I'm not sure you can really say that a whole city is neurodiversity-friendly...because I think neurodiversity-friendliness all comes down to individual people and places -- the populations of cities are massive, diverse, and ever-changing, and places (buildings, businesses, parks, homes -- and services, which aren't really people or places) tend to change as well.
I think it's about finding the communities (community groups, service providers, businesses, individuals) within a city where difference is accepted and accomodated -- and where a person's individual needs can be met, and their particular brand of weird/different is accepted and valued. The kind of community I'm talking about might end up happening in little geographical pockets within cities, or might be spread out -- but I think it's more likely to be spread out across the whole geographical area of a city.
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