This needs to be part of the national emergency plan from now on. Every city with 200000+ people needs to coordinate with other cities to have a plan to absorb their entire poplulations. Each city must have a plan for what they would do for the incoming people from the affected city.
For instance, Nashville could have agreements with Atlanta, Chattanooga, Memphis, Indianapolis, Knoxville, Louisville, Birmingham, St Louis - all 4 hours or less away. Internally, Nashville could be divided into zones, and a massive education campaign could be launched to educate Nashvillians on where to go if there is an evacuation.
(I KNOW this is possible, a few years ago they had a huge advertising campaign to get people to call the normal police number instead of 911 in non-emergencies. I can tell you, every Nashvillian knows the number to call. They even turned it into a song). Signage could also be created for evacuation routes in each zone - maybe color coordinated.
This is one thing I want president Bush to do: mandate that each city come up with a plan, coordinated with nearby cities, to empty their cities in 48 hours or less. These are the times we live in. This should be the lesson of New Orleans.
The President cannot do that. Lobby your Congresscritters and your state govt.