2/n n.b. re: history of traffic calming, recall William Bunge's map of injury from automobile accidents in the 1960s Detroit; an earlier version of the map was bluntly entitled 'Where Commuters Run over Black Children on the Pointes-Downtown Track' (image @Cornell Library)

3/n and yes, I suppose if it's true that the rich bought into calmed areas that would be different from the emergent process of prosperity being marginally separate from poverty the late 19thc Booth maps show. See my blog posts, e.g. https://urbanformation.wordpress.com/2018/08/06/the-narrow-streets-and-meaner-houses-of-soho-in-19th-century-london/, though ...

4/n ... though: one must take care to not generalise. If permeability is maintained to the interior of calmed neighbourhoods, especially if walking to amenities is maintained, could be a positive plan.