If the request was in fact issued at 4am, I would bet that at least 90% of the population in the area were at home. So did they force the other 10% to stay where they were, or were they allowed to get home to their family?
Someone asked what the request accomplished, and I say it allowed them to ultimately find him without any further deaths or injuries. What if none of the transit were shut down? Maybe he gets a taxi, kills the driver and gets out of town. Or maybe he gets into the mess that is mass commuting in the downtown area and gets out, or worse, is recognized and starts shooting.
You guys talk about Alex Jones' tinfoil crap, but this seems right out of his textbook. The "good guys" probably got together and asked what would be the worst case and how can we alleviate that? The answer was shut down escape methods and get people out of the way. Big deal. This was a far stretch from even Katrina.