It's funny, because in St. Louis, MO (often considered a heavily-blighted city by outsiders) the presence of densely-occupied street parking is usually seen as a sign of wealth. Blighted areas instead have what appear to be extra-wide roads, because they are two-lane roads with space for parking -- but nobody's parking there.

Both blighted and wealthy areas are full of city lots drawn before automobiles, so nobody has much room for parking without sacrificing part of their back yard. Some wealthy people do build parking pads and garages to do this, but the alleys are so narrow that navigating something like a Cadillac SUV into a back-of-lot garage is... problematic.

Ah, good point. I guess neighborhood age is the bigger indicator than density (though they're often loosely correlated). Newer cities and burbs have driveways and garages as first-class citizens, and wealthy areas have space to spare (vs having to convert your garage to another room, etc).