Texas DOT’s Own Numbers Cast Doubt on Its Story of Ever-Rising Traffic

DailyVMTPerCap_DalHarTar_2006-2015
On average, each person who lives in Texas’s three most populous counties drove fewer miles on Texas DOT roads in 2015 than in 2006, according to TXDOT’s DISCOS data.

Back in 2015, the people of Texas were asked by the legislature and Governor Greg Abbott to meet the challenge of the state’s projected traffic growth by enacting a constitutional amendment to require road spending for the next decade. The people agreed and voted to allocate about $38 billion in state taxes for the Texas Department of Transportation (TXDOT) — guided by the Texas Transportation Commission (TTC) — to build and maintain roads.

But what if the story about Texas growth that’s been drilled into the collective awareness by road builders is not quite accurate? What if there’s a major shift in urban areas toward driving a lot less?

The story that we’ve been told is that Texas is growing at a tremendous rate, with our urban and suburban counties essentially spiraling out of control with no end to traffic in sight. That’s the justification for throwing many billions of dollars at paving new roads. Looking at TXDOT’s District and County Statistics data (DISCOS), you can see the amazing amount of driving Texans do every day — county by county and metro area by metro area.

We drive a lot.

But the key question is not how much we drive — it’s whether the amount we drive is increasing. I was curious how driving levels have changed over time, so I asked TXDOT for historical DISCOS data, which aren’t readily available online. I was curious whether a look back at ten years of DISCOS data might change the story.

It turns out that TXDOT’s data show a reduction in traffic from 2006 to 2015 in Harris, Dallas, and Tarrant Counties — the three most populated counties in Texas. If this is an accurate characterization of travel patterns, the story that Texas tells itself about traffic needs to be revised.

While Harris County added about 682,228 people between 2006 and 2015, total traffic in 2015 was 2,991,492 fewer miles than in 2006, according to TXDOT data. Dallas County added 199,985 people, but saw 3,326,231 fewer daily traffic miles, and Tarrant County added 319,598 people and saw 667,317 fewer miles.

Adjusting for population, that means the average person in the three most populous counties in Texas — home to a full third of the state’s population of Texas — drives about three miles a day LESS than ten years ago. (The per capita decline in Harris, Dallas, and Tarrant counties was 2.93, 2.61, and 3.33 miles per day, according to TXDOT data.)

This is a very different story than the one told to the people of Texas when they were asked to require billions in annual road spending less than a year ago.

There are some key caveats to understand when looking at this data. The TXDOT DISCOS traffic data only includes estimates of the amount people are driving on TXDOT “on system” roads and highways. In general, we do not know from the TXDOT DISCOS data how much more or less Texans are driving on city and county roads, or on toll roads not under TXDOT’s control.

In fact, major players in Texas transportation policy don’t put much stock in the DISCOS data as a reflection of what’s happening in the region. They don’t seem to believe it is possible that travel behavior in the most populous counties in Texas may have changed after decades of adding more compact development.

We’ll look at why that might be, and what the implications are, in part two. Stay tuned.


This post is made possible by a grant from Sutliff & Stout, an accident and injury law firm in Houston Texas. The content is Streetsblog’s own, and Sutliff & Stout neither endorses nor exercises any editorial control.

  • Jay, do you have any information on whether TxDOT transferred control of some older state highways that act more like surface stroads to the cities of Houston, Dallas, and Fort Worth? There has been some discussion in Austin about the city taking over streets like Lamar (SH 343) and Airport (SH Loop 111). I’m wondering if these kinds of transfers might reduce the VMT on the TxDOT system.

    • Jay Blazek Crossley

      I don’t know. It is possible that situation would alter these numbers. However, I did look at lane miles and those three counties did all add total TXDOT lane miles during that time.

    • Jay Blazek Crossley

      I don’t know the answer to your question. However, I did look at whether the large counties had more or less total lane miles in 2015 than 2006 and the answer was yes for all of them. So the explanation probably is not that TXDOT transferred ownership of enough roads in Harris, Dallas, and Tarrant to make these numbers fishy. However, the next post will explore the possibility that the Grand Parkway and similar private or locally owned toll roads have actually shifted enough traffic off TXDOT roads to account for the numbers we see here.

      At the end of the next post, which is as far as I have gotten on understanding VMT in Texas, we basically don’t know the true picture of VMT in Texas. To know the true picture, we would need to know county level data on VMT on locally owned and privately owned toll roads and we would have to figure out a way to estimate VMT on local streets. It is possible that nobody has any idea of how to do that. I don’t know. One theory is you could just compare traffic counts over the years on certain spots and try to get some kind of way to estimate if people are driving more or less on local streets.

  • jcwconsult

    Extrapolating statewide numbers from three counties is not research.

    James C. Walker, National Motorists Association

    • Alicia

      Those “three counties” are the three most populous counties in the state. They contain three of the five largest cities in Texas. They aren’t randomly selected.

    • Kenny Easwaran

      Are the numbers relevantly different statewide? It’s unfortunate that this post doesn’t mention them, but it’s also unfortunate for me that you don’t, so I just have to guess. (Or put in the work to aggregate the county-level data from the linked spreadsheet.)

      • jcwconsult

        Real research checks the whole state. Samples, even the top three counties, could have been done to skew the results. I do NOT know that to be the case, but samples rather than the full data are often not research. Total VMT is up sharply nationwide, so these results from just three counties make me ask more questions.

        James C. Walker, National Motorists Association

        • Alicia

          Just looked at another sample (the first five counties, alphabetically). One of those counties (Andrews) has basically doubled VMT (from about 471 to about 926 million miles). I suspect if I look into it I would find a huge population and construction boom there. Another, Anderson County, has seen a small increase, from 1273 to 1134 million miles. The other three, Angelina, Aransas, and Archer county, have declined. I don’t have the time to analyze all the data points, but it does seem like there is a general decline, based on the ones I looked at.

          • jcwconsult

            All I know is there has been a serious upward spike in total VMT nationwide – and it would take real totals to show that Texas was an outlier with lower total VMT.

            Maybe the issue being clouded here is “annual mileage per capita” versus “total miles driven”. The needs of the road network are no different whether three people drive 10,000 miles per year each, two people drive 15,000 miles each, or one person drives 30,000 miles.

            James C. Walker, National Motorists Association

          • Alicia

            The needs of the road network are no different whether three people drive 10,000 miles per year each, two people drive 15,000 miles each, or one person drives 30,000 miles.

            That’s pure nonsense – of course, those three scenarios will make a difference in how the road network is planned: where the people are headed, and whether they always drive separately or sometimes carpool. The number of vehicles also makes a difference in how many lanes are needed.

          • Jay Blazek Crossley

            Hello James, Thanks for your comments. They are fascinating. This is just a simple blog post about some quite remarkable finding.

            1/3 of the people in Texas live in those three counties, by the way and those three counties have probably been adding more people than much of the rest of the state combined.

            I have been looking at statewide numbers and shared the spreadsheets so you could look as well. According to the TXDOT DISCOS data, the entire state of Texas drove an additional 9,250,036 daily vehicle miles traveled comparing 2015 to 2006. This in a state that drove 487,020,024 daily vmt in 2015, meaning this was only a 2% increase in total daily vmt over that time, a remarkable finding.

            VMT per capita for the entire state of Texas fell from 20.5 average daily VMT to 17.7 average daily VMT, an astounding finding.

            If you were trying to more effectively lobby for road spending, you might prefer to point out that I picked 2 particular years and compared them as opposed to looking at moving averages or other measures that would smooth out over time. However, I have already considered that response and looked at the patterns over time, and they are very consistent – across the state as a whole, with the average Texan driving less year after year.

            You also might argue that the TXDOT DISCOS data does not represent all the actual driving in our state and might be a terribly flawed way to measure VMT. This is in fact the subject of the follow up post. So I hope you get to check that out.

          • Jay Blazek Crossley

            I really like your use of the word “needs”, especially when you are explaining that you propose a socialist belief system where we should allocate transportation spending based upon each person’s “needs” and not instead a more free market approach that properly assigns costs to personal decisions, where each person can choose to pay more if they choose to drive twice as much as someone else.

          • Jay Blazek Crossley

            By the way, I was checking out the National Motorists Association’s 990 on guidestar (http://www.guidestar.org/FinDocuments/2014/391/951/2014-391951971-0c3109bd-Z.pdf) and your public support test seems like it might be incorrectly done. For this to be true, you are claiming that no single person gave more than $740 to NMA in 2010 or $1,126 to NMA in 2014, with similar numbers for the in between years. Perhaps you really do raise $50,000 all from donors of smaller amounts, but it seems very unlikely for a nonprofit organization to have no single donor over $1,126 during any year over a period of five years.

            Also, in Part V, Line 35a of your 2014 990, you state that your organization did not receive more than $1,000 in unrelated business income, but your website clearly states that you sell advertising. Did you really sell less than $1,000 in advertising in 2014? That seems unfortunate that didn’t work out as a funding stream for you.

          • Jay Blazek Crossley

            The US Department of Transportaion does not seem to agree with your serious spike proposal. Here is a quote: “Since 2004, total VMT in the U.S. has declined slowly. In 2012, total VMT reached the lowest level since 1996” from this page: https://www.transportation.gov/mission/health/vmt-capita

          • jcwconsult

            2015 saw about 3.15 trillion miles traveled, a record, and 2016 is on track to be a bit larger. VMT declined in recession years which is normal and has rebounded to even higher levels.

            James C. Walker, National Motorists Association

    • Jay Blazek Crossley

      Hello James, Thanks for your comments. They are fascinating. This is just a simple blog post about some findings that I found pretty remarkable.

      1/3 of the people in Texas live in those three counties, by the way, and 40% of the population growth in the last ten years of the entire state of Texas has occurred in those three counties. The vehicle miles traveled occurring in just those three counties today accounts for 25% of the total driving that occurs in the entire state of Texas, according to this TXDOT DISCOS data.

      I have been looking at statewide numbers and shared the spreadsheets so you could look as well. According to the TXDOT DISCOS data, the entire state of Texas drove an additional 9,250,036 daily vehicle miles traveled comparing 2015 to 2006. This in a state that drove 487,020,024 daily vmt in 2015, meaning this was only a 2% increase in total daily vmt over that decade, a remarkable finding for a state population that grew by 18% over the same time period.

      VMT per capita for the entire state of Texas fell from 20.5 average daily VMT to 17.7 average daily VMT, an astounding finding.

      If you were trying to more effectively lobby for road spending, you might prefer to point out that I picked 2 particular years and compared them as opposed to looking at moving averages or other measures that would smooth out over time. However, I have already considered that response and looked at the patterns over time, and they are very consistent – across the state as a whole, with the average Texan driving less year after year.

      You also might argue that the TXDOT DISCOS data does not represent all the actual driving in our state and might be a terribly flawed way to measure VMT or allocate transportation spending. This is in fact the subject of the follow up post that will appear next week. So I hope you get to check that out.

      Finally, I really like your use of the word “needs”, especially when you are explaining that you propose a socialist belief system where we should allocate transportation spending based upon each person’s “needs” and not instead a more free market approach that properly assigns costs to personal decisions, where a person can choose to pay more if they choose to drive twice as much as someone else.

      • jcwconsult

        The NMA has long supported proportional and fair user fees for the roads, most cheaply collected via the fuel tax which also rewards using fuel efficient cars to reduce foreign oil imports.

        James C. Walker, National Motorists Association

  • lball

    The bureaucrats will likely credit the (10 block?) light rail system in downtown Houston for having a far-reaching “ripple effect”! In these urban centers, I’d guess that telecommuting and retirement are the causal factors. IF, and that’s a big if, these numbers aren’t predetermined, manufactured crap for an agenda we haven’t been told yet.

  • SocraticGadfly

    Just for everybody’s clarification, here’s the org that Walker represents, per Wiki; based on the link, I suggest taking him with a grain of salt. https://en.wikipedia.org/wiki/National_Motorists_Association

  • david crossley

    Aside from the numbers not recognizing driving in the off system roads and streets, there is also the possibility that Houston’s evolution as a massively polycentric region has enabled people to live closer to their jobs, and also to have access to all sorts of amenities nearer to their homes. The Central Business District, still the largest job center, has only 6 percent of all the jobs in the region. I would have a look at two things: Jay’s earlier job centers map and the H-GAC online Blue Map.

  • Pingback: Is Something Wrong With TXDOT’s Data on Driving? – Streetsblog Texas()

  • Pingback: Today’s Headlines – Streetsblog Texas()

  • This is interesting. Reminds me of Disney. BOOM!

  • Pingback: Today’s Headlines – Streetsblog Texas()

ALSO ON STREETSBLOG

STREETSBLOG USA

Texas DOT Isn’t Learning From Its Horrific Road Fatalities Calendar

|
Graphic: Texas DOT This calendar is published by the Texas Department of Transportation as part of its traffic safety efforts. It shows how many fatal collisions and traffic deaths happened every day of the year. On average, someone is killed every two and a half hours on Texas streets, and someone is injured every two minutes, according to TxDOT [PDF]. Texas hasn’t had a [...]
via Not of it.

Previewing the "Texas Big Six: Make No Small Plans" Event #TXB6

|
The American Planning Association’s Texas Chapter will host “The Texas Big Six: Make No Small Plans” workshop on Friday, March 4th at the Texas State Capitol Building in Austin, Texas. Texas is channeling its inner Daniel Burnham. The Chicago architect responsible for 1909's The Plan of Chicago never uttered the exact words that are the theme of the 2016 Texas Big Six workshop, but the idea sets a guide for the future of the six largest cities in Texas.In 2014 the American Planning Association's Houston Section hosted "The Texas Big Six 2040 - Conversations about Our Future", where the planning directors from Texas' six largest cities (Austin, Dallas, El Paso, Fort Worth, Houston, and San Antonio) addressed the major plans, policies, and projects that will shape the livability, resiliency, and competitiveness of these cities and each region's future.The biennial event is back for 2016, with each planning director discussing the “game changers” in their cities and regions that will improve or enhance the transportation, housing, economic development, environment, public health, and culture of their respective cities.  The event is a unique time for planners, engineers, designers, architects and students to openly discuss the major issues of their cities. The conversation that takes place, and the understanding of how other cities in a region or state respond to challenges, is tremendously valuable.A Thursday, March 3, 2016 evening happy hour with workshop attendees will be hosted at III Forks Steakhouse in Austin. Friday, March 4, 2016 will feature the all-day event from 8:30 AM to 4:00 PM.The event's keynote speaker is Steve Cover, who serves as the Director of the Department of Community Planning, Housing, and Development in Arlington County, Virginia. Mr. Cover previously served as the Director of Planning and Community and Economic Development for the city of Madison, Wisconsin.As we look forward to the event, it's interesting to know what might be some of the major topics discussed by each planning director, or topics that may be brought up by planners or others at the event. Here's a look at some possible topics: (Graphics are from the event's program.)A few weeks ago Alana Semuels published an article at The Atlantic titled "El Paso's Uphill Battle Against Sprawl". Like other sunbelt cities, El Paso grapples with its sprawl.El Paso is now served by bus rapid transit. We may get an update as to how the region and city are reacting to the BRIO service.When Fort Worth turned down the possibility of a streetcar, the bus service that has followed may not be where residents need it to be.In 2015 Fort Worth signed on to be a part of the Blue Zones Project, aimed to promote healthier lifestyles and increase health of residents. Fort Worth is the largest city to sign on to this initiative.Fort Worth's Mayor, Betsy Price, was featured on Fox Business, highlighting her "rolling town hall meetings", where Price encourages "city residents to participate in their local government while getting active."Austin recently approved changes to the city's accessory dwelling units, opening the possibility to more housing.Austin's rapid growth comes with traffic. And more roads. But is more pavement the answer? Some suggest that there's no place to go but up. Austin's growth and resolve to be one of the most efficient cities in terms of emissions and waste poses a great challenge in the future.Parking minimums in Austin are posing challenges to providing affordable housing, especially for student housing near the University of Texas. Will parking minimums in increasingly urban areas be reassessed?As Austin changes, some are embracing that change, and others oppose it. The YIMBY crowd is growing in Austin.As some in Dallas have fought highway expansion, other parts are preparing for it.While Houston has been celebrated for METRO's New Bus System, others around the country are taking notice, including Dallas.I'm sure parking minimums will be brought up. Dallas and Houston are likely the leading candidates for that topic of discussion.Dallas has boasted an increase in downtown apartment construction, even claiming to out-pace apartment construction in Downtown Houston.San Antonio continues to add residents to its urban core, including affordable, workforce housing. Major developments, like the Pearl Brewery, are boosting tourism.With all this growth, dog parks are inevitable. Residents are crowdfunding to build one in San Antonio's Maverick Park.Will the city's continued annexation policies be something it can afford? The city's police union says the department and the city are not equipped to provide service to an increasingly growing area.As the urban core of San Antonio grows, the city's transit agency, VIA, is looking to change several of its routes, better connecting major destinations.The Great American Cooking Story "explores urban change through the lens of restaurant owners in the heart of neighborhoods that are in varying degrees of revitalization." San Antonio is featured.Plan Houston was recently approved and adopted by Houston City Council. This is the city's first general plan.Houston's METRO agency adopted a new bus network in 2015.  The result was more frequent routes covering a larger portion of the city. The changes have boosted ridership. Nearly 5,000 housing units have been, or are being constructed, in Downtown Houston, largely due to the Downtown Living Initiative. Some challenge that this was an opportunity to add workforce housing in the city.The City of Houston is in the process of finalizing the Houston Bike Plan. A draft plan has been released and is currently seeking public input. It's the city's first bicycle planning activity since 1993. The goal is that “By 2026, the City of Houston will be a Safer, More Accessible, Gold Level Bike-Friendly City”.Texas cities continue to grow, and there's no sign that this growth is going to slow down any time soon. Planners must continue to grow in their knowledge and understanding of cities, and how they might be able to share information that serves other cities. All of our cities have big plans, but sharing our challenges and experiences might be the biggest magic to stir us toward greater city building.Tickets will be available at the event on Friday, March 4th, but attendees may not be guaranteed lunch due to advance catering arrangements. For more information please visit the event's Eventbrite page. The event’s program and agenda can be viewed here.
STREETSBLOG USA

Highway Boondoggles: Texas State Highway 249 Extension

|
In a new report, Highway Boondoggles 2, U.S. PIRG and the Frontier Group profile the most wasteful highway projects that state DOTs are building. Today we highlight the proposed 30-mile extension of State Highway 249 in Texas, which the state DOT wants to gouge through communities that already suffer from too much air pollution.  Citing outdated traffic projections, [...]
via Houston Tomorrow

No More Road Only Bonds

|
Another road building bond failed to meet the expectations of the voters of Montgomery County and the only thing so far to emerge from the elected officials is to try again in November with another road subsidy bond but without the extension of the Woodland Parkway, according to the Houston…
STREETSBLOG USA

Another Tall Tale About Congestion From the Texas Transportation Institute

|
Photo: Texas Transportation Institute Crossposted from City Observatory. Everything is bigger in Texas — which must be why, for the past 30 years, the Texas Transportation Institute (TTI) has basically cornered the market for telling whoppers about the supposed toll that traffic congestion takes on the nation’s economy. Today, they’re back with a new report, “The Urban Mobility Scorecard,” which [...]