Auto Congestion: D.C. Area Ranks Second in Nation

Traffic is bumper-to-bumper as motorists are diverted. Greater congestion is expected Monday, when many commuters return from July 4 vacations.
Traffic is bumper-to-bumper as motorists are diverted. Greater congestion is expected Monday, when many commuters return from July 4 vacations. (Gerald Martineau - The Washington Post)
Tim Lomax
Research Engineer, Texas Transportation Institute and Co-Author of Traffic Study
Wednesday, July 8, 2009; 2:00 PM

Although traffic has lightened up a tad in almost every other major metropolitan area in the nation, the misery index in the Washington area has increased, according to the annual national traffic study (2009 Urban Mobility Report) released today by the Texas Transportation Institute.

Washington continues to rank second to Los Angeles in auto congestion, which causes the average driver on the area's highways and byways to waste about 62 hours a year crawling through traffic, according to the study, which used data from 2007.

Tim Lomax, research engineer for the Texas Transportation Institute and co-author of the study, was online Wednesday, July 8, at 2 p.m. ET to discuss the findings and address questons about whether the region and the nation's current political and economic focus will work in solving traffic congestion problems.


Tim Lomax: Howdy, Tim Lomax here to talk about congestion in the Washington DC region and the country as a whole.

I'd like to hear what you'd like to know. I will answer your questions - or tell you I dont know.

How's that?



Blame Arlington for I-66: Is I-66 the only major road in any U.S. region that gets narrower as it approaches the city?

With Arlington's every attempt to stop expansion of I-66, they have only themselves to blame for the side streets of Arlington being clogged.

Tim Lomax: I don't know of many freeways in that situation, but many regions have freeways that get narrower in places - we call those "bottlenecks" - they are often the cause of traffic congestion. They aren't always easy to fix either.


Frederick, Md.: Mr. Lomax,

Those of us up in D.C. outer suburbs (i.e. Frederick), have been following the multimodal study of the I-270/U.S. 15 corridor quite closely. It seems like a number of options would be helpful in easing the 30-mph average on 270 from Frederick to the Beltway. What have you heard about any movement to improve traffic conditions in this corridor, and could you hazard a guess about a timeframe for these improvements to be completed?

Tim Lomax: I haven't heard about this corridor specifically.

But corridors like this benefit from a multi-stage solution. That is, fix the small problems and those that can be addressed immediately. And then work on the larger problems. In the near term, programs like removing crashes rapidly, retiming traffic signals and freeway ramp signals, telecommuting, using public transportation and carpooling, flexible work hours are strategies that work. They dont solve the whole problem, but they can make it easier to live with while the long term solutions are discussed and built.


Kingstowne, Va.: Would you address some of the methodology used for this report? What is "delay," the additional time from "normal" rush hour traffic for the region, or the additional time from driving slower than the speed limit?

What roads are part of the calculations? Interstates, state highways, any road a commuter travels on to get to work?


Tim Lomax: sure - you can find the methodology at - then look for "How we got the numbers"

Delay is the extra time compared to (basically) the speed limit. We cover major streets and freeways in the peak periods - 6 to 10 am and 3 to 7 pm.

_______________________ Urban Mobility Information


South Riding, Va.: Is there a real solution to our traffic problems? And without having to tear down homes and buildings or force people from the outer suburbs to move closer to D.C.

The way I see things, we don't have a lot of alternate routes. If something happens on US-50 in Loudoun County, there aren't any other roads to bail out on. There are no trains to take. You just have to sit in traffic and wait. I would love to be able to cross into Maryland from Rt-28 or the Fairfax County Parkway instead of having to get to the American Legion Bridge.

The suggestion for people to just move to a home close to their job isn't practical. Unlike 20 years ago when people stayed with the same job, people change jobs every few years and moving each time isn't practical.

Tim Lomax: The problem you describe is present in most major urban areas - no easy construction options and US residents change jobs frequently. That's why we think a broad set of options are important. Some are the responsibility of the agencies - rail, bus, road, traffic signals, those sorts of solutions. But some are also the product of individual decisions. We've seen a lot of benefit to employers who allow their employees to have flexible work hours, or to telecommute (even if its only for a few hours in the morning).

Obviously there are a lot of people who have many different factors that they consider in their job and home locations - traffic congestion is often the price they're willing to pay to be close to a spouse's job, nice schools for kids, elderly parents, nice entertainment.

That isn't to say we should ignore the problem - it does suggest that we all need to take some time to think about travel options.


Silver Spring, Md.: Did the study look into the differences in traffic congestion b/w VA and MD? I would think getting into D.C. from Maryland would be less congested because there are more routes to take.

Tim Lomax: We were not able to look at that level of detail. If we did, i think we'd see traffic congestion worse around the big job centers in all three parts of the region.


New Orleans, La.: Given that:

- We need to reduce carbon emissions - We need to reduce oil use - Roads have a negative cost elasticity of supply (the more we use them, the more expensive they are; the marginal cost of new road capacity is higher than the average cost) - We simply cannot build enough roads to eliminate congestion, even with an unlimited budget, since vehicle miles traveled will just grow to fill all available space - Roads cost 40,000+ deaths/year and hundreds of thousands of life altering injuries, as well as encouraging obesity/diabetes.

Shouldn't road congestion simply be accepted and ALL efforts should be made towards expanding Metro, Marc, VRE and eight viable light rail projects in the D.C. area?

Split the Red Line at Bethesda, with a new branch serving Georgetown to Union Station, push the Green Line towards Baltimore, etc.

Also take street lanes from cars and expand bicycling, parking from cars to park bikes (8 bikes for 1 car), etc. A given area can serve many more people as two bike lanes than one car lane.

There should be minimal delays and maximum connections for those that do not drive and let those chose to drive live with their congestion.

Tim Lomax: I certainly hope that the roads that are built fill up - if not the money was spent on a project that wasn't needed. I hope the same thing for transit projects, and sidewalks and bike lanes.

I don't think we can just add public transportation - many of the developments aren't set up for that mode and it costs a lot of money to serve less dense areas. Just like you have a diversified investment portfolio, you also need a diverse set of solutions. The risk you run is that some percentage of your job base will move away if it becomes too difficult to travel. Think about the number of jobs that can be done from anywhere (my job as chat room guest, for example) - those are more likely to move to places that people want to be.


Frederick, Md. Again: Thanks for the response, Mr. Lomax. I find that there must be some significant disconnect however, when one of the area's most congested stretches fails to have made it onto your radar in the course of the study. I have only to believe that the local politicians are failing to make the needs of their constituents known to those who have power to improve the situation.

Tim Lomax: Our database contains that road, we just didn't analyze each road in the 439 urban areas in the US. We have analysis tools that group the roads to give us a regional trend. More detailed study is needed for each corridor.


Arlington, Va.: The comparison of D.C. to other areas and the increase in traffic here - is this a sign the job market is better here? Does your study really reflect people moving here for work?

Tim Lomax: We saw population and traffic congestion go up in the DC region, and the number of roads and transit service didn't go down. I think the job market was fairly healthy (remember our study data ends in 2007). So I see the economy as a factor in the congestion growth. We've seen that in many other places.


Washington, D.C.: Do you know of any studies that have attempted to measure how well people drive, and how that might affect traffic problems? I'm willing to bet that the drivers in the greater D.C. area rank last by any conceivable measure of skill.

Tim Lomax: "Driver skill" isn't something we measure. I suspect we could get a nice grant from sports car manufacturers to study that.

I don't think that enforcement of traffic laws is a part of the solution. A large part of congestion is related to collisions, and those are related to individual choices - whether its drunk driving, speeding, reckless or inattentive drivers - those all have a negative effect on traffic.


Washington, D.C.: How does transit use factor into your analysis? I find it notable that Metro usage over the past year increased, yet delays by drivers increased as well. Does this mean that our infrastructure is truly at saturation?

Tim Lomax: You are right - transit ridership grew from 05 to 07 and so did congestion. I think that says that we aren't deploying the solutions fast enough or extensively enough. Some of that is a funding issue and some of it is a public support issue.

Its difficult to put together coalitions to approve and fund transportation expansions. Its particularly difficult in situations where there is more discussion about the small percentage of projects that are the "lightning rods" than there is action on the number of projects that the community generally agrees upon.


Fairfax, Va.: How did you come up with the 62-hour waste of time "crawling" through traffic that was mentioned in your quote in The Post?

Tim Lomax: We have this dartboard....

Actually we use a database prepared by the states and submitted to the Federal Highway Administration. We have a set of procedures that take the traffic volumes, the number of lanes and the congestion reducing programs (like removing stalled vehicles rapidly or re-timing traffic signals) and estimate the travel speed on each link of the road network.

We also look at what would happen if we dumped all the transit riders back onto the road network to get a sense of how much public transportation contributes to the solutions (we dont think that is a real option, and the actual consequences would be much worse than just extra travel time).

See our methodology at - then "How we got the numbers"

_______________________ Urban Mobility Information


Washington, D.C.: I have lived in this area, first Cleveland Park and now in Ballston, for eight years and one phrase describes this area when it comes to traffic...NIMBY.

We can't build more roads because it increased car use and pollution, we can build more metro lines because we are cutting down trails, etc. Basically, there is no sense of the greater good in this area. Each little section is able to derail major transportation projects for usually ridiculous reasons.

Look at Metro...why are we expanding to Dulles before we fix what we have? The tunnel through Rosslyn is backed up every day as it is now...and the Orange Line is overflowing. So we are going to stick more passengers and more trains through the tunnel? Of course not, the project should have been conditioned on having another tunnel dug into D.C. (The dirty secret is the Blue Line is going over the Yellow Line bridge no matter what once this boondoggle is done). Who is going to take an hour long Metro ride from D.C. to Dulles anyway? Then on the extension route...we aren't putting the section through Tysons underground, which would create an area like the Rosslyn-Ballston stretch which everyone agreed is a model.


Tim Lomax: "NIMBY" is something we see a lot, but I think its a fact taht in a democracy we need to be creative about how we craft solutions. Not every situation has a solution, but many problems have been solved by serious discussion that start with recognizing that even the NIMBYs may have a valid reason for their position. Its rarely a yes/no or good/bad kind of decision.


Washington, D.C.: The Post article mentioned that "experts agree that no single approach -- building more roads or commuter rail lines -- will reverse the trend. They say it will require political courage to do the unpopular and a public willingness to sacrifice a little and, perhaps, pay more." Can you explain what this means?

Tim Lomax: "Courage" isn't a word I use, but elected leaders need to have support for their positions, otherwise they may not be representing their constituent's views. In many cases, "courage" looks like one group wanting their point of view to be favored even though the majority doesn't think that way. "Communication" is the key - marketing your program to get approval.

We think the range of solutions that ought to be considered include agency actions, business responses and changes in traveler patterns. The last two might look like "sacrifice" but I think many cases it is just "change" to a different and better way of getting to where you want to be.


Wiredog: We're number 2! Woo hoo! Someone tell (Gene) Weingarten!

What do we have to do to be number 1?

Tim Lomax: Los Angeles is at 70 hours of extra travel time per peak period traveler & DC is at 62.

Perhaps if y'all were to close the Beltway between Tyson's Corner and Springfield, you would shoot up to #1.

In the Coaches poll, that is.


D.C.: No question, just a comment -- how on earth do you consider Frederick to be a suburb of D.C.?

Tim Lomax: I don't believe the DC urban area that we use includes Frederick. I did drive out to see a minor league baseball game (the Keys, I think) there once. Maybe that makes it a distant suburb.


Re: Taking Blame For I-66: I-66 having 4 lanes in Arlington was a legal settlement. It wasn't going to be built, for residents followed the legal process and had it stopped. The compromise settlement was to tear up neighborhood, but limit the number of lanes and rush hour access. It could have been built where Rt. 50 exists, but politicians in Fairfax didn't want it there.

Tim Lomax: Its also important to note that the number of people on I-66 is relatively high in the peak direction due to the carpool restriction. So if you think about lanes of people, I-66 may be among the most productive in the region.


Housing Choices?: You talk of people's decision to live far from the city as if they have a choice. Most people cannot afford to raise a family in Arlington or other city-adjacent places (except for some pretty bad neighborhoods). Heck, Vienna used to be the outer suburbs and now it's becoming a premium place to live. Now, South Arlington and other not-so-nice places, I don't know what the story is there. I'm surprised there are so many run-down areas of Annandale and Falls Church. I'm baffled, how did it all end up this way?

Tim Lomax: American cities are still changing - that's not a great answer but its true. The neighborhood redevelopments also have negative effects. As you note, people make choices for many reasons - some related to cost, others to school location and quality or other factors.

I think transportation has an important role in the economy and society - its up to leaders and residents to decide how to balance those many competing priorities. The Urban Mobility Report tries to provide information so that people can make informed decisions.


Silver Spring, Md.: Will someone grab the representative from Wyoming who refused to fund the Metro? I would like to see him sit for a hour in traffic every day. His stupidity of not funding the Metro contributes to this mess.

Tim Lomax: Sorry but I don't know about this issue.


Bowie, Md.: How does Philadelphia always do so much better than the other large northeastern cities? (Depopulating after the era of road building peaked?)

Tim Lomax: Yes, partly, I think that's true. I think slow growth in population that has allowed the transportation expansions to have an effect is a key element. They also have a very diverse set of road and public transportation options.


Tim Lomax: Thanks very much for your questions.

If you have any more, try our website:

Texas Transportation Institute

Good luck commuting and travel safely.


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