Many cities are looking for ways to cut down on driving to decrease congestion and air pollution. Many are building more bike and pedestrian facilities or offering incentives to find alternative transportation. Some are taking more radical measures though and actually banning cars entirely or only allowing them in certain areas on alternate days.
Thanks to my neighbor Bob for sending me this aritcle where the BBC takes a look at the five most radical car-free city experiments, including one that actually backfired and increased the amount of driving and pollution.