Agenda - 08-25-2008- c2 - Laserfiche WebLink

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i ~~ organic gases', 52% of the nitrogen oxides' and 69% of carbon monoxide Z. In Los Angeles, motor vehicles and their fuels account for about 90% of the cancer risk3. These toxins, along with dumped motor oils, wash into our streams and. bays, becoming major water pollutants. Nevertheless, U.S. vehicle miles traveled (VMT) grew at well over 3 percent per year during the 1980s, and is forecast to increase another 25 percent per capita between 1990 and 2010.4' S What drove this growth and what can be done to rein it in? These questions have stimulated vigorous discussions in the transportation community. Research on How Urban Design Impacts VMT How does sprawl drive up VMT? Low density areas are designed to force residents to drive for most trips. Their zoning requires front and side yard setbacks, wide streets and two or more off- street parking places, reducing densities and separating destinations. Many suburbs prohibit sidewalks and convenient nearby markets, restaurants and other commerce. These government mandates force destinations farther apart, lengthening trips to where non-automotive modes become less viable. Contrast this with traditional cities which grew up around pedestrians, allowing residents to walk, bicycle or take transit to jobs, corner markets and other nearby commerce. They have relatively high densities: ranging from row houses on narrow lots through 3 to 4 story walk-ups to high-rise elevator apartments, condos and co-ops--at 20 to 200 households/residential acre. They are proximate to major job and shopping centers, but have their own local shopping and services, and sidewalks and other amenities to encourage walking. They have excellent access to transit. They were so complete that many residents seldom left them. These areas are now the central and adjacent areas of our older cities and some of the older suburbs. Smart growth replicates traditional city form. But can we measure the reductions in driving sufficient to provide reproducible emission credits to smart growth? Some progress is evident. In a survey of 32 major cities around the world, Peter Newman and Jeffrey Kenworthy found that the residents of American cities consumed nearly twice as much gasoline per capita as Australians, nearly four times as much as the more compact European cities and ten times that of three compact westernized Asian cities, Hong Kong, Singapore and Tokyo.s However, they lacked measurements of VMT, or data for neighborhoods rather than whole metropolitan areas, split into central cities and suburbs. Their data suggest that driving is reduced 30 percent every time density doubles. If so, sprawling suburban areas would benefit from modest increases in density. A few 3 to 5 story limited-parking condos or apartment houses replacing parking lots or other underused land along major streets could double their density, cutting household mileage 30 percent. If this relationship, a reduction in driving of 30% every time density doubles, holds up to the density of Manhattan, its families would drive only 8%, or 1/12, as much as nearby suburbanites. Travel surveys, where household residents log each trip, give more direct estimates of VMT. Newman and Kenworthy reported results of a travel survey of United Kingdom cities, which 2