Attrition [of cars], too, must operate in positive terms, as a means of supplying positive, easily understood and desired improvements, appealing to various specific and tangible city interests. This is desirable not because such an approach is a superior persuasive and political device (although it is), but because the objects should be tangible and positive objects of increasing, in specific places, city diversity vitality, and workability. To concentrate on riddance as the primary purpose, negatively to put taboos and penalties on automobiles… would be a policy not only doomed to defeat but rightly doomed to defeat.

~ Jane Jacobs, The Death and Life of Great American Cities