We must first remember that all cities were car-free little more than a century ago.

Not all cities responded to the advent of automobiles with the same enthusiasm as the cities of the United States. In fact, some cities never did adopt the car. Venice was unwilling to destroy itself in order to build streets wide enough for cars, and therefore has never had them except in a sliver near the mainland. The same situation exists in the Medina of Fez, Morocco, and several other North African cities. These districts are usually the most vibrant parts of their cities.

Cars were never necessary in cities, and in many respects they worked against the fundamental purpose of cities: to bring many people together in a space where social, cultural and economic synergies could develop. Because cars require so much space for movement and parking, they work against this objective — they cause cities to expand in order to provide the land cars need. Removing cars from cities would help to improve the quality of urban life.

[Why cars and cities are a bad match.]

Top Reddit comment:

Urban Planner here. You hear a lot of this kind of talk all over planning schools, in the profession, and more in public now that "urbanism" has become such a hot topic. The problem with this argument (and so many others about the "evils of the car") is that they miss out on one very key issue - context. The car was widely embraced not because it in itself was such an amazing idea (everyone's looking for that smoking gun and silver bullet), but because the automobile happened at a time when a number of things converged. 1) Cities were generally pretty dirty and unhygienic and crowded and expensive to live in, 2) rapid population growth during the beginning of the century was set to exacerbate those same problems and 3) congestion was pretty horrible and the manure left by horse drawn carriages was becoming a major environmental problem (planners at the time thought the city was doomed and that all cities would be buried in manure in a few decades time - they didn't see the car coming). The automobile allowed a number of things to happen that addressed many of the above issues. First off - getting rid of horse drawn carriages actually solved an environmental problem (who'da thunk?). The ability to travel longer distances at ones leisure allowed more sprawl (I say more because cities actually started sprawling with the introduction of flat fares on mass transit, which allowed people to live farther out), which helped to reduce the pressure on core urban areas and eased crowding. It was fine for a long time until EVERYONE started driving, and we all know what happens when everyone on Earth starts doing something together (cough climate change). So no, the car century wasn't a mistake, it was another iteration in urban development (like the horse-drawn carriage century before it). And likewise, we're heading into another period where we need another innovative solution to the problems we have created by having everyone drive. But getting everyone to walk is probably not going to do it. It works in many places that predate the invention of the car, but is much more difficult where the city grew up with the car. It's a lazy answer to a lazy assessment of a very complex problem.