I'm all for reducing the amount of cars on the road, but in many areas it's simply not practical not to own one.
I've done the math. Not owning a car at all or paying for note/gas/maintenance/insurance, and instead living in walking/cycling distance from work would require me to spend about $700/month more than I am now living 35 miles away and paying for my car expenses, and would leave me effectively stranded at work.