stagnant region has been in the exurban areas. The region seems to actively promote this, with items such as extended Metra service to Elburn and a planned $69 million interchange expansion at I-90 and Route 47 in exurban Huntley. The sprawl has even spread into Rockford, whose metro area is seeing a big influx of people from Chicago despite its depressed economic state.
Beyond sprawl, Chicago also has the third lowest freeway lane miles per capita of any metro area in the US greater than one million people, though it does better when looking at arterial lane-miles.
So whatever the merits of Driven Apart (and I’m not claiming any of it is per se wrong), implying something like Chicago is better than Charlotte for drivers falls into the category of “extraordinary claims require extraordinary proof.” Something that is effectively a technical argument is never going to sell, particularly when it flies in the face of the everyday experience of people who live in these cities. I know both Chicago and Indy (another city cited for its sprawly commutes in the Driven Apart study) intimately from a driver’s perspective, and there’s simply no comparison. In terms of getting places, Indy is just indisputably better to me. I don’t think I could ever be convinced to think otherwise.
Given this, I think the idea that traditional measure of congestion are going to be dethroned is a long shot at best.
* Note that TTI urban areas are not metro areas but a bespoke region. The population used for thresholding which regions to include was the Census population of the metro area, but the population value used for per capita calculation was the population of the TTI region as reported by TTI.