Hey, I feel your pain. My hometown (Pittsburgh) actually did something similar to that. You know that the Steel City once had a very active, vibrant, yet geographically limited Chinatown? You know what all but killed that? Answer: the Boulevard of the Allies, an elevated bumper-to-bumper-traffic-infested hell... Nearby Crosstown Boulevard was no better. It established a physical boundary between Downtown and the Lower Hill, preventing those two neighborhoods from meshing rather nicely with each other...
So yeah, in some sense, seeing the rather sad state that became of Jacksonville made me think of all the backwards planning that was done where I grew up as well. As PhotoLith stated, many US cities have done this over the decades...