I agree in part and disagree in part.
I agree that Springfield, Downtown, and San Marco are geographically close to Riverside.
I disagree with the idea that we can talk about them as one integrated "section" of town and I don't believe the only thing lacking to that integration is transportation. Even with adequate transportation, can we honestly say there's a huge demographic of people who want to hang out downtown? When we had trolley cars, yes, but now? I want to see trolley cars return as bad as I want to win the lottery and pay of my student loans and to see the Jags win the Super Bowl this year and yada yada yada. At what point does our longing for the past border on delusions of grandeur?
Furthermore, w/ regards to Charleston, Savannah, New Orleans--what makes them so great isn't necessarily geographic closeness. What makes them great is walkability. San Marco is extremely close to Riverside...but who would want to walk that? Ditto Downtown to Riverside. I've walked it--and it was terrible. No intentions of walking over the bridge, either.