The NYTimes hosted an online roundtable about the possibility of going car-free in America. Witold Rybczynski's entry contained one interesting note.
There are only six American downtown districts that are dense enough to support mass transit, which you need if you’re going to be carless: New York City (Midtown and Downtown), Chicago, Philadelphia, Boston and San Francisco. That’s it. The breaking-point for density and mass transit feasibility seems to be about 50 persons per acre, which means families living in flats and apartments, rather than single-family houses, even row houses. Not necessarily high-rise apartments, but at least walk-ups.
Since most Americans still prefer living in houses, this is a problem — at least as far as carlessness is concerned. A more realistic goal for most Americans would be a semi-carless community, that is, one that is walkable within the neighborhood for convenience shopping, school-going and errands, and drivable for weekly shopping, consumer purchases and so on. A combination of twins, townhouses and low-rise apartments. Think of it as a halfway house.
It is sad to not see LA listed among those, but I've long since resigned myself to the necessity of a car in this town.
Marc Schlossberg chimes in:
The goal should not be car-free, but car-appropriate. The car was a wonderful invention: door-to-door travel, in relative comfort, at the time of one’s choice. The costs of using the car for every type of trip, however, are finally apparent, from their contribution to global climate change, the national obesity epidemic from loss of daily physical activity and the 40,000 deaths per year on the roadways, to the social isolation and neighborhood fragmentation that the roadway system creates. The way forward is not to eliminate cars, but to relegate them to the tasks they do well.
He goes on to describe ways to minimize car use, the most interesting of which is to reduce availability of parking (after making walking a more viable option).