CNU day 3
Heard lots of speakers. Not as much fun as the tours but still some good stuff.
First heard Peter Calthorpe talk about the environmental benefits of more compact development- lots of statistics about greenhouse gases emitted by compact vs. not-so-compact development. The most astonishing thing I heard, though, was a statistic not particularly related to his main topic: the "housing shortfall" (that is, the gap between likely housing demand and likely housing supply). According to some planning agency's regional projections, there will be 1.75 million new jobs in the San Francisco Bay Area by 2035, 1.25 new housing units demanded- and only 0.7 million housing units built. No wonder housing prices are so high!
The next speaker, James Howard Kunstler, took a very different perspective, arguing that because of energy shortages there won't be many new jobs or new housing over the next century or so. (A lot of his argument can be found at his blog, www.kunstler.com, or in his book, The Long Emergency). He argued that as a result, population is likely to either drop or to be redistributed away from major metro areas (both city and suburb) to small cities (100,000 or below) and agriculture.
His most interesting point was his rebuttal of the argument that lower household sizes will help cities. He pointed out that household sizes have been declining for a century (due to a decline in extended families, and later from lower birth rates) with no discernible effect on sprawl. Moreover, economic austerity may lead to bigger households as more unrelated people live together.
Then came an academic paper by Wes Marshall (a Ph.D candidate at the University of Connecticut), pointing out the variety of ways of measuring street connectivity, and discussing his study asserting that areas with grid street patterns tended to have higher levels of transit/bike/walking, and equally good safety records.
Billy Hattaway, a traffic engineer in Florida also spoke about street design, pointing out that the most accident-prone intersections were high-speed, high-traffic streets - precisely the streets that engineers now build under sprawl. Solution: more compact, slower intersections. He also suggested that street standards be based on the speed that you want people to travel on rather than on geometric standards; a street with a 35 mph speed limit should not be designed for people driving 50 mph. He is working on a "traditional neighborhood traffic manual" for Fla DOT, which should incorporate some of these ideas.
Andres Duany spoke about a regional visioning exercise he ran in rural England. He suggested that people be given clear alternatives, with some discussion of the subjective (and if possible objective) pros and cons of each. For example, in his exercise people were presented with several alternatives: continuing existing trends, greyfield/brownfield development (nice but usually not enough such land is around to meet population needs), transit-oriented development (massively densifying areas near rail lines), settlement extensions (building adjacent to existing urbanism- popular only if there's some separation between settlements to protect views of current village residents), and stand-alone new cities (OK if designed right, but had bad reputation due to disaster of English "New Towns", which were basically ugly sprawl).
Duany pointed out that participants were also shown the difference between 1900-30 development and postwar development. He also mentioned retrofitting by eliminating front setbacks; the advantage of this was that people can have a chance to improve their houses in ways visible to the public, thus making property more valuable.
Then I went to a discussion of the Stapleton trip (see yesterday's blog post); a couple of participants ran a survey of CNU members who went on the tour, and compared their responses to residents' responses to the same questions. Not surprisingly, residents were pretty happy with Stapleton; CNU members less so, mostly citing the considerations I mentioned (and also expressing concern that streets might be too wide, and that there wasn't enough non-park public space like libraries etc). I ran a Stapleton residential address on walkscore.com; the result was 60, OK but not great.
Then I listened to Brent Toderian, Vancouver (Canada) director of planning, talking about the "Vancouver miracle:" over the past 15 yrs or so, downtown population increased from an already healthy 45,000 to 100,000. How did he do it?
*Putting pedestrians first, then transit, then cars. No new car-oriented infrastructure or freeways. Why is this important? From an environmental perspective, walking is of course the least polluting mode of travel. Also, the major advantage of downtown living is walking, so anything that favors walking makes downtown more desirable. (In fact, he said Vancouver has no freeways).
He pointed out that walking infrastructure is "vertical as well as horizontal"- Vancouver strongly discourages blank walls, so street walls might be more appealing to pedestrians.
*Design quality. To ensure good design, all zoning is essentially discretionary; there is no entitlement to build. This strikes me as the sort of rule that might work in Vancouver, but would be incredibly toxic in a place with pro-sprawl planners and zoning boards. I also wonder how this policy would affect housing prices; I would think that it would create delay, which in turn creates expense.
*Getting families by building schools downtown. (Of course, this might not work in the USA due to issues of class, race etc). He quoted one line in a newspaper article: "When we have more than 3 kids we might have to leave downtown." Even in healthy American cities, one child is enough to move people to suburbia.
He mentioned Vancouver's "Ecodensity" plan for increasing density citywide - not through high-rises but through rowhouses, adding invisible units here and there in a variety of ways.
Finally, I listened to Gideon Berger of Denver's planning dept. talk about street design. A couple of his more interesting points:
*One downside of cul-de-sacs: arterials are intended to move regional traffic, but if there are no alternative streets to move local traffic, the local trips clog up the arterial. (Having lived half a block off an arterial and been one of the "cloggers" I can vouch for this point).
*He pointed out that the effects of mixed use depend on the corridor. He cited a study by Profs. Wachter and Gillen of Penn; in Philadelphia commercial corridors in "bad" condition, housing values are 13% lower for housing 1/4 of a mile from the commercial street, but in corridors in "excellent" condition, housing values are actually 36% higher for housing within 1/4 mile from the street (compared to housing further from the commercial street). But after looking up the study I couldn't figure out how the authors defined "good" and "bad" corridors. (The study is at www.upenn.edu/penniur/pdf/Public%20Investment%20Strategies.pdf)
Posted by lewyn
at 8:12 PM EDT
