Can you give an example of a such a city (other than the obvious examples of having sections of the inner core of a city where car usage is restricted, which is pretty much the norm in many older European cities)? But it doesn't make any sense to build (or even maintain) a city with roads designed for cars, then not allow them to be used for that purpose. If the roads and other car-based infrastructure were re-purposed in a way that made them clearly unsuitable for cars, again, as I said, you don't need to ban them - it just wouldn't be feasible or practical to use them for the vast majority of people.
There are lots of example and test going on. Yes old cities in Europe always had this but these zones are expanding. Barcelona Super-Blocks, Paris has a huge program, even Brugge is doing more of it, many cities in the Netherlands. In North America Montreal has been pushing forward. Even New York has done some of this, but not nearly enough.
> a city with roads designed for cars, then not allow them to be used for that purpose
Actually, walking, bikes, buses and commercial vehicles can use them just fine without personal cars being there.
You can also put stuff there, like restaurants can expand. You can make use the space in lots of different ways.
Yes eventually you want to move away from asphalt streets towards something more reasonable (and more environmentally friendly) but there is lots of things you can do on asphalt.
> it just wouldn't be feasible or practical to use them for the vast majority of people.
Actually removing cars and giving priority for walking, bicycles and public transport increases the transport capacity of the streets. Its also better for business along those streets as has been proven in study after study done on pedestrianization.
Can you give an example of a such a city (other than the obvious examples of having sections of the inner core of a city where car usage is restricted, which is pretty much the norm in many older European cities)? But it doesn't make any sense to build (or even maintain) a city with roads designed for cars, then not allow them to be used for that purpose. If the roads and other car-based infrastructure were re-purposed in a way that made them clearly unsuitable for cars, again, as I said, you don't need to ban them - it just wouldn't be feasible or practical to use them for the vast majority of people.