It didn’t happen and won’t happen.
People walking these streets will not experience the clutter of evolution that accommodates the car, ever. Car-free means no clutter, no noise, no fumes; a peaceful walk that includes only faces and voices.
These qualities can only be recreated in a Fused Grid neighbourhood (see Wikipedia) where portions of the network is solely for pedestrians.
While many old cities have forcefully adapted to the car, hill and island villages in the meditarean have escaped the need for adaptation because of the chosen site topography. They stand as reminders of what a pedetrian world was like, arduous but peaceful, free of any of the nuissances of motorized transportation.
The two pictures below show steep and stepped streets in wchic not even donkeys can be used for accessing houses; wheeled implement motorized or not are out of the question (and the picture). All movement and transport of goods hapens on foot.