Car Free City !!! Is it possible?

I am a student of undergrad. That day I got a link of an internship. It's called Car Free Alliance (CCA) . I don't know why I filled that form and guess what I got the confirmation. The idea of a city without a car first chocked me. Is this even possible ? Now I am a proud intern of CCA and learning a lot of things from my mentors. It terrified me knowing that the car we are buying with our money is causing us so many trouble (ex - air pollution, sound pollution, lacking playground of our kid etc) . People have no place to have a walk safely. Now, I am working with CCA to make a better world where we will be able to have walk, our kids will be able play and so on.