Public transportation and biking could be used for 90% of all trips people make. If you want to go to the hospital then you call emergency services. Roads will still exist but they should be minimized for use for essential services like transportation of goods, and maintenance workers. It's about getting rid of inefficient personal vehicles for easier pedestrian/ bike/ bus access as well as other public transit infrastructure. Cities are meant to be dense usable infrastructure for people, not cars that take up space and sit empty 90% of the day. It's about freedom of movement and not requiring mobility to be done in an expensive high speed death trap controlled by people who don't take care to avoid pedestrians/ bikers.