Mayor and/or governor tells everyone on Sunday to get out of town. You get out of town -- and make sure your family and neighbors can get out of town, too. As someone posted here on FR a couple of days ago . . . nobody should be driving out of New Orleans with an empty seat in the car.
"...nobody should be driving out of New Orleans with an empty seat in the car."
I'd agree with that, but you realize that whole neighborhoods or apartment complexes of people in N.O. have no cars. I guess they could have walked to the interstate and hitchhiked -- if anybody would pick them up. There's just no way to evacuate 1 million people (in and outside the city) in such a short amount of time.