North America was built around the car instead of people and that was mistake that needs to be acknowledged. In some places it is. The insane support the automobile gets in urban centres is starting to change, we’re seeing more bike lanes and places for people to walk. In order to make changse last and make postive movement forward the first thing we must do is acknowledge the mistakes of the past.
Good public transport coupled with fast, safe, pleasant walking and bicycling can easily meet the need for movement within our cities. It is true that buses and streetcars do intrude on the main streets to an appreciable degree, but many streets will be entirely free of this annoyance. In the ideal case, public transport systems are constructed underground. (Ideally, transport systems should never be elevated, because of the ugliness, intrusion and noise that that causes.) This will not be practical in many existing cities because of the cost, and some burden of street traffic will have to be endured.
A more serious objection to the car-free city is the movement of freight. When building a city, it is a simple matter to arrange delivery of shipping containers to the places they are needed without impinging on streets. In existing cities, freight delivery systems will have to be arranged on a case-by-case basis. Amsterdam could, with little difficulty, deliver freight using its canal network. Cities that adopt streetcars for passenger service can use the same infrastructure to deliver freight at night.
Removing vehicles from our streets would make urban life cheaper, safer, quieter and more pleasant. Repurposed parking spaces and, in some cases, travel lanes would provide ample land for walking and cycling, plus any essential street-running public services, such as light rail, trash collection and emergency services. The surplus land can be devoted to public purposes — imagine Manhattan with sidewalks 15 feet wider and room for sidewalk cafes.