Well, I am pretty sure that boats left the Port of New Orleans for safer areas north. I imagine some people could have been put aboard those.
The most practical was the suggestion of bus lanes with busses picking people up at designated points. Trains could also have been used.
But we didn't see any of this, did we? Nope. The plan for the poor was NO PLAN.
Speaking as a Floridian, wouldn't it ultimately be my fault alone if I didn't have the sense to plan my own procedures deal with what are well-known "facts of life" down here, such as fire ants, alligators, water moccasins, exotic imported pests, deer flies, chiggers, wasps, termites, eastern diamondbacks, rabid raccoons, visiting liberal-voting crabby New York city folk, falling coconuts, plumetting pine limbs, 25 lb palm boots crashing down, spring breakers, rip tides, red tide, sting rays, sharks, dry season forest fires, heavy wet season flooding, Janet Reno, sunburn, intense summer heat, humidity, incredible lightning, fishy seagull poop, and things like hurricane season storm surges, winds, and flying debris?
As you can tell, I'm not a realtor.