I grew up in one of the first 'burbs outside of Pittsburgh. Public Transportation killed it.
See #11.
I live in what would be called a "first suburb" outside of Boston, and good public transit has led to gentrification. The people who lived here when it was a slum hate us, but we've kept the houses from falling apart and the tax base from melting away.
It's kind of weird to group old working class cities with old suburbs, but I guess they have similar social dynamics. There has been a lot of crossover as working-class people aspire to cape cod houses on 1/4 of an acre a little further out and professionals like me like multi-family houses on 1/10 of an acre very close to work.
I drove in to the office today. It took me 10 minutes.