More People, Less Driving: The Imperative of Curbing Sprawl

Experience with case studies has made it clear to many urban planners and environmentalists that to maximize the benefits of transit investments, and to slow growth in traffic congestion, vehicle miles traveled (VMT), and carbon emissions, you have to focus on land use.

sprawlComp.jpgPhoto: Penn State.

This knowledge has begun working its way into the policymaking world, to the extent that local and state legislatures are beginning to craft rules that explicitly factor the carbon impact of land use effects into decisions about new development and infrastructure construction. In a few years time, the federal government may follow.

But there’s not as much in the way of hard studies of the effects of land use as we might like — mainly because it’s been a non-issue, so far as most of the country is concerned, for much of recent history.

Aiming to address this (and acting under a congressional mandate), the Transportation Research Board recently completed a study that has now resulted in a very large report: "Driving and the Built Environment: The Effects of Compact Development on Motorized Travel, Energy Use, and CO Emissions."

The report is actually five mini-papers, and at nearly 200 pages long it makes for a lot of reading. But the findings reported in the introduction give an idea of what it’s all about.

The authors conclude that compact development is likely to reduce VMT: "The effects of compact, mixed-use development on VMT are likely to be enhanced when this strategy is combined with other policy measures that make alternatives to driving relatively more convenient and affordable." No surprises there.

Finding No. 2 is: "The literature suggests that doubling residential density across a metropolitan area might lower household VMT by about 5 to 12 percent, and perhaps by as much as 25 percent, if coupled with higher employment concentrations, significant public transit improvements, mixed uses, and other supportive demand management measures."

They note that were you to move the residents of Atlanta to an area built like Boston, you’d lower the Atlantans’ VMT per household by perhaps 25 percent.

Better land use results in reductions in energy use and carbon emissions, the authors report, from both direct and indirect causes. (Direct causes would be a reduction in VMT; indirect include things like longer vehicle lifetimes from reduced use and the greater efficiency of smaller or multi-family housing units.)

But one of the crucial pieces of data included in the report is this:

As many as 57 million new housing units are projected to accommodate population growth and replacement housing needs by 2030, growing to between 62 and 105 million units by 2050 – a substantial net addition to the housing stock of 105.2 million in 2000.

Critics of smart growth efforts or rail and transit investments often wave off the potential gains from building differently by noting that so much of the current housing stock is of the sprawling, single-family home, auto-oriented sort. Convincing the people who currently live in such places to give that up for something different, they say, is sure to be an extremely difficult sell.

But that’s not the issue. No one is suggesting we rip down all of suburbia. Rather we, or at least I, am pointing out that between now and mid-century, the country will very nearly have to build itself all over again to accommodate population growth. In addition to the 100 million homes now in America, somewhere between 62 and 105 million more will be built.

The critical question is what the balance of that new construction will look like. The TRB report suggests that if 75 percent of this new construction is of a more compact variety, that emissions could be reduced 10 percent or more from the baseline scenario (and that is not taking into consideration the deployment of cleaner electricity generation and other potential sources of savings).

Ed Glaeser argued — and this is kind of hard to believe — that land use shifts from building high-speed rail between Dallas and Houston would not provide much in the way of benefits, since, he guessed, only 100,000 or so people in each city would move from the suburbs to the central city. But this entirely misses the point.

Houston and Dallas may each double their current housing stock between now and 2050. Where are those homes going to go, with what climate impacts? That’s the critical question.

Demographic shifts and changes in energy prices are sure to encourage some households that are currently living at low densities to move to more compact developments, and that’s a good thing. But that’s not the main reason to begin focusing on the significant available savings from smarter land use decisions.

The main reason is the growth that America will continue to face. It’s difficult to imagine that the nation can double its housing stock while building in a sprawling fashion without facing major environmental costs and economic difficulties. Land use patterns will need to change. And as this report documents, there will be considerable advantages to facilitating that change.

  • garyg

    How you think that report supports the idea that curbing sprawl is a realistic and effective strategy for reducing emissions and energy use I have no idea. The report’s MOST OPTIMISTIC scenario, requiring a dramatic change from current development practises (a doubling of the current density for 75% of new housing and development) is projected to reduce household VMT and associated fuel use and CO2 emissions by only between 8 and 11 per cent after 40 years. Transportation accounts for only about a third of total energy use and emissions in the United States. And passenger transportation accounts for only part of total transportation emissions. So in terms of total energy savings and total CO2 emissions, you’re talking about savings of just a few percentage points. Again, that’s for the most optimistic scenario. The “moderate” scenario projects reductions in household VMT, energy use and emissions of just 1.3% to 1.7% by 2050. Which would mean a reduction in total emissions of only a fraction of one per cent. How is this a meaningful way to reduce energy consumption and carbon emissions? Even dramatic changes from current land use practises would yield only trivial savings in consumption and emissions.

  • So you’re saying Gary that there is only one silver bullet to reducing GHG emissions? You mean that just because 10% or 1.5% or however many percent is trivial we should just not try? This isn’t an issue of VMT alone, this is an issue of houshold budgets. If we’re reducing VMT we’re reducing costs to families. If we’re reducing VMT via this scenario we’re reducing land consumption and the cost of infrastructure. If we’re reducing VMT via this scenario we’re reducing water consumption, something desperately needed in many regions feeling the droughts. While the report looked at VMT as an issue in terms of GHGs. There are so many other issues that it addresses, it’s hard to just look at one thing and say its not worth it.

  • garyg

    I’m saying that, on the basis of this report, and pretty much every other study I have seen on the issue, densification is not a plausible way of achieving meaningful reductions in energy consumption and emissions. It would take a huge increase in density to achieve just a very small benefit. Increasing average automobile fuel efficiency by just 10% would do as much to reduce energy consumption and emissions as the report’s most optimistic scenario for densification.

  • I have to say I was disappointed with the report. In trying to be realistic, they set the bar very low. For example, in Atlanta “doubling density” would reducing median lot size from 0.58 acres to 0.29 acres. They basically said most of the country wouldn’t accept the type of planning that’s been fairly successful in Arlington, VA, and Portland, OR.

    garyg, cars are the crux of the issue, but it’s not what you think. If we keep building on half-acre lots (or even third-acre lots) then VMTs will have to keep increasing. If we build complete walkable/bikeable communities, people won’t have to use their cars nearly as much.

  • garyg

    They basically said most of the country wouldn’t accept the type of planning that’s been fairly successful in Arlington, VA, and Portland, OR.

    It’s not a matter of what most of the country would “accept” (whatever that means). It’s a matter of what most of the country prefers. If most people prefer Arlington-type development to conventional suburban/exurban development, why is Arlington-type development so rare?

  • Oh come now, Garyg, surely you don’t believe that this is a perfect democracy?

    You’ve made statements along the lines that “five percent” of people like walkable urban living. Even if you’re right and it’s only five percent, why aren’t there five percent of towns in the country where walkable lifestyles are privileged?

  • garyg

    Oh come now, Garyg, surely you don’t believe that this is a perfect democracy?

    I don’t believe this is a “perfect” democracy. You seem to think our democracy is not merely imperfect, but so fundamentally broken that it fails to represent the will of the people even approximately. I ask again, if most people prefer Arlington-type development, why is it so rare? What is preventing most people from using the political process to produce the kind of land use and transportation policies they prefer? What is preventing the housing and transportation markets from delivering the kind of housing and transportation that most people prefer? What evidence is there that the housing and transportation we actually have is grossly inconsistent with the preferences of most people?

    You’ve made statements along the lines that “five percent” of people like walkable urban living

    I have? Where? Show me the post.

  • I ask again, if most people prefer Arlington-type development, why is it so rare? What is preventing most people from using the political process to produce the kind of land use and transportation policies they prefer? What is preventing the housing and transportation markets from delivering the kind of housing and transportation that most people prefer? What evidence is there that the housing and transportation we actually have is grossly inconsistent with the preferences of most people?

    Do you actually, you know, read Streetsblog, or do you just scan for statements that you think you can debunk with your awesome insight into the American people’s lifestyle choices?

  • garyg

    You didn’t answer any of the questions, cap.

  • Kaja

    *eats popcorn*

  • You didn’t answer any of the questions, cap.

    Oh, but I did.

  • garyg

    If you think so, good for you.

  • HamTech87

    I didn’t read the report — just the article — so apologies if this point was made.

    One objection to more development that I didn’t read mentioned is the property/school tax impact of increased density.

    My village (a near-suburb of New York City) is revising its zoning code. A big objection to rezoning for more density is that it would bring about more residents of the town, and that means more kids in the schools. More kids means a tax increase — and a school bond issuance — to build more classrooms to fit these kids.

    To keep taxes as-is, village residents can zone for the existing density, thus preventing denser building, and shunt population growth to the exurbs.

    I don’t like this solution, but it is tough to argue against when the bottom line for most of my village’s residents is property/school taxes. I’d love to hear counter arguments that I can use. thanks.

  • Marty Barfowitz

    I ask again, if most people prefer Arlington-type development, why is it so rare? What is preventing most people from using the political process to produce the kind of land use and transportation policies they prefer?

    Oh, I don’t know, Gary but I suppose the cumulative government capital spent on highways since 1956 has a little something to do with it:

    http://www.streetsblog.org/2008/07/22/highway-funding-the-last-bastion-of-socialism-in-america/

    We’ve spent the last 70 years in this country sinking our nation’s wealth into the creation of auto-sprawlburbia. That’s not going to change overnight. It’s going to take at least another 30 years to clean up the mess.

    One thing you’ll notice about Arlington — and pretty much every other example of good urbanism in the U.S. — is that real estate prices are extremely high. And unlike the auto-oriented sprawlburbs, the real estate market in transit-oriented, walkable, bike-friendly Arlington isn’t collapsing into oblivion. These high prices suggest that the demand for good urbanism is substantial and largely unmet.

    Plenty of real estate developers have noticed. Over the last decade, private markets and public policies have started to come around to meet the demand for good urbanism. But new urbanist communities aren’t going to be erected overnight, especially when we’re building upon a legacy of 70 years-worth of planning, policy and development oriented toward the creation and growth of auto-sprawl.

    You can go to pretty much any local planning meeting in any state in the U.S. today and you’ll find great grassroots passion and energy around these issues and lots of evidence of communities trying to reclaim their communities from autosprawl. You can find examples of Americans using their local political processes to fight for better development every single day at http://www.Streetsblog.net.

  • HamTech87: You probably thought of this, but…. More residents means more taxpayers as well as more schoolchildren. The question, then, is whether newcomers would have more or fewer children than existing residents. I’m guessing that those attracted to denser development and its amenities would include a lot of singles.

  • garyg

    I suppose the cumulative government capital spent on highways since 1956 has a little something to do with it

    You’re not answering the question. How was the government able to spend so much on highways, for so long, all over the country, if most people wanted the money to be spent in some other way (mass transit, compact development, etc.)? We live in democracy, not a dictatorship. Taxing and spending is controlled by the political process.

    That’s not going to change overnight. It’s going to take at least another 30 years to clean up the mess.

    Why do you think it’s going to change substantially at all? The advantages of cars and low density development that made them attractive to people 50 years ago are still advantages today.

    And unlike the auto-oriented sprawlburbs, the real estate market in transit-oriented, walkable, bike-friendly Arlington isn’t collapsing into oblivion. These high prices suggest that the demand for good urbanism is substantial and largely unmet.

    The market for auto-oriented sprawl is not “collapsing into oblivion.” The most recent data suggests that real estate prices in general are starting to rise again. You’re confusing a short-term bubble with a long-term trend. And prices in Arlington were also subject to the bubble.

    And yes, there is obviously a significant grassroots movement for a shift towards transit, compact development, “smart growth,” etc. The streetsblog network is one illustration of that movement. But there’s no evidence that this movement is representative of the preferences of Americans in general. It’s not enough to have a small, passionate group of people. You need numbers. You need Americans in general to buy in to your arguments, and I just don’t see any serious evidence that they are.

  • Gary’s overstating the degree to which American politics is a ‘democracy’, or to which it’s controlled by a proletarian political process. It’s really controlled by factions (‘interest groups’) who’re able to sell their own interests as identical with the interests of the nation at large (‘what’s good for General Motors is good for America’). None of this looks like a conspiracy when it happens; and after the fact it’s maintained by inertia alone.

    Secondly, yes, by and large Americans do love automobiles, and are quite willing to burn nonrenewable fossil fuels to keep driving them. We’re a future-directed people who care not a whit for the futures after our own deaths.

    Though the ‘highway-motor complex’ is by no means a product of democracy, it _does_ have the tacit consent of the population.

    Centuries hence, I’d wager that middle to late twentieth century Americans are the most reviled people in all of the history of the world. We’ll deserve the hate.

  • > Taxing and spending is controlled by the political process.

    Also strictly-speaking this isn’t true either. The Highway Trust Fund is specifically removed from the political process so that politicians can’t be accused of favoritism in road-placement.

    Design decisions are the sole domain of traffic engineers, it’s funded automatically via various taxes, and it directly benefits, via contracts, dozens of industries in hundreds of congressional districts. (See also: Defense Department contractors.)

    The initial draft of the Interstate Highway System proposal failed because it was subject to political process, and Congressmen thus saw it as a liability. The 1956 revision established an independent ‘scientific’ body for which Congress could take only credit, never blame.

    It has been running on autopilot since 1956, with our tacit consent alone.

  • garyg

    Kaja,

    If you seriously believe that transportation and land use policy, including policy governing the funding of highways, cannot be substantially altered through the political process, because it is controlled by entrenched “factions” that are immune to the forces of democracy, and that the “highway-motor complex” has the “tacit consent of the population” anyway, I’m not sure why you think the alternative policies you apparrently favor (mass transit, compact development, walkable neighborhoods, “smart growth,” etc.) have a chance of prevailing except in rare and isolated cases such as Arlington.

  • So Garyg, if you seriously believe that the vast majority of the American public wants sprawl and highways, and the political process fairly reflects that, then why do you care what we write about on this blog?

  • garyg

    I think bad arguments and false claims of fact shouldn’t go unchallenged.

    Ryan Avent claims that curbing sprawl is an “imperative.” Yet the report he cites in this post to support that claim concludes that even a dramatic curbing of sprawl would produce only very minor benefits from energy and emissions savings.

  • Ah, but the Internet is full of bad arguments and false claims of fact. If Streetsblog is so inconsequential, why do you find the ones you see here so much more compelling than, say, those on a Battlestar Galactica fan blog, or a Thai cooking discussion board?

  • garyg

    I think land use and transportation are important areas of public policy and modern life, and I’m interested in them.

  • Okay, so if people aren’t going to buy into our arguments about mass transit, walking and cycling, why are you hanging out with us? Why not post where the influential people are?

  • garyg, I have no doubt that a large number of Americans like low density housing; Leinberger puts it at around 50 percent, though I think a lot of people have flexible preferences:

    http://www.infrastructurist.com/2009/02/10/how-to-save-the-suburbs-an-interview-with-christopher-leinberger/

    The problem is that there has been little flexibility in planning. It’s almost all low density, car-depended single use: tract housing and big box stores.

  • garyg

    cap,

    Because you, unfortunately, are buying into them.

    JDF,

    I think Leinberger’s claim about what people want is just wishful thinking on his part. What matters is how people act in the real world, not what they tell a pollster they would like in the abstract during a 5-minute phone call. “Walkable urban arrangements” may sound attractive to many people until they see how much more they would have to pay for housing under such arrangements and how much more difficult it would be to get around.

  • cap,

    Because you, unfortunately, are buying into them.

    Oh, Garyg, you’re doing all this for me? I had no idea you still cared. That night seems so long ago!

  • > I’m not sure why you think the alternative policies you apparrently favor (mass transit, compact development, walkable neighborhoods, “smart growth,” etc.) have a chance of prevailing

    I don’t.

    America will continue to do the wrong thing until it’s either too late, or almost too late. I’m betting on ~2025 for the wake-up, and I’d love to be pleasantly surprised.

    Meanwhile, you’re still wrong.

  • Eon

    >>>>>I think Leinberger’s claim about what people want is just wishful thinking on his part. What matters is how people act in the real world, not what they tell a pollster they would like in the abstract during a 5-minute phone call. “Walkable urban arrangements” may sound attractive to many people until they see how much more they would have to pay for housing under such arrangements and how much more difficult it would be to get around.

    How much they would have to pay???? I’m confused!!!!

    Places like Lincoln Park (Chicago), Back Bay (Boston), the East Village (NYC) and North Beach (San Fran) are exactly what people do NOT want. The supply of such places is LARGER than the demand-or developers would build more of them.

    Since these places are so massively unpopular, people would have to pay very little to live in them!!!!

    Wow, these must be the cheapest neighborhoods in America.

    Wait a minute…Why am I paying an enormous, enormous, enormous premium to live in a cheap neighborhood?

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