Smart growth requires more than transportation thinking

I’ve been a bit of a one-man band over the last 2-3 years, arguing that we need a second generation of smart growth theory that goes beyond thinking about land use patterns per se. 

We now know from tons of research that smart land use patterns – neighborhoods that are compact, well-located, walkable and transit-served – are critical to a sustainable future.  They conserve land and reduce driving, reducing carbon and other emissions from transportation.  But there are so many important elements of sustainability that land use patterns themselves do not reach or at least do not satisfy, from water consumption and runoff to building and infrastructure energy, to equity and more.

Yet, from where I sit, it seems that many of my fellow smart growth advocates remain stuck in a 20th-century model of smart growth, focused almost exclusively on land use and transportation.  This is partly because of what was perceived as a special opportunity in anticipation of new omnibus federal transportation legislation that was due to be enacted two years ago (but hasn't been).  Progressive philanthropy moved significant resources into transportation, and their grantees followed.  This includes NRDC, of course, and I would be the last to argue that sustainable transportation does not remain paramount to a more sustainable America.  I’m glad we’re in the game.

But it’s not enough, and that is why I am so pleased to see one of the country’s leading transportation researchers and thinkers – UC-Berkeley’s Robert Cervero – along with Cathleen Sullivan from the transportation consultancy Nelson/Nygaard Associates, call for a “greening” of transit-oriented development.  With Michael Bernick, Cervero wrote one of the first comprehensive books on TOD in 1997, and has continued to publish on the subject since.  People like me cite his research all the time.

In their new article “Green TODs,” published in Urban Land, Cervero and Sullivan argue that, while TOD is a great concept, it can be made much better for sustainability if matched with additional environmental design principles:

“A new ultra–environmentally friendly version of transit-oriented development—green TOD—is taking form in several global cities. Green TOD is a marriage of TOD and green urbanism—a combination that can yield environmental benefits beyond the sum of what either can offer individually.

“TOD helps shrink a city’s environmental footprint by reducing vehicle-miles traveled (VMT)—a direct correlate of energy consumption and tailpipe emissions. VMT declines not only from the shift of trips from auto to transit, but also replacement of auto trips to off-site destinations with on-site walking and cycling enabled by mixed land uses.

“Green urbanism reduces nontransportation energy use, emissions, water pollution, and waste production through green architecture and sustainable community design. With green urbanism, pocket parks and community gardens replace asphalt parking. Renewable energy might come from solar and wind power, as well as biofuels created from organic waste and wastewater sludge. Insulation, triple-glazed windows, airtight construction, and use of low-impact building materials further shrink the environmental footprint of green TOD.

“In combination, TOD and green urbanism can deliver a powerful punch of energy self-sufficiency, zero-waste living, and sustainable mobility.”

Among the possibilities, say the authors, are using wastewater or combustible waste to produce energy, using space saved from reduced parking demand near transit for gardens and other green infrastructure, and taking advantage of rooftops on transit stations to place solar panels.

The article, excerpted from a longer UC-Berkeley 2010 research report titled "Toward Green TODs," draws on three European examples:  the Hammarby Sjöstad redevelopment project in Stockholm (photo just above), and the Rieselfeld and Vauban districts just outside of Freiburg, Germany.  (I first wrote about Vauban here.)

Hammarby Sjöstad, a 400-acre, mixed-use project built on both sides of a tram line, has outstanding transportation performance, but so much more:

“Hammarby Sjöstad’s green urbanism is found in energy production, waste and water management, and building design . . . [C]onservation measures include extra heat insulation, on-demand ventilation, individual metering of heating and hot water use in apartments, lighting control, use of solar panels and fuel cells, reduced water flow, and low-flush toilets.

“The ecological feature of Hammarby Sjöstad that has received the most attention is the fully integrated closed-loop ecocycle model. This system recycles waste and maximizes the reuse of waste energy and materials for heating, transportation, cooking, and electricity. At each building, residents can deposit waste into vacuum tubes that transport it to remote pickup locations. This minimizes truck traffic, thereby lowering emissions, as well as allowing narrower streets and less disruption from truck traffic. Waste is also converted into energy for district heating and cooling in the form of biogas created from treated wastewater—produced in the wastewater treatment plant from digestion of organic waste sludge—and though the incineration of combustible waste. In addition, biogas is used to run buses, and biogas-powered ovens are installed in about 1,000 apartments.”

the authors write that the project has achieved a 39 percent reduction in air and water pollution and a 42 percent cut in nonrenewable energy use compared with communities in Greater Stockholm with similar household incomes.

Rieselfeld (photo at top of post) and Vauban (photo below) are both transit-oriented suburbs.  Cervero and Sullivan report that, In addition to outstanding transportation characteristics, both also generate heat and power through wood chip–fueled cogeneration plants, and employ both active (through photovoltaics) and passive solar energy (through building orientation and architecture) features.  In addition, “both have comprehensive stormwater management systems that collect rainwater, maximize permeable surfaces through parks and playgrounds, and purify runoff through the use of bioswales and other soil filtration systems.”

Of course, even these great improvements don’t explicitly reach such important sustainability issues as equity and public health.  But they are a start, getting us out of the trap of expending so much brainpower on the transportation side of sustainability that we begin to think that more efficient transportation is the only environmental objective that matters when we encourage “smart growth” or “sustainable communities.”  The fact that these additional concepts are being endorsed by researchers so respected in the transportation field will only help them gain currency, which they richly deserve.

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