It is both possible and feasible to drive in the old parts of the city. It is a North American city, so old is not that old. It just predates the automobile. Yet virtually all of the roads are plenty wide for two lane traffic, on street parking and sidewalks. What differs most significantly is land use patterns. More stuff (homes, businesses, schools, parks, etc.) are within walking distance. One could argue that parking is problematic, but that is true of the core of every city I've been in. Even the modern car-centric ones. It should also be noted that plenty of people drive in the old parts of the city, it's just that people have an opportunity not to and plenty of people choose not to.

In many places where I’ve lived people walk just for fun, because it’s enjoyable activity.