Wednesday, June 6

Riding the Tide in Norfolk

Last week I had a chance to ride the Tide light rail, an addition to the transportation system in Norfolk, Virginia that's coming up on one full year of operation. We utilized the park and ride at the Newtown Road Station, at the eastern end of the line, and traveled to MacArthur Square in the center of Norfolk. Conveniently, the same day pass could be used for the ferry to Portsmouth, so we walked the two blocks down to the port and crossed the river just in time to serendipitously catch a Memorial Day parade down High Street.

It's not exactly obvious that the Tide, in its current form, would be successful. The Hampton Roads region is not terribly dense. Robert Cervero has estimated that light rail needs an average of 30 people per gross acre around the stations to be in the top quarter of cost-effective transit systems in the country. The stations along the Tide average around 5 people per gross acre. Overall public transportation ridership in the Hampton Roads area has been very much below the national average, a statistic that does not bode well for new investment. On top of this, the route defies a fairly standard rule of transit planning. A transit system ideally should have destinations at both ends, in order to maximize usage for both directions of travel. When Virginia Beach decided to opt out, it left the end of the line stranded in the middle.

Yet the service has done fairly well in terms of actual ridership. Between August 2011 and February 2012, weekday trips have average around 4,700, which significantly exceeds the initial 2,900 projection for the first year. (I wonder if ridership might be undercounted somewhat. On our way back to the parking lot, I noticed that some riders who were done for the day handed off their day pass to strangers who were just arriving.)

However, it's still several decades too early to adequately judge the Tide. Like all infrastructure, the Tide will likely shape the conditions of its own success over time. The Newtown Road station might remain a park-and-ride because of its highway access, but I can imagine a sizable parking garage being erected next door as demand grows. It's already the most popular station. Light rail shifts some burden of parking away from downtown, so that the more valuable downtown land can be redeveloped into more productive uses.

The stations in between are poised for transit-oriented development. Norfolk planners have anticipated this and specifically zoned the areas around these stations to utilize the infrastructure to its fullest extent. Neighborhood associations in the area are also supportive. Ironically, the same low densities around the stations that might have caused elected officials to think twice about the whole project could be a net benefit. There's potential.

The long-term success of the Tide will ultimately depend on its expansion to other major destinations in the region, especially the Virginia Beach oceanfront and the Norfolk Navy Base. The City of Virginia Beach seems to be warming to the idea. Their 2009 Comprehensive Plan designated most of the proposed corridor for growth, and identified light rail as a viable transportation alternative. Then, the city purchased right-of-way that could be used for the alignment in 2010. Once again, Virginia Beach will hold a referendum on light rail.  In November, voters will decide whether to use "reasonable efforts to support the financing and development of The Tide light rail into Virginia Beach."

Wednesday, May 23

Edward Murray Bassett and the Origins of Zoning

The following is a summary of and reflection on Zoning by Edward Murray Bassett, published by the National Municipal League in 1922. After writing the first comprehensive zoning ordinance for New York City six years earlier, Bassett had become the preeminent authority in the U.S. on this emerging land use tool. This is his case to cities for adopting a zoning code.

Zoning has become so ubiquitous in American cities that nobody bothers to defend the practice anymore. Steady rounds of critiques have been launched against zoning from all sides, from social justice proponents decrying exclusionary practices, to private property rights groups leveling against government intervention, to public policy academics, to urbanists and environmentalists opposed to strict separation of uses and controls on density. However, for the most part, mainstream zoning codes have been very resistant to these attacks over the years. Not much has changed, and, in fact, there are even very few general counterarguments made in defense of traditional zoning, at least that I'm aware of. It's just the way we do things.

This is why it's instructive to read an early planner who argued passionately for the creation of zoning codes. In 1922, there were only sixty codes in place in American cities, and Edward Murray Bassett made a compelling case for many more states to allow this new practice. I've pulled together the primary arguments he made in favor of zoning, many of which still apply today:

1. Cooperation yields overall larger return on investment for all property owners. This was Bassett's primary concern, one that he underscored with a number of prisoners' dilemma scenarios. For example, "In some of the larger cities a landowner in the business district is almost compelled to put up a skyscraper because if he put up a low building, his next neighbor would put up a higher one that would take advantage of his light and air." He asserted that skyscrapers were probably not a sound investment in their own right, but they were built anyway in a virtual arms race for public goods of light, air, privacy, and scenery. Zoning was the truce that made everyone better off.

2. Zoning stabilizes building and property values, by signaling to investors what they can expect from a certain district. Markets work when people know what they are buying, and zoning creates some assurance that the product will not change fundamentally. This reason is why housing developers were among the most ardent supporters of zoning in the early stages.

3. Constitutional limits on local "police powers" would prevent zoning excesses, so residents need not worry about a slippery slope toward regulating "aesthetics and sentimentality" (more on this below).

4. Zoning is better than deed-restrictions, which were already being used to accomplish a similar purpose. Unlike the latter tool, zoning is applied comprehensively and can be adjusted by elected bodies to meet evolving needs.

5. Zoning is better than nuisance law. Without a zoning code in place, disputes between property owners about impacts can only be settled through common law nuisance claims. This is more expensive and arbitrary than zoning. 

6. Zoning prevents the wealthy from leaving the city. By 1922, the trend toward suburbanization was well underway. Bassett advised cities to zone for the kinds of low-density neighborhoods the wealthy were seeking, in order to prevent them from moving further out and losing the tax base. (This is reminiscent of a contemporary argument that cities must provide free downtown parking, in order to prevent shoppers from taking their business to the suburban big boxes).

7. Zoning limits land speculation by eliminating the possibility for large-scale buildings in low-density zones. Bassett writes, “Owners of vacant corner lots, that had been held out of use so that apartment houses might be built, have in almost every case improved them as high-class one-family residences.” (ok ... I don't buy this one. There would seem to be counterexamples that go the opposite direction)

8. Zoning maximizes public infrastructure investment.  Major thoroughfares create natural businesses districts by giving access to numerous customers. However, if homes or other less suitable uses are built on major streets, the full economic impact of the public infrastructure is not achieved.

9. Zoning manages and stabilizes growth. He wrote, “Zoning encourages growth while at the same time it prevents too rapid changes.” A good code would lead to steady growth, without any expanding or deflating real estate bubbles. This would also facilitate reasonable planning of public infrastructure and facilities.

Notice the complete absence of social, moral, or ideological language. These are not the words of a utopian academic envisioning the city of the future, but rather a politically-astute pragmatist addressing a chamber of commerce or some other worldly audience. Bassett deliberately distanced himself from any "radical experimentation" even while presenting what was on the regulatory cutting edge of the time. Unlike some previous planners, he did not present zoning as a tool for class segregation. He didn't even really mention class, or housing conditions, or city beautification, or any of the other movements popular at the time. His focus was squarely on return on investment.

But Bassett issued a very interesting caution - tucked into the middle of a paragraph - that gives some insight into an appropriate purpose and scope for this tool. He advised cities not to pass zoning that explicitly forbids apartment buildings in single-family home zones, instead favoring one broad residential zone for all types of housing (he thought setback and height limitations could be used to achieve the same effect).

Bassett was certainly not worried about concentrating poverty or perpetuating sprawl, as we might be today. He was concerned that the courts would throw out such regulations as a breach of the constitutional power to protect "health, safety, morals, and general welfare." If this happened, he believed it would have a chilling effect for all cities, causing an over-reaction that could very well have killed zoning in its infancy.

We have to remember that the courts were still probing exactly how far land use regulations legally could go. As a father of a toddler, I can relate to the series of tests it takes to establish the exact meaning of something as simple as "don't smash your carrots." It took the U.S. Supreme Court decades to test the meaning of local police powers to control land use. First, the court allowed building height regulation in Boston, then setback regulation in Richmond, then regulation of industrial uses in Los Angeles. Bassett was heartened by these successes, but he didn't want to push his luck.

The Village of Euclid, Ohio passed their zoning ordinance just as Bassett published this pamphlet, leaving them without the benefit of his cautionary advice. Their ordinance did, in fact, prohibit multifamily buildings entirely from single-family districts, and the Supreme Court Justices paid special attention to this fact during the landmark Village of Euclid v. Ambler Realty Co. case. Prohibiting a smokestack next to a school is one thing, but would allowing different housing types to share a district really detract from the health, safety, or welfare of the public?

Yes, as it turns out. Bassett was wrong. The court upheld Euclid's code, thereby granting more power to zoning than he had anticipated. From the opinion of the court delivered by Justice Sutherland, at length:
"With particular reference to apartment houses, it is pointed out that the development of detached house sections is greatly retarded by the coming of apartment houses, which has sometimes resulted in destroying the entire section for private house purposes; that, in such sections, very often the apartment house is a mere parasite, constructed in order to take advantage of the open spaces and attractive surroundings created by the residential character of the district. Moreover, the coming of one apartment house is followed by others, interfering by their height and bulk with the free circulation of air and monopolizing the rays of the sun which otherwise would fall upon the smaller homes, and bringing, as their necessary accompaniments, the disturbing noises incident to increased traffic and business, and the occupation, by means of moving and parked automobiles, of larger portions of the streets, thus detracting from their safety and depriving children of the privilege of quiet and open spaces for play, enjoyed by those in more favored localities -- until, finally, the residential character of the neighborhood and its desirability as a place of detached residences are utterly destroyed."
(Of course, if you happened to live in one of those parasites that lead to a chain reaction of utter destruction, it's not clear how your own welfare is benefited by this ruling in any way.)

Euclid could easily have gone the other way. The Ohio Federal District Court previously struck down Euclid's zoning, declaring "in the last analysis, the result to be accomplished is to classify the population and segregate them according to their income or situation in life." A Euclid loss would have still allowed certain form-based regulations and limitations on industrial uses, but broader land use regulation would have been severely chastened. Bassett was probably right to doubt the odds of a victory in 1922, but the number of zoning ordinances had grown exponentially in just five years. The Justices hearing the Euclid case were reminded of the 24 million U.S. residents living under a democratically-imposed zoning code as they weighed the allowable extent of this power.

I have not been able to find Bassett's reaction to the Euclid decision, but it raises an interesting question. Was he relieved that the zoning he fought so hard for passed its most important test of constitutional scrutiny? Or was he concerned that this power was being taken too far? After all, the constitutional protection against excesses was one of his original selling points of zoning:
"Zoning must be done in relation to the public health, safety, morals and general welfare. If it is done arbitrarily or by whim or for aesthetics or for purely sentimental purposes or with unjust discrimination, the courts will not uphold it."
I'd like to think that Bassett, at least in some honest moments, felt a little like Dr. Frankenstein. He had persuasively (to me at least) argued for a community's responsibility to form some order out of chaos, only to see zoning grow to reinforce the benefit of "favored localities" at the expense of others. He wrote that zoning "should follow nature and it should not be forgotten that the city has a history," yet this tool had begun to artificially restructure the 20th century city into a form never before seen. He had expected the courts to be a bulwark against taking this power too far. But that did not happen.

Thursday, April 26

The Nature of Adaptable Housing

An older, urban townhouse in a healthy metro area: could be rented or owned.
Every region needs a certain proportion of rented homes and owned homes, and this optimal balance is constantly shifting with fluctuations in housing market demand. Right now, most areas of the U.S. find themselves correcting for years of oversupplying owner-occupied homes. A combination of demographic and financial conditions have made renting a more attractive option - or at least the only option - for many households. According to the most recent census numbers, multifamily housing starts increased by 70% between March 2012 and the year before, while single-family housing starts increased by only 18% (after falling from years before). Like warming up a bathtub by adding hot water,  new construction is one way to achieve the balance. But it's very slow and sometimes the bathtub is already full enough.

Another way to adapt is to convert the tenure of existing homes. This is the premise of the Federal Housing Finance Agency program that would sell some of the inventory of government-owned foreclosures to bidders who agree to manage them as rentals for a period of time. It's somewhat of an experiment that may or may not work as intended, but the idea is to unload the holdings, provide affordable rental opportunities, and avoid squashing what might be a recovery in home prices.

But what if homes can be built to be naturally adaptable from the outset? During the lifespan of a home, neighborhood-scaled and regionally-scaled demands will inevitable change. A long-term outlook will envision how the same structure can adapt to these conditions as needed.

It turns out that certain kinds of homes lend themselves to conversion better than others. The Housing and Urban Development agency's PD&R office just released a study of these adapting homes. Using the American Housing Survey, which has followed the same set of housing units over several decades, researchers picked out the homes that have switched between rental and ownership at least once between 1985 and 2009. There are 23.8 million of them, or 18% of the nation's housing stock. Looking at some of the other housing attributes in the survey, they were able to create a profile of the kinds of homes more likely to switch.

In order of strength of correlation:
  1. Adaptable homes tend to be townhouses or duplexes.  About three quarters of all single family detached homes are only ever owner-occupied, and the reverse is true of multifamily housing. But single-family attached homes are remarkably flexible, with 35.6% of all units adapting during this time period. Small multifamily buildings of 2-4 units also scored highly.

  2. Adaptable homes tend to be small but not that small. Two bedroom and three bedroom homes are the most likely to switch tenure. Larger homes are mostly only owned, and smaller ones tend to just be rented.

  3. Adaptable homes tend to be in central cities. In metropolitan areas, the further the home is from the center the less likely it is to have switched. Typically, outer suburban housing is only owner-occupied.

  4. Adaptable homes tend to be older.The older a home is, the more likely it is to have switched. This holds true when the analysis is confined to only homes built before 1985, when the dataset begins. The authors speculate that this could be reflecting older homes that were built to accommodate an owner and a renter on a different floor. These housing types are particularly flexible, although new homes are rarely equipped with accessory units.

  5. Adaptable homes tend to be in growing and economically healthy metropolitan areas. In metropolitan areas that grew by 5% or less over the last three decades, 22.4% had switched. That rate increases to around 30% in high-growth areas. Economically healthy cities have a greater need to absorb changes, and also tend to have a higher proportion of renters in general.
When you picture a switch happening, you might think of the conventional "trickle-down" process. An older home that has depreciated in value over the years eventually is converted to a rental unit, or maybe several, for households with less income. However, this storyline is not supported by the data. In fact, a conversion from rental to ownership is almost just as common as from ownership to rent. It should also be noted that we're not talking about housing as revolving doors of tenure. The ones that switched typically remained that way for many consecutive years.

The study did not consider a couple of major factors in adaptability - deed-restrictions and zoning ordinances. Homeowners' Associations or local governments forbid or heavily regulate rental in many residential areas, either, depending on your perspective, to promote neighborhood stability or to keep lower-income households at a distance. Since these occupancy restrictions are more common in the suburbs and among newer housing subdivisions, the correlation between these variables might be explained by such legal barriers. Either way, it's pretty clear these regulations considerably impede adaptability.

U.S. Presidents and Congress have quite openly proclaimed homeownership as the superior form of tenure for many decades, and housing policy continues to nudge families in this direction. However, in the wake of the housing market downturn, others are seeking to raise the profile of renting as a viable option in its own right. Injecting more adaptability into the housing stock will allow the succession of occupants to adjust to their own changing needs over the decades or even centuries of the home's use.

Monday, March 26

New Census Geographies Tell an Ambiguous Urban Story

The U.S. Census Bureau announced today that the U.S. population is more urbanized than ever before. In 2000, 79.0% of the population lived in an Urban Area, as defined by the Census Bureau, and in 2010 that number grew to 80.7% of all Americans. While this finding might suggest that Americans are moving into the kinds of urban places featured on this blog – walkable neighborhoods with a diversity of uses in close proximity - the full story is much more nuanced. "Urban" can mean many things.

While the urbanized population grew between 2000 and 2010, the area of land considered urbanized grew by even more. This requires some explanation of the terms. The Census determines two types of Urban Areas, using a complex set of mapping criteria based on neighborhood-scale population density, impervious surfaces, and other factors. There are “Urbanized Areas” of 50,000 people or more, and “Urban Clusters” of 2,500 people or more. These are important geographies because, unlike metropolitan areas or incorporated cities, they are based on the results of the census. They are not arbitrary lines on the map but a description of the facts on the ground.

Before looking at some results, I'd like to note that the minimum density threshold to qualify an area as urban is not all that high. An area must have core Census Tracts with at least 1,000 people per square mile, and the urbanized area can spread out indefinitely as long as there are contiguous areas with 500 people per square mile. It can even "jump" and "hop" over sparsely populated land to continue along a corridor. As a point of reference, a neighborhood of single-family houses on two acres lots would qualify as "urban" under this definition, even considering roadways and other leftover spaces.

Urbanized Areas (the cities, not the towns) increased in population by 13.3% between 2000 and 2010, but they also increased in land area by 18.5%. This means the population density of all Urbanized Areas in the United States dropped by 4.4%. This fact is particularly troubling, because Urbanized Area population densities actually increased by 1.9% between 1990 and 2000 (the methodology for computing urban areas changed considerably between 1990 and 2000, but this number comes from applying the 2000 methodology back to 1990). It’s probably more accurate to say that Americans didn’t become more urbanized in the last decade, but that we witnessed a convergence. The Urban Areas grew, but became less urban in the process.

Of course, the changes in density happened differently throughout the country, and neighborhood-scaled density arranged itself much differently inside each urban area. Here are some top ten lists from the new census geographies. In each case, density is measured in People per Square Mile for the whole Urbanized Area:

Top Ten Densest Urbanized Areas (over 50,000) in 2010

2000 Rank
Los Angeles--Long Beach--Anaheim, CA
San Francisco--Oakland, CA
San Jose, CA
Delano, CA
New York--Newark, NY--NJ--CT
Davis, CA
Lompoc, CA
Urban Honolulu, HI
Woodland, CA
Las Vegas--Henderson, NV

 The California cites remain the densest in the county by this measurement. Either because of water supply, topography, federal land, or local land-use regulations, many these cities have sharp edges that tend to maximize the density of development within the urban boundaries. We see here New York lagging behind LA in urban area density, although, as I've posted before, the average person in NY lives in a neighborhood about two and a half times as dense as the average person in LA. The scale of the density measurement will give different results.

Top Ten Decreases in Density (over 50,000) between 2000 and 2010

New Orleans, LA
Delano, CA
Woodland, CA
Port Arthur, TX
Fairfield, CA
Grand Forks, ND--MN
Lewiston, ME
Vallejo, CA
Provo--Orem, UT
San Luis Obispo, CA

New Orleans, of course, suffered dramatic population loss in the wake of hurricane Katrina, but note that the city also expanded in land area by about 25% over the decade. New Orleans was the 7th densest Urbanized Area in the country in 2000, right behind New York, but a natural disaster interacting with suburban sprawl has knocked it down to 31st, just ahead of Denver. We could be seeing the results of a different kind of disaster in some of the California cities on this list, many of which were hit hard by foreclosures. Extensive home construction over the decade may have increased the urbanized area without a corresponding increase in people to live in those houses. Provo-Orem, Utah has a much more straight-forward explanation: lots of growth, all spreading outward at very low density.

Top Ten Increases in Density among Urbanized Areas (over 50,000) between 2000 and 2010
Lompoc, CA
Sierra Vista, AZ
Santa Maria, CA
Victoria, TX
Corvallis, OR
Madera, CA
Lodi, CA
San Diego, CA
Colorado Springs, CO
Lady Lake, FL

Lompoc, CA and Sierra Vista, CA are probably flukes in the counting method. The urban areas for these places in 2000 were very odd, and the 2010 calculations show much more constricted, and probably more accurate, areas. San Diego certainly has a legitimate claim to an increase in density, but the fact that the Camp Pendleton Marine Corp base was dropped from the Urban Area between 2000 and 2010 gives it an artificial boost. The only other big cities to show notable increases in density were Portland, OR (5.6%) and Seattle (6.5%). Although it's just short of making the top ten, the population density of Charlottesville, Virginia grew by 23% over the decade to a respectable 2,672 people per square mile.

Top Ten Densest Urban Clusters (2,500 > = < 50,000) in 2010

Richgrove, CA
Parlier, CA
Mattawa, WA
San Luis, AZ
Santa Paula, CA
Mountain House, CA
Guadalupe, CA
Orange Cove, CA
Soledad, CA
Greenfield, CA

We can't forget the small towns. California towns with heavy agriculture dominate this list, and with some very high levels of density.

Now we'll leave population behind, and look just at the increasing amount of land used for human habitation.

 Top Ten Urbanized Areas (over 50,000) with Greatest Increase in Area between 2000 and 2010

% Change
Atlanta, GA
Dallas--Fort Worth--Arlington, TX
Houston, TX
Phoenix--Mesa, AZ

Chicago, IL--IN
Charlotte, NC--SC

Austin, TX
Raleigh, NC

San Antonio, TX
Philadelphia, PA--NJ--DE--MD

Maps of some selected urbanized areas paint a picture of the bookends of urban change over the decade:

Dark purple = in 2000 and 2010 urban areas
Light purple = new for 2010

Atlanta had the greatest expansion of urban land over the decade, with no less than 683 square miles of growth.

Charlotte had the fastest population growth of any urbanized area, but the expansion of land was even faster at a 70% rate of growth.

After several decades of rapid expansion, the Phoenix-Mesa urbanized area increased by another 43% between 2000 and and 2010. Atlanta had much more growth and Charlotte had a much higher growth rate, but Phoenix held it's own on both measures, perhaps adding more ammunition to those who consider this desert oasis to be the world's least sustainable city.

It was a surprise to me to see the older Philadelphia ranked as an expanding urbanized area.

The urbanized area of Austin kept pace with Dallas-Fort Worth and Houston in terms of total land growth. But it's rate of land expansion was far higher than the large Texas metropolises.

And now for some more positive news:

Dark blue = in both 2000 and 2010 urban areas
Grey = new for 2010
Light blue = in 2000, but not 2010 urban areas

All of the Bay Area urbanized areas held steady on expansion, and the urban area even shrunk in Marin County and some spots in Silicon Valley. Population growth in San Francisco-Oakland was not particularly strong, but the San Jose urbanized area grew by a moderate 8.2% over the decade.

San Diego showed little outward expansion, while absorbing an additional 282 thousand people. The official number was even negative, but the drop was caused by the removal of a military base from the urban area.

Colorado Springs is an especially interesting case. The urbanized population grew by an impressive 21% over the decade with very minimal expansion of its footprint.

This decade will remain very tricky to characterize as a whole, because of the sharp divide in development rates that struck in 2008. Because the census was taken in April of 2010 and construction always lags behind financing, most of the growth shown here probably represents the pre-recession reality of homebuilding and commercial expansion.  We only have such thorough snapshots of urban growth once per decade, so discerning the future, in this case, may come down to reading between the lines.