The present relationship between cities and automobiles represents, in short, one of those jokes that history sometimes plays on progress. The interval of the automobile’s development as every day transportation has corresponded precisely with the interval during which the ideal of the suburbanized anti-city was developed architecturally, sociologically, legislatively and financially.

But automobiles are hardly inherent destroyers of cities. If we would stop telling ourselves fairy tales about the suitability and charm of nineteenth-century streets for horse-and-buggy traffic, we would see that the internal combustion engine, as it came on the scene, was potentially an excellent instrument for abetting city intensity, and at the same time for liberating cities from one of their noxious liabilities.

Not only are automotive engines quieter and cleaner than horses but, even more important, fewer engines than horses can do a given amount of work. [..] At the turn of the century, railroads had already long demonstrated that iron horses are fine instruments for reconciling concentration and movement. Automobiles, including trucks, offered, for places railroads could not go, and for jobs railroads could not do, another means of cutting down the immemorial vehicular congestion of cities.

We went awry by replacing, in effect, each horse on the crowded city streets with half a dozen or so mechanized vehicles instead of using each mechanized vehicle to replace half a dozen or so horses.

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