Urban Planning Research

(C) The August/September 2007 Planning magazine is focused on planning issues in climate change, and is captioned, "Global warming: What you can do about it." It is all useful reading but the article that first caught my eye was Frank, Kavage, and Appleyards', "The Urban Form and Climate Change Gamble." Feeling lucky today?

The first section is a quick, clear review of the policy setting: There are international and national initiatives of uneven design and effectiveness, but the state of California recently enacted the promising California Global Warming Solutions Act (the basis for the San Bernardino suit above), setting targets and associated caps for greenhouse gas emissions. The essay then focuses on transportation as a problem source, accounting as it does for perhaps a third of CO2 emissions in the US, and the fastest growing source at that.


So, what to do about cars and drivers? The candidate policy levers include "better fuel technology, increased vehicle economy, and reducing travel demand." (p. 21) By far, most progress in relieving car pollution to date resulted from technological fixes. However, the authors calculate that this approach will no longer do the trick. Basically, new cars are already super clean yet VMT will continue to climb with population and trip-generation growth. It is thus not surprising to hear that any reasonable strategy to cut car-generated greenhouse gases in Puget Sound, their case region, must involve substantially less car travel. Indeed, even if mileage grew to an average of 75mpg, the target emission level for 2050 would require that per capita VMT fall by 20%.

Can planners do that? "Demand for car travel can be decreased in several ways, including transit investments, better land-use planning and design, transportation demand management, and road pricing." (p. 21) "Pricing efforts ... and demand management strategies ... can be implemented relatively quickly compared to changes in the built environment. However, incentives and disincentives can do little to effect change on their own unless people have reasonable alternatives to driving -- such as an efficient transit system for regional travel and land-use patterns that support walking and bicycling for local trips." (p. 22, emphasis added)


So far, the article is mainly review and context. It identifies a problem. It identifies planning tools: Infrastructure planning, pricing, and land use. The article then focuses on, "Urban form and emissions," where it makes 3 points:

1. "Sprawling urban regions not only encourage automobile use--they require it. Thus many Americans rely on their cars for nearly every commute; shopping, eating, and entertainment trips; and even recreational trips to a park. In contrast, compact communities with a mix of land uses and a highly connected street network are associated with fewer vehicle miles and trips and more bycyling and walking per capita." (p. 22)
   
   
2. This result is consistent with the authors' studies of the Puget Sound region and a comparison of two Seattle area neighborhoods.
   
   
3. The next phase of their research project will address the question of, "How do alternative approaches to land development and transportation investments affect climate change?"

1. "In addition to planning for more walkable areas at the local level, urban regions should coordinate land-use and transportation planning and make substantial investments in transit service, particularly in existing centers...."
   
   
2. "Urban growth boundaries, urban service areas, distance-based impact fees, creating parking strategies, and infrastructure requirements will also help to reduce reliance on private vehicles and lower per capita carbon dioxide emissions...."
   
   
3. "The [literature] has also documented other benefits to more compact, walkable urban regions, such as reduced per capita air pollutants and lower obesity rates, which are otherwise becoming serious public health concerns." (p. 23)

(D) Whatnot:
One, my tent is pitched in the camp of climate scientist colleagues at UCLA, who say global warming is perhaps the greatest environmental threat facing the planet, and that considerable policy changes are advisable to avoid either mayhem or the associated great economic burdens of avoiding mayhem the longer we wait (per the UK's 2006 Stern report, etc.). They are reasonable, respected, credentialed people all. Indeed, I am participating in a long term project with just that aim: Moving forward, policy-wise, in the climate change debate.


Two, how discretionary land use decisions can best address global warming is virtually unknown in general, notwithstanding what the well-intentioned Frank, Kavage, and Appleyard say to the contrary. The literature is increasingly quite clear on this, whether we like it or not. Indeed, more compact, mixed development can plausibly increase VMT, congestion, and pollution, and reduce physical activity and social capital in the bargain.

I am not saying they will, just as I can't in all honesty say they won't -- only that your experience will vary, so my own advice to practitioners is to keep their eyes open and avoid generalizing from other places to theirs until they have a good grasp of how well their details fit the story. I am not skeptical of land use strategies to reduce global warming so much as sensitive to the critical details. More and better research will clarify what works and why, what doesn't and why, and how the details matter. Presenting these as settled questions invites unsophisticated design and implementation of instruments and policies, with uncertain ends. Again, the question is not whether climate change is a pressing planning problem but how best to address it.

In particular places and cases, such strategies can work with more confidence of the desired results -- requiring less luck if you will -- if done carefully, with attention to local details and behaviors. Put another way, what works in Seattle or San Francisco may be so unhelpful in San Bernardino as to be counterproductive. (For a pdf of my related recent advice to a Beijing audience -- with Chinese translation! -- on "Top 5 Challenges to Integrating Land Use and Transportation in Urban China," look among even better presentations in this conference proceeding.)

Three, what I like about these news items: AG Jerry Brown and San Bernardino are making process promises, with attention to local details, and with respect to criteria that feature what is reasonable and what is or is not definitive. While the initial comparison with Marin County was of the apples and oranges variety, this settlement asks planning to be more attentive to climate change issues, without committing to empty promises of what will or won't work. Yes, hard and fast rules are easier to implement and understand than those based on informed discretion. On the other hand, what if they are wrong?

I also very much like that the Planning article is based more on its research rather than its few idle claims. Laying the data and analysis out plainly makes it possible to confirm or refute the method and results on their merits, and clarifies to practitioners that we generally require supporting evidence. It may draw conclusions from the literature that I do not share, which thankfully gives me something to react to, and so much the better. (Perhaps the Planning editors put the kibosh on ambiguity and elaboration in order to not confuse or bore practitioners.) The article even identifies several open research questions: When was the last time a Planning magazine article did that?

The real low down is that our purpose in these studies and their presentation is to move the data and work forward, making us researchers more valuable, accessible, and transparent to practitioners. The Frank, Kavage and Appleyard essay does that, certainly. If any of the rest of us think we can do better still, go to it.