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Congestion report pushes sprawl through flawed analysis

The Texas Transportation Institute today released the final version of their report on congestion, which ranks the DC area tied for first with Chicago in hours wasted in traffic. Unfortunately, the report's methodology completely misleads as to the seriousness of traffic, and TTI is pushing the wrong policy solutions.

Photo by danorth1 on Flickr.

The TTI report narrowly looks at only one factor: how fast traffic moves. 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.

Sadly, despite CEOs for Cities pointing out these methodological problems last year, TTI went ahead and finalized its report without fixing them (PDFs). TTI ranks Portland as worse than Nashville, with a Travel Time Index (TTI) of 1.23 1.15 for Nashville and 1.15 1.23 for Portland. However, because of greater sprawl, Nashville commuters spend an average of 268 hours per year commuting, while the average Portland commuter spends 193 hours per year.

What does this mean for public policy and the Washington region? TTI's data is often used to justify spending money on new freeway capacity, since congestion sounds bad. TTI even promotes this approach. Tim Lomax, a co-author of the report, told the Post's Ashley Halsey III, "You can do little things like stagger work hours, fix traffic-light timing and clear wrecks faster, but in the end, there's a need for more capacity."

"That we are congested is not news, but TTI's report does tremendous damage, because they fail to recognize the primary cause of our congestion and imply that we could simply widen roads to build our way out of the problem," said Stewart Schwartz, Executive Director of the Coalition for Smarter Growth.

What Lomax didn't say, and which Halsey didn't print even though he should know better, is that there are other approaches besides those "little things." What you can do is concentrate future growth around existing hubs with more residents, jobs, and multimodal transportation.

That's what the Metropolitan Washington Council of Governments (COG) is trying to push with its Region Forward plan and the related "What Would It Take?" scenario (PDF). These involve focusing development in places like Tysons Corner and the Route 1 corridor in Fairfax, around underutilized Metro stations in Prince George's, future ones in Loudoun, and MARC and VRE hubs in Maryland and Virginia.

Arlington achieved substantial job and resident growth in its Rosslyn-Ballston corridor without adding to traffic congestion, as has Montgomery with growth in Silver Spring and Bethesda and DC development in places like NoMA and the Capitol Riverfront area. Regional leaders should be less concerned with speeding up existing cars, which just leads to sprawl farther out, and invest more in finding ways to grow the region without adding traffic.

In fact, that's just what the DC region has done. Another, better part of TTI's analysis measures the amount of time savings that come from each region's transit; DC is 3rd best. That metric still doesn't account for the value of people living nearer to their jobs, however.

Between better location and transit, to page 50, congestion has not increased since 1999 even on TTI's flawed scale. That means our region has been successfully growing without adding traffic. Instead of "Washington area tied with Chicago for traffic congestion, study finds," this morning's Post headline this morning could have read, "Washington area's traffic hasn't gotten worse in a decade thanks to smart growth."

It's more than a little baffling, though, that Halsey didn't make any reference to the CEOs for Cities report or the COG work. He also wrote, "Researchers said the depth of the data used in this year's study far surpassed the quality of information used in past years, giving the results an unprecedented degree of accuracy."

So, the researchers at this supposedly very highly regarded institute say that their data is super great, but they and the reporters ignored the widely-publicized critiques of their methodology. Maybe it's time for TTI to stop being so highly regarded.

David Alpert is the founder of Greater Greater Washington and its board president. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He now lives with his wife and two children in Dupont Circle. 


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Funny, I made the same point in the breakfast links.

A few pushbacks:

1. I said this AM that we have two Washington: one very road dependent, the other less so. I'd actually say three: WMATA DC, freeway DC, and suburban DC. I know plenty of people who live in Fairfax and use the freeway for one exit, or don't use it at all. Plenty of others works in MD and drive to VA everyday.

Is development the low-cost fruit? Stop charging so much for long distance metro and parking? More commuter rail? I'm not sure.

Development DOES work -- as Arlington shows, or parts of Mont. County -- but not sure if it scalable. Tysons, for instance.

2. Too much focus on commutes. What really kills you, driving, in the suburbs is errand run day. And schools. Commute driving focus on a few key choke points, which are then overbuilt to deal with the traffic. I'd rather look at development and find ways to shave 2-3 miles off. (Wegmans, despite being a car mecca, is a pretty good example of that).

by charlie on Jan 20, 2011 3:26 pm • linkreport

Is the purpose of Halsey's article to report on the report or to critique it? From reading the article, my impression is that it was primarily the former, although his first paragraph reads a lot like a commentary. If he's reporting on the report, I wouldn't expect him to suggest alternatives. In terms of the Washington Post's transportation writers, that sort of content would primarily come from Robert Thomson (Dr. Gridlock).

The paragraph in this blog post about Arlington's growth along Wilson Boulevard makes a good point, though, and you can very easily compare Arlington's planning with Fairfax County's. I assume many folks here have read Zachary Schrag's book on the history of the DC Metro system. His discussion of Fairfax County's dithering about the Metrorail back in the 1960s, and about their fear of allowing development near the stops, is really damning. The Dunn Loring stop is finally seeing some development, but they utterly dropped the ball when it came to the Vienna stop in particular. (I think Franconia-Springfield has some wetlands issues that prevent too much development, so I suppose they get a pass on that one.) Arlington grafted growth onto the transit lines. Fairfax let growth happen and is now trying to graft a transit line (rail through Tysons) onto that growth, which seldom works nearly as well.

by Rich on Jan 20, 2011 3:37 pm • linkreport

Rich: Good reporting not just tells people that a particular report is out but also informs people about various points of view that inform thinking about it. Too often, Halsey's articles just repeat whatever AAA or some other group says.

by David Alpert on Jan 20, 2011 3:45 pm • linkreport

On that note, David, and to be fair, you appeared to focus almost solely on the Post's article on it.

WTOP, for example, reported on the story, but also noted that the region is 3rd in reducing delay thru public transportation. That's one part of the report that you completely left out.

by Froggie on Jan 20, 2011 3:57 pm • linkreport

David is exactly right in the comment here. Regurgitating a press release is not reporting. Doing some reporting! Nuance, multiple points of view, critiques of assumptions, etc. Not just taking a point of view like Dr. Gridlock might, but pushing your way into the data and assumptions coming from an org to see if there's truth to it or at least a few other points of view worth mentioning.

by Steve D on Jan 20, 2011 4:05 pm • linkreport

#1: Froggie makes an important point that the UMR is one of the only sources that quantifies the benefit of public transportation.

#2. The problem with the CEOs for Cities report is that they basically only used their analysis to bash the TTI and didn't use it to try to promote anything positive. "Sprawl is the problem and the TTI doesn't measure that" - well we know that! Their only answer to the sprawl problem seemed to be an implied suggestion that people should live differently, without any sort of discussion on HOW you make people do that.

It's said time and again here that the reason people live in sprawlville is because we enable them to live in sprawlville through massive road building. So if you want to create a report that says sprawl is the problem, then come up with some solutions like more transit service, more development in urban settings, etc. Just saying "sprawl is bad and makes peoples' commutes longer" isn't going to get anybody to move.

by MLD on Jan 20, 2011 4:54 pm • linkreport

Dave Stroup put it pretty well on Twitter today: "more and bigger roads to solve traffic problems is like buying bigger pants to solve an obesity problem."

by Tim on Jan 20, 2011 5:18 pm • linkreport

I've added something about the transit scores as well. Thanks to those who pointed it out.

by David Alpert on Jan 20, 2011 5:41 pm • linkreport

David, you said, "Between better location and transit, to page 50, congestion has not increased since 1999 even on TTI's flawed scale. That means our region has been successfully growing without adding traffic." However the Washington Metro area wasn't 2nd worst in 1999. How have other cities lowered their measures to be "less worse" in the report. Was it all new capacity road building? Better traffic incident response? More coordinated signal timing? More robust bus or rail transit? Has the DC Metro area's vehicle miles travelled stayed the same or increase while other cities have fallen? Changes in mode and length of those person-trips would be interesting to understand. These are questions that merit some investigation in the report and other sources.

Our transportation system is a balance between the modes used by different groups: pedestrians, bicyclists, rail and bus riders, drivers and passengers. Each mode has a role, some more, some less depending on a community's consensus. To suggest the report has one answer doesn't answer the question. Maybe you should contact Mr. Lomax for his perspective to DC's issues, that would lead to some insightful dialogue instead of an anti-highway screed.

by Some Ideas on Jan 20, 2011 7:33 pm • linkreport

However the Washington Metro area wasn't 2nd worst in 1999.

Actually, at least as far back as 1999, I've been reading in the Post that the Washington Metro area was 2nd worst. However, LA was always cited at 1st worst in the past. Did Chicago and LA somehow switch rankings? Or is this a different study than the one the Post quotes annually. I guess it points to the fact that you can find a statistic to back up whatever point you're trying to make.

by Lance on Jan 20, 2011 10:37 pm • linkreport

David Alpert wrote, seemingly with a straight face:

"Good reporting not just tells people that a particular report is out but also informs people about various points of view that inform thinking about it."

The writers on this site, David included, also often fail to do this. Opposing viewpoints are rarely, if ever, presented, and then only in mocking terms.

Pot, meet kettle.

by Anon on Jan 20, 2011 10:39 pm • linkreport

Last time I checked, bloggers were not necessarily presenting themselves as trained journalists, unlike, say, reporters at the Washington Post.

by William on Jan 20, 2011 11:09 pm • linkreport

Since Texas A&M is a university one can find all kinds of interesting data. You can learn something from data and analysis even if there are flaws (as long as you understand the flaws) Look at the changes between cities in travel time index over time here in this data:

compared to Table 1, pg 22 of this years report here:

Example to consider related to my earlier question -- Seattle has moved a 0.10 lower in the index -- what changed in the data to drive that number? Then in turn what lessons can we glean for the Washington Metro area?

by Some Ideas on Jan 21, 2011 3:35 am • linkreport

Well, William - fascinating point. And I agree with you to a point. But I think there comes a time when a blog becomes big enough and with enough currency to begin to take on journalistic responsibilities. Even if it doesn't want them. I'd say GGW is clearly there. If the site is able to attract leading political and government figures to come and do interviews here, if the damn thing becomes part of the political conversation about how to select council members (again, willingly or not), then that means the local society has begun to give it a great deal of respect and weight.
GWW continues to earn that respect by seeking out and reporting on information that is relevant and of interest to a wide enough section of folks and by starting important conversations about policy issues that make a difference in the lives of just about everyone. But there are definitely more than a few clunker posts here by folks with a point to make and who seem unaware of any broader responsibility to fairness, truth, rhetoric, etc. I'd lay the blame for that firmly in David Alpert's lap - it's his site and so his responsibility to establish the standards for those who are allowed to write here.
Because of the subject matter and breadth of coverage, it's still one of the first blogs I check on a daily basis but I definitely find myself wincing from time to time at the immaturity and simplicity of some of the writing.

by Josh S on Jan 21, 2011 8:50 am • linkreport

Blogs are like opinion columns, they have an upfront bias and direct point of view. They exist to provide commentary from a specific point of view.

Journalistic news articles are supposed to provide readers with different valid points of view.

And you can thank Fox News for blurring the line between opinion and news so much that now we have to explain to people what the difference is.

by MLD on Jan 21, 2011 9:08 am • linkreport

Proper commercial/office space zoning could most of the transportation problems in the region. It's going to raise the cost of office space, but I'd argue that it's cheaper than building more public transportation and/or more highways.

by Frog on Jan 21, 2011 10:21 am • linkreport

"Clearing the wrecks faster" will make a meaningful difference? Sure, if one confuses the street where I live to be the functional equivalent of Talladega Superspeedway.

by KadeKo on Jan 21, 2011 1:04 pm • linkreport

Traffic in DC is not as bad as the report indicates -- it's worse. It is compounded by rude and inattentive drivers.

by Johne37179 on Jan 21, 2011 1:43 pm • linkreport

My experience with the Washington Post has long been that traditionally they have often tried--often, but not always, especially in the political context--to separate news articles from analysis articles, and one way to tell which is which is that analysis (which may include columns) has normally been given italicized headlines while news has been given regular headlines. A news article about a report of this sort would normally tell the reader that the report existed and what it said; an analysis article would separately assess the report's validity. There's a legitimate rationale behind separating the two types of reporting in that manner, although it's also fair to say that if you're going to report that way, you need to do it consistently. I think the Post has a tendency to be inconsistent with respect to these things, again especially when it comes to political reporting.

I don't want to sound like I'm flat-out defending Ashley Halsey. I remember when he used to contribute to Dr. Gridlock's blog and a lot of complaints were made because his postings tended to be sloppy and hard to read (the thing I most recall is that he never put a blank line between paragraphs). To the extent the editors want a certain thing, though, it's not necessarily his "fault" that he didn't critique the report. There's a fair chance that critiquing it wasn't part of his assignment, and there's also a very good chance that if he were to go beyond his assignment (I do not know whether he would, mind you), the editors might cut it. Newspapers tend to lay out their pages prior to the stories being handed in, and the reporters either have to write their stories to fit the space or see the stories cut down.

by Rich on Jan 21, 2011 3:09 pm • linkreport

"Last time I checked, bloggers were not necessarily presenting themselves as trained journalists, unlike, say, reporters at the Washington Post. "

That is hardly necessarily true regarding the Washington Post:

And such error comes along with more error correlated to a bias:

by Douglas Willinger on Sep 22, 2011 6:15 pm • linkreport

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