These are car-free public places. (Full list at Wikipedia.) Spot the connection:
Vienna (A) – old city centre
Salzburg (A) – a number of streets in the medieval centre
Bruges (B) – centre of medieval town
Freiburg im Breisgau – centre of medieval university town
Venice (I) – entire city; medieval city focused on tourism
Málaga (E) – car-free historic areas
Oxford (GB) – areas in city centre; medieval university town.
York (GB) – medieval university town; streets in centre too narrow for cars
Dubrovnik (HR) – old walled city nearly car-free
Fes el Bali (MA) – entire medina of Fes; nearly intact medieval city.
Louvain-la-Neuve (B) – university town; streets and parking below pedestrian streets
Cambridge (GB) – university town with heavy tourism
Rottnest Island (AUS) – tourist island; no cars allowed
It appears it’s easiest to justify putting a kybosh on cars in old, touristy and possibly university areas. Can you think of a place where this isn’t the case?
(Cars and narrow old streets don’t mix happily; the old sections of town are usually more compact, tourists find cars an eyesore and exhaust fumes offputting; and hundreds of students on fast and cheap bikes every day deters traffic.)
The moral of this story: if your town doesn’t fit the trend already, aim to highlight any historical or aesthetic aspects, bring in more tourists, make the roads narrower and districts more compact, and make it completely safe to get to school or college by bike.