Thursday, September 10, 2009

Sprawl is Still Bad, Regardless of the Measure

The National Academy of Sciences released a report this month entitled Driving and the Built Environment: The Effects of Compact Development on Motorized Travel, Energy Use, and CO2 Emissions -- Special Report 298. A summary of the report can be downloaded from the Transportation Research Board.

Interestingly, this article was reported by Technology Review, under the title Forget Curbing Suburban Sprawl.
They report that "urban planners hoping to help mitigate CO2 emissions by increasing housing density would do better to focus on fuel-efficiency improvements to vehicles, investments in renewable energy, and cap and trade legislation now being voted on in Congress, according to the study, released Tuesday. It concludes that increasing population density in metropolitan areas would yield insignificant CO2 reductions."

They go on to further report that "even if 75 percent of all new and replacement housing in America were built at twice the density of current new developments, and those living in the newly constructed housing drove 25 percent less as a result, CO2 emissions from personal travel would decline nationwide by only 8 to 11 percent by 2050, according to the study. If just 25 percent of housing units were developed at such densities and residents drove only 12 percent less as a result, CO2 emissions would be reduced by less than 2 percent by 2050."

So should we go ahead and throw in the towel? Has all this advocacy for improving our built environment been for naught? Absolutely not. In fact, the evidence to change our built environment and offer more urban solutions has never been more necessary.

The two principal recommendations of the report were that:
  1. Policies that support more compact, mixed-use development and reinforce its ability to reduce VMT, energy use, and CO2 emissions should be encouraged.
  2. More carefully designed studies of the effects of land use patterns and the form and location of more compact, mixed-use development on VMT, energy use, and CO2 emissions are needed to implement compact development more effectively.

As if reducing greenhouse gas emissions was the only reason to encourage more compact, mixed-use development. And, in fact, the report notes that there are plenty of other excellent reasons to change our development patterns.
Changes in development patterns entail other benefits and costs that have not been quantified in this study.
On the benefit side, more compact, mixed-use development should reduce some infrastructure costs, increase the feasibility and cost-effectiveness of public transit, and expand housing choices where compact developments are undersupplied. Other benefits include less conversion of agricultural and other environmentally fragile areas and greater opportunities for physical activity by facilitating the use of non-motorized modes of travel, such as walking and bicycling.

And never mind the fact that the changing demographics over the past 40 years are radically changing the face of housing. Lot sizes have been in decline for decades based largely on market preferences. But if compact communities won't yield the biggest gain in GHG reductions should we just allow sprawl to perpetuate? No.

If we have learned anything from this recession it's that suburban development and its necessary dependence on leveraged debt is economically volatile at best. Suburban development patterns have also been shown to increase environmental degradation of our water supplies and our forests. The promise of the big house in the suburbs increases energy needs because of excessively high heated (and cooled) floor are per person and reduces family time due to commuting. Surburbia has shown to underperform in many ways over the last couple of decades and GHGs are only but one indicator of many.

The reason for urbanism is more than just reducing GHGs. It is because good urbanism is more resilient to changes in our future. Good urbanism provides choices in housing, in transportation, and in shopping. Sprawl limits choices. And the proposed solutions highlighted by Technology Review are expensive and untested. Urbanism, on the other hand, has a substantial track record for being adaptable. Choice is good.

1 comment:

  1. Good points made here. the other reasons for design are many especially in a time of frugality and a recessive economy. the issue of the “structural design” of this physical place and its relationship with the delivery of and the cost of public services must coincide and must be mutually understood.

    “The “cost” of a service (local government) is not set by a national or industry standard but rather by that organizations [sic] needs, wants, and political economy. While there is much that is discussed and much that is pushed either by interest groups, fed and state (admin law) as to a service standard, it is still a “local” decision as to its [sic] acceptance, level of funding, management, and service level. It is also true of the argument for the “resources” (aka the money) to carry out such standards.”

    When you put on top of this the tension between cost and revenue. Legislatures around the country, in an effort to placate the National Honmebuilders Associations, and the other parts of the economy that makes it nut from surburban sprawl, have capped local tax rates. They have also shifled the capital structure of government to elastic tax structures such as sales taxes and permit fees. All of which are gone for a substantial period of time.

    In a recent paper, i proposed that the cost of delivering services in a suburban enviornment was high. It will get higher if we do not take the opportunitty to retro-fit our communitties and rethink what is most important in the delivery of public services.

    When considering the cost of services, I believe it necessary to consider the following:

    a. The Variables. Those issues such as level of service, delivery method, prioritization of services, need v. want of services, and the resources available for such, the likes of capital, labor, and land.
    b. Management of the Services. This includes tangible and intangible things such as costs (tangible) and the cost of not doing (intangible). Also, issues such as overlap, integration, work systems, liabilities, results, and the customers and investors perspectives in the management of these services. The numerator in the equation
    c. Policy Direction or more specific, the Politics. Where do the elected officials wish to take the organization? The answers to this are as varied, many, and eclectic as your mind is now thinking.
    d. The Denominator in the equation is the number of units served. The number of units that your fixed costs are spread over. This also includes the type of units served, their location, and most importantly, the structural design of the community that the unit is located in.

    in our effort to create…a coherent and supportive physical framework”
    (CNU, Charter), we need to remember the elephant in the room is density. It leads me to surmise that density is a percieved value. It is also extreme in nature. Its mean and outliers are so far apart as to create very terse versions in our own minds as to what is acceptable in the realm of public policy. It is also a dependent variable. It is dependent upon the infrastrucure that serves it and the division of labor that can be derived from it. It also depends upon trade with other markets and the way in which these markets connect to each other (water and land were the trade routes of the day. the United States of course had this and with the invention of rail, then the combustion engine and a lot of untamed land in between, the USA could afford to be autarkratic).

    What should be our expectations from our current paradigm shift? Let me propose that it is this: “To a Redevelopment strategy --- to a public policy of Retrofitting Suburbia --- to a Market driven coordination of the economy ---to the truing up of the cost of the public good --- to conservation as a public good ---to sustainability as an outcome --- to a sense of place.”

    Scott Dadson, Beaufort,SC