Austin Contrarian: Sprawl

March 04, 2012

Strong Towns

Last Wednesday, I attended a CNU-sponsored "curbside chat" by Chuck Marohn. Chuck is one of the founders of the Strong Towns movement. He's a civil engineer so, naturally, he mostly talks about infrastructure. His basic message is that suburban sprawl seems cheap to towns and cities because the developers pay for most of the infrastructure. But that infrastructure has a finite lifespan. Eventually it must be replaced. And when the time comes to replace it, the tax revenue generated by the low-density, low-value sprawl pattern won't cover the cost.

Chuck's from a small town in Minnesota, so he has a different perspective on growth than those of us in Austin or other fast-growing places in the sunbelt. A lot of Midwestern towns and cities stopped growing, or actually began to lose people, a long time ago. They are now saddled with worn-out roads and streets, leaky water pipes, and broken sewer systems that they cannot replace without outside help. Some cities are deliberately abandoning some infrastructure, or even whole neighborhoods, because they can't cover the cost any more.

Cities like Austin should pay attention. Austin is a very young city. More than half the city was built within the last 40 years. And it will continue to add new subdivisions a rapid clip, which will hold down the average age of our infrastrcture. But eventually the growth will end or slow to a trickle, and then we'll be stuck with a lot of aging infrastructure, and, thanks to our low-density growth patterns, a high ratio of infrastructure to people.

Obviously, cities should aim to grow their existing neighborhoods. Adding people to an existing neighborhood saves the need for new infastructure and provides more bodies to pay for the existing infrastructure when it wears out.

But my main reaction while listening to Chuck was, What do you think we're going to do about it?

Austin's comprehensive plan assumes the city will add 750,000 people over the next 30 years. I think that's optimistic -- 350,000 to 400,000 is more likely, based on last decade's rate of growth. The metro area will likely add well over a million, though.

Almost all of that growth will be greenfield. There is no political will to allow the kind of upzoning that would be necessary to accommodate even a small fraction of that growth within existing neighborhoods. Consider central Austin. It added just 8,000 people between 2000 and 2010, while Austin proper added 133,000 and the metropolitan area added 450,000 people. The central city did a bit better job adding structures than people -- its housing stock expanded by 15,000 units, or roughly 12%. But the last decade was the decade of condo towers sprouting downtown, the densification of West Campus, the Triangle, Mueller, condos in East Austin, and massive greenfield development in southeast Austin. And all that development lead to a piddly net increase of 12% of the housing stock.

Don't get me wrong. I think we should let central Austin get much denser, for many reasons. Austin is lucky because people actually want to move to the central city. Lots of cities spend a lot of time and money trying to solve the problems caused by central-city flight. But given the contentiousness of last decade's development battles, I don't see Austin allowing the kind of development we need to house even 50,000 new people in the central city.

Posted at 03:59 PM in Austin, Austin development, Density, Sprawl, Stats, Urbanism | Permalink | Comments (4) | TrackBack (0)

February 22, 2010

Parking bombs

The Overhead Wire on the destruction wrought by downtown parking. The Houston photo is stunning.

I don't believe, though, that the interstate highways share equal blame with parking for the destruction of American downtowns.

I suppose I should be careful with my definition here: I mean "Given the construction of a large, nationwide network of interstate highways, the decision to route them through downtowns did not have a material impact on the health of downtowns."

The typical large American downtown before the 1930s or so developed around a rail, harbor or port. Manufacturing clumped together near the transportation hub to save the hefty cost of moving heavy things. Service and government workers -- the only inhabitants of today's downtowns -- located downtown because that's where their customers were.

This model was doomed once the country decided to build a national network of high-speed highways. It was just a matter of time before manufacturing decamped to cheaper, less congested greenfields. It didn't matter whether the highways ran around, through or under downtown -- manufacturers weren't going to pay a premium to be down the street from a rail terminal they no longer used. Downtowns were in for a radical restructuring.

Now downtowns are occupied mainly by service and government workers. More to the point, they are occupied by service and government workers who purport to service the entire metropolitan area. A downtown Houston law firm with a large oil-and-gas practice doesn't market itself just to downtown energy firms; it sells itself to firms in the Energy Corridor, too, even though they are a 10-mile drive down the Katy Freeway. It is easy to run a metropolitan-wide law practice from downtown Houston if it is easy to get to downtown Houston from any point in the metropolis. A rich network of highways (or of light rail or commuter rail lines -- nothing in this argument depends on the mode of trip) makes the central location more attractive, not less.

Note that this has nothing to do with the impact of highways on housing patterns. Highways of course have facilitated sprawl. By lowering the cost (in time) of commuting from land on the periphery of the metropolis, they make that land more attractive for residential development. But this isn't the dynamic that causes businesses to disperse. Service firms like to cluster near similar businesses, near their customers, and near their suppliers. They will do all three if they can. When they can't do all three, they must choose. The trade offs are more acute when a downtown has poor access to the rest of the metropolitan area. In the long run, downtown Austin will suffer for its inaccessibility.

Don't take any of this as an unqualified endorsement of slashing interstate highways through downtowns. They hurt property values in their immediate vicinity. They wreck the neighborhoods that are plowed under, barricaded or sundered to make room for them. But American downtowns would have experienced wrenching change even if highways hadn't been run right through them. And American downtowns would be more desolate than they are today without the highways.

Parking is another story . . . .

Posted at 11:52 PM in Blogs, Cars, trains and buses, National, Parking, Sprawl | Permalink | Comments (15) | TrackBack (0)

September 05, 2009

Is it really necessary for the federal government to introduce new market distortions?

For the reasons I just gave, I don't believe that our past subsidies to suburban development justify maintaining those investments. End them and let the chips fall where they may.

But even if reasonable people can disagree about that, I see no argument for creating new subsidies. But that is exactly what our federal government is about to do.

The FHA is a major player in the mortgage business. It insures mortgages for home buyers who otherwise would not be able to get credit or scrape together a down payment; this allows some to buy homes with as little as 3.5% down. Without the FHA guarantees, the mortgage market would be much smaller. A few years ago, its share of the market was 2.7%. This seemingly small share had an outsized effect by scooping up the biggest credit risks and reducing the risk for private mortgage insurers. In any event, its share of the market has ballooned recently: according to Friday's WSJ, its market share reached 23% in the second quarter of this year.

And now the FHA is about to adopt new rules explicitly encouraging home buyers to purchase single-family, detached housing in the suburbs rather than attached (condos) in urban cores:

Until now, almost any condo development could apply to FHA for “approved” status, therefore making FHA financing available in that development. In addition, in developments that were not approved, “spot approvals” were sometimes available for individual units. (The lender applied for an approval for the unit you wanted to buy, in spite of the development not being approved).
Following are the new guidelines: (This is not pretty, so prepare yourself)
1. There will be NO more spot approvals.
2. All development not considered primarily residential are out. For instance, a development with more than 25% of the total floor area dedicated to commercial business use is out.
3. Noise issues is a new concern, so any development within 1,000 feet of a highway, freeway, or heavily travelled road, 3,000 feet of a railroad, 1 mile of an airport, or 5 miles of a military airfield will become ineligible for approval.
4. If the property has an “unobstructed view , or is located within 2000 feet of any facility handling or storing explosive or fire prone materials, it is not insurable - we're not talking just fireworks factories here. A gas station 2 blocks away can disqualify this development.
5. Any property located within 3000 feet of a dump, landfill, or superfund site, is ineligible.
6. No more than 10% of the properties can be owned by a single investor, including builders or developers who are renting out or have not yet sold vacant units. For 2-3 unit developments, no one can own more than one unit.
7. No more than 15% of the homeowners can be more than 30 days late on their homeowner dues.
8. For new developments, at least 50% of the units must be sold prior to applying for FHA approval (valid presales include those with purchase agreement and lender validation of an approved loan in process)
9. A minimum of 50% of the units must be owner occupied or sold to owners who intend to occupy as their principal residence.
10. Projects in designated wetland and flood zones will not qualify.
11. All current condominium project approvals will be invalid (with the exception of projects approved on or after October 1, 2008) and projects must be re-approved under the new options available. Going forward, all projects will require recertification every two years.

Perhaps most insidiously, the FHA will no longer insure more than 30% of the units in a single condominium development.

I understand that the FHA has been taking large losses on its guarantees. I also understand that condominiums are riskier to insure than single-family homes. Some of these new regulations seem reasonable -- it's probably a bad idea to invest in a condominium when the condo association lacks the resources to pay for upkeep. Higher risks justify higher premiums, too.

But these new regulations seem purposely designed to push new homeowners out of dense, urban areas to the suburbs. They exclude many mixed-use developments (#2). In a central city, it is hard to find a condominium not within 1,000 feet of a highway, freeway, or heavily travelled road, 3,000 feet of a railroad, or one mile from an airport (#3). Allowing developers to tap into FHA guarantees for entire single-family subdivisions but only 30% of condominium units naturally will encourage developers to shift to single-family subdivisions. These new regulations are fundamentally anti-urban.

Even if it is somehow possible to defend our existing scheme of suburban subsidies, is it really possible to defend introducing new market distortions?

Posted at 02:52 PM in Economics, National, Regulation, Sprawl, Urbanism | Permalink | Comments (8) | TrackBack (1)

July 18, 2009

Legacy costs

Here's a thoughtful piece from Aaron Renn on an unintended consequence of the Clean Water Act. EPA mandates are forcing Cleveland to spend $5 billion to overhaul its sewer system. That's a lot of money for any city, but especially for a struggling rust-belt town. Cleveland will be forced to raise water and sewer rates dramatically, and probably a bunch of other taxes, too.

Cleveland can't go anywhere, but its residents can. (This is a city where the police and firefighters openly celebrated an Ohio Supreme Court ruling that allows them to move to the suburbs.) Renn predicts -- accurately, I think -- that the higher taxes will speed up the depopulation of Cleveland as homeowners have one more reason to move to the suburbs. In fact, the mandate will kick the city twice: Cleveland must not only raise taxes, but it will lose money that it could have spent on other improvements that would have attracted suburbanites back to the city.

Cleveland needed to make dramatic improvements in water quality; after all, this is the city whose river famously caught fire in 1969 (which itself provided much of the momentum for the Clean Water Act). But the Cuyahoga is now clean; residents fish from it, in fact. Spending another $5 billion to get that last 10% improvement is a bad use of money when Cleveland has more pressing needs. And it is counter-productive to drive residents to the suburbs to leave rotting infrastructure sitting unused in the central city.

Renn suggests that the federal government assume the cost of replacing ancient sewer systems. That might be the only solution. The federal government has no incentive to weigh costs and benefits accurately when it can simply issue a mandate. And the moral hazard risk is smaller than one might think: the city's main "crime" is being old enough to need a new sewer system.

Guarding against strategic behavior by a city is tricky anyway since, again, its residents can simply move when things get bad. Rather than stick central cities with crippling legacy costs, it makes more sense for the federal government to issue reasonable regulations and pick up the tab for unforeseen costs.

Posted at 03:43 PM in Cities, Environmentalism, National, Regulation, Sprawl | Permalink | Comments (4) | TrackBack (0)

July 17, 2009

Reburbia

Jude points to the Reburbia competition, a design competition "dedicated to re-envisioning the suburbs." From the competition website:

In a future where limited natural resources will force us to find better solutions for density and efficiency, what will become of the cul-de-sacs, cookie-cutter tract houses and generic strip malls that have long upheld the diffuse infrastructure of suburbia? How can we redirect these existing spaces to promote sustainability, walkability, and community? It’s a problem that demands a visionary design solution and we want you to create the vision!

"Visionary design" is all well and good when you're working on a blank slate, but it matters very little when you're trying to retrofit whole subdivisions. Rising energy prices might create demand for denser and more efficient suburbs someday. That doesn't mean we will get denser and more efficient suburbs, though. The obstacle will be the homeowners who like things the way they are, and there will always be lots of homeowners like that. Sure, they might agree that other homeowners should live in denser and more efficient suburbs, but they won't want their own subdivisions retrofitted with greater density, no matter how visionary the design.

As energy becomes more expensive, those who want to live closer to work or to live in smaller, more efficient apartments or condos will move. Those who stay won't want their neighborhoods to change. I don't believe that central Austin neighborhoods, for example, will ever welcome greater density in the neighborhood interiors, no matter how high land prices get. If density can't get any traction in central neighborhoods where density makes the most sense today, I don't see it ever getting any traction in suburban neighborhoods. Great design won't entice homeowners in suburban subdivisions to cancel covenants, support rezonings, and make the other hundred changes that would be necessary.

Or perhaps I'm just too pessimistic.

Posted at 12:54 AM in National, Sprawl, Urbanism | Permalink | Comments (4) | TrackBack (0)

May 31, 2009

International migration and city growth

Wendell Cox recently posted a piece on Newgeography slicing and dicing the Census Bureau's 2008 estimates of county populations and domestic migration. He tells us that:

people continue to move to the suburbs of large metropolitan areas, and away from core areas;
in 2008, large metropolitan areas' core counties experienced a net domestic loss of 314,000, and an annual average loss of 580,000 between 2001 and 2008;
net domestic migration gains were down to 192,000 in suburban counties from an average gain of 246,000 over the decade.

The story, as Wendell sees it, is that slowing domestic migration to the suburbs does not signify a flight back to the cities. Rather, it is a return to normal migration patterns -- spiking home prices between 2001 and 2007 created a domestic migration bubble as homeowners cashed out and moved to cheaper areas.

But there is another interesting phenomenon lurking in the the Census data. Even after accounting for domestic migration, demand for central counties has risen. And that rise often has been driven by international migration.

It's clear that demand for central counties has been rising if we look at changes in total population rather than just domestic migration outflows. In 36 of the 48 large metropolitan areas analyzed by Wendell, the core counties added people between 2001 and 2008. In four of the other twelve metropolitan areas, both core and suburban counties lost residents; it is hardly surprising that the core county of a declining metropolitan area will lose population. Only eight metropolitan areas fit the "flight to the suburbs" model -- an increase in suburban population and a decrease in core county population.

Some cities can thank domestic migration for the rise in their core-county populations. Austin, for example. It added 41,000 from domestic migration between 2001 and 2008, nearly 11,000 from 2007 to 2008 alone.

But the growth of other core counties has been driven by international immigration. For example, Los Angeles County lost a staggering 1,007,000 residents due to domestic migration between 2001 and 2008. Its population nevertheless grew by a total of 318,000. It more than replaced its departing residents with healthy natural growth and international immigration. The Census Bureau estimates that between July 1, 2007 and July 1, 2008, Los Angeles County lost 103,000 residents to domestic migration -- but added 87,000 from natural growth and 70,000 from international migration, a net population increase of 54,000.

The story is the same in booming Dallas. Between July 1, 1007 and July 1, 2008, Dallas County lost 19,000 residents to domestic migration, but added 20,000 from international immigration. Its international migrants replaced its departing residents one for one.

One explanation of this phenomenon is that international immigrants are outbidding existing residents. The supply of housing in central cities is relatively inelastic thanks to tighter restrictions on new construction, NIMBYism, and the generally higher cost of dense, infill construction. A central city can add only so many people in a single year. A large inflow inevitably triggers a rise in prices and a corresponding outflow.

An alternate explanation is that demand is in fact dropping for core counties, causing a decline in housing costs, which in turn is attracting less affluent international migrants. Home prices of course have dropped sharply nearly everywhere over the last year or two. But that was not the case for the preceding seven years, and the international migrant inflows did not start last year. Regardless, declining demand can't be squared with rising population. Each year, more people, not fewer, want to live in these central counties.

I suspect that core counties are relatively more attractive for international immigrants than domestic residents. Immigrants are attracted to clusters of immigrants of the same nationality; these clusters naturally develop in core counties first, and tend to be self-sustaining. Perhaps immigrants are more comfortable with a denser, central-city environment. And perhaps domestic residents have a better grasp of the opportunities that exist outside the core county.

Whatever the reason, international immigration is driving demand for many the core counties in many metropolitan areas. The recession will cause international immigration to plummet. If international immigrants have been outbidding domestic residents, then domestic migration will drop sharply. On the other hand, if domestic migration has been prompted by a distaste for central cities, the outflows will continue. We'll see.

Posted at 05:38 PM in Blogs, Cities, Sprawl, Stats | Permalink | Comments (2) | TrackBack (0)

May 28, 2009

Demand for suburbs vs demand for central cities

Americans overwhelmingly prefer suburbs. We know this because most Americans choose to settle in suburbs.

No, wait. Demand for suburbs and exurbs is collapsing; they are on their way to becoming the next slums.

Both memes are wrong, I think. The "suburbs are dying" meme is wrong because most metropolitan growth will continue to occur in the suburbs -- at least in rapidly growing metropolitan areas -- regardless of shifts in preferences. The first is wrong because rapid suburban growth doesn't tell us anything about the relative demand for suburbs and central cities.

First, rapid growth in a metropolitan area is synonymous with rapid growth in the suburbs. And it will always be that way. (The form of suburban development is a separate issue.) It is harder to add new housing in a built-out environment. Denser construction is more expensive and takes a lot longer to get built.

Take Austin. Austin's urban core had about 170,000 residents in 2000. Austin's metropolitan area added about 390,000 residents between 2000 and 2008. Even if Austin's urban core had doubled in population between 2000 and 2008, most growth had to and did occur at the metropolitan area's fringes. Of course, Austin's urban core did not double in population. It is not possible to double the density of a built-out urban core in just eight years. I'd be surprised if Austin's urban core grew by 20% between 2000 and 2008. So its suburbs necessarily have boomed, even though Austin's core is healthy and experiencing steady growth.

Ditto with cities like Dallas, Houston and Atlanta, which each added one million residents between 2000 and 2008. It would have been impossible for their central cities to add more than a small fraction of the newcomers.

But because most growth must occur in the suburbs, this growth does not alone tell us whether demand for the suburbs is growing faster than demand for the central city.

We know that demand is higher for the suburbs when the central city is losing population while the suburbs are adding population. But in thriving cities, both suburbs and central cities are adding population. The central city is simply adding population at a slower rate.

To figure out relative demand, we also have to consider prices. Because the housing supply in the central city is relatively inelastic, higher demand mainly shows up as higher prices. Because the housing supply in the suburbs is relatively elastic, higher demand mainly shows up as more subdivisions. To determine whether demand is rising more rapidly for one than the other, we have to weigh both the rate of new construction and the change in prices. And, to complicate things, we have to factor in shocks like rising gas prices and recessions; these have different impacts on the relative demand.

So determining whether demand for one is growing faster than demand for another means disentangling a complicated knot. That is a hard thing to do. A lot harder than focusing on just rising supply or rising prices.

Posted at 11:27 AM in Cities, Density, Sprawl, Stats | Permalink | Comments (21) | TrackBack (0)

March 30, 2009

Federalizing local street networks

Streetsblog has an interesting interview with John Norquist, the president of the Congress for the New Urbanism. He discusses boulevard design, highways' impact on cities, and the benefits of dense, local street networks.

He also discusses a CNU proposal to use federal funds to encourage the latter:

The first step is to allow federal funds to be used to bring street networks up to a standard of 150 intersections per square mile. So if you have a suburban sprawl kind of situation where the intersection density is like at 40 per square mile, if you have a project that’s going to bring that intersection density up to 150, then the state would be eligible for getting federal funding to go in and do that.

As much as I prefer grids to cul-de-sacs, I think this is a bad idea.

First, it’s important to distinguish between local street networks and major arterials like boulevards and highways. States and the federal government (indirectly) pay for most highways, while cities pay for most boulevards and other arterials. Norquist rightly complains that the feds have shaped highway design and location for decades. Not to mention the mix of highway and transit spending.

Local streets are different. Local street networks look like they do because cities don’t build them anymore. They instead are platted, built and paid for by subdivision developers. They don’t become public streets until dedication, when cities take title and the responsibility for maintaining them. Cities thus have privatized their grid design. We should not be surprised, then, that developers ignore spillover benefits -- especially connectivity -- when laying out their streets.

Cities do plat and build the arterial roads that link subdivisions to the rest of the city. But we can’t get intersection density by redesigning arterials. Arterials are one-dimensional; grids are two-dimensional. CNU understands that, which is why it wants federal funding for local street networks with a minimum intersection density.

I’m sure developers would be perfectly happy with CNU's proposal. It would eliminate one of their two major infrastructure costs. (The other is running connections from the subdivision to the local water, sewer and electric lines.) Developers would lose some developable lots because a dense street network needs more pavement than the minimal street networks developers build. But I’m sure developers would gladly give up 10% of their buildable lots if cities would agree to build their streets.

Do we want to abandon developer-financed local streets? Even if cities and the feds paid just part of the cost, this would be an immense expense. Most cities don't have the money. It would take billions per year -- every year -- to make a noticeable difference in city structure.

It is also a bad idea to subsidize developers and property owners. Reducing the cost of building subdivisions would get us . . . more subdivisions. If you dislike the relentless spread of single-family subdivisions, then you want developers to bear all the cost. (Actually, you should want developers to bear all their costs regardless.)

Such a subsidy could be efficient in theory if it were limited to the extra expense incurred by the developer to densify their street networks. But developers would have no incentive to disclose their true costs, and local officials could not figure that out on their own.

Finally, it is a bad idea to get the feds involved in local street design. If “incentives” meant “funding,” the feds would dictate street layout, just like they dictate highway width, turning radii, and drinking ages. Cities wouldn't use their scarce dollars to build more than the feds require. Developers certainly wouldn't. And the federal government might not do it the way you or I want it done. Suppose the feds, thanks to lobbying by property owners and developers, decided to fund only 100 intersections per square mile? Or 75? Then 100 or 75 intersections per square mile is what would get built.

There would be enormous pressure to go with less dense networks since they are cheaper. Developers would continually push for less dense networks even if the cities were footing the bill -- sacrificing 20 houses for road funding might be a good deal, but sacrificing just 10 houses would be a better deal.

So whenever someone wanted to change the rules for local street design, they'd have to run to D.C. That's worked real well in the past, right?

Posted at 11:53 AM in Cars, trains and buses, Politics, Sprawl, Urbanism, Zoning | Permalink | Comments (3) | TrackBack (0)

March 20, 2009

Panoramic sprawl

Californian Matt Jalbert has taken a stunning set of panoramic photos of California sprawl. My favorite is of this residential development in San Ramon. I cropped a tiny patch for the photo to the right, but it does not begin to do justice to Jalbert's photo.

People use "sprawl" to mean lots of different things. I suggest readers use the panoramic photo to self-administer a Rorschach test, a test to clarify your own definition: What makes this sprawl? (Or is it not?)

If you want to do it right, you have to assume you know nothing other than what's depicted within the four corners of the photo. That is, you don't know how far the development is from the nearest major employment center, or whether it's two miles or ten miles outside a major city. (Most Northern Californians know where San Ramon is, I imagine.)

So what makes it sprawl? Note it's not vulnerable to the "sprawl is sparse" criticism -- i.e., that suburban large-lot homes chew up excessive amounts of open space. This development is as dense, structurally, as an old Italian village. The houses take up almost all of the space of their lots, leaving tiny yards at best.

My take below the jump.

Continue reading "Panoramic sprawl" »

Posted at 02:26 AM in Sprawl, Urbanism, Zoning | Permalink | Comments (14) | TrackBack (0)

February 11, 2009

"Sprawl" \'sprol\ n.

The Overhead Wire asks what sprawl is. Ryan Avent gives his answer -- he uses "sprawl" to refer to neighborhood density rather than regional density. (As a stats geek, I would state it this way: "What matters is a metropolitan area's weighted density and not its standard density.")

My own thought it that it's time to retire "sprawl." This ~~little~~ 5-letter word is being forced to do too much work; it simply has too many meanings. And it might as well be a 4-letter word because it is the land-use equivalent of "asshole" -- I've told you I don't like you but I won't bother getting specific.

Here are different meanings I've seen it given: (1) peripheral development -- greenfield development at the fringe of an urban area (one variation singles out "leapfrog" development); (2) economic dispersal -- the rising cost (in both time and money) of getting from point A to point B; (3) "pod" development -- any development sharply segregating single-family, multi-family and commercial uses; (4) low-density development -- always a relative metric, of course; and (5) auto-dependent development. I'm sure there are others.

"Sprawl" literally means "to spread or develop irregularly." That best matches (1). But what makes it such a slippery word is the correlation between these definitions, which causes people to conflate one meaning with another. Peripheral growth can lengthen commutes. Virtually all new suburban development is "pod" development, and low-density development at that. And everything built more than a quarter-mile from a rail station -- virtually any suburban development -- is car-dependent, or at least car-oriented. It is therefore unsurprising that people use "sprawl" to encompass several meanings at once.

For example, Dolores Hayden in A Field Guide to Sprawl defines "sprawl" as "a process of large-scale real estate development resulting in low-density, scattered, discontinuous car-dependent construction, usually on the periphery of declining older suburbs and shrinking city centers." So she combines (1), (4) and (5), and possibly (3) as well, and throws in a jab at tract development for good measure. (Note, though, that combining meanings technically narrows the definition rather than expands it.) There are many others, of course.

But it's sloppy to mix them up. The correlation is imperfect. New Urbanist developments that mix single-family, multi-family and commercial uses into a walkable neighborhood are often built on greenfields at the periphery of urban areas and are not served by transit. Density is not a perfect proxy for urban form because pod developments are sometimes denser than traditional, walkable neighborhoods; this is one reason why places like Phoenix have a relatively high weighted density. Infill development is frequently not served by transit and consists of segregated uses. Commuting costs can rise with rising density as well as increasing geographic dispersal if the transportation infrastructure is not up to snuff.

Each of these definitions suggests a different problem. You cannot propose a solution until you have told the rest of us what problem you are trying to solve. And "sprawl" is simply too mushy to do that. If you are worried about the loss of open space, then New Urbanist greenfield development must be included within the definition of "sprawl." If you are worried about rising commuting costs, it makes no sense to include greenfield development served by mass transit. If you care about urban form -- if you hate pod development, for example -- you should include pod development whether it's core or suburban, dense or sparse. We're engaged in lots of different debates over land use but we often don't realize it because we use just one word to characterize them all.

We need to develop more precise, clinical terms to advance the discussion. Medicine, math and science (and law, more or less) define their terms precisely. People make fun of jargon, but serious disciplines need it to keep distinct ideas straight. As used today, "sprawl" is the medical equivalent of "sick." Imagine the hilarity that would ensue if doctors used "sick" as their primary term for both prostate cancer and the flu.

Define terms precisely. And don't build moral judgments into them. You can cast aspersions once everyone else knows what you're talking about.

Posted at 02:42 PM in Cities, Density, Sprawl, Urbanism, Zoning | Permalink | Comments (4) | TrackBack (0)