You are correct PAR35. You can get 10,000 to 15,000 out with about 100 modern passenger cars...enough to empty the Superdome in two or three round trips.
Where would they go? Lake Charles...perhaps Beaumont. Wouldn't get them ENTIRELY out of the storms path....but both locations should be much better off than NO.
As for shelters, the usual: gymns, churches, warehouses, Sam's Club, Costco...
I am guessing letting that crowd in Sams Club would be a bad decision.
I'll concede that anyplace is better than NO at this point, but at the time they would have needed to start the process, there was some risk that it could hit west of where it is going to - meaning that you might be moving folks into the path of danger. (But, of course not as bad as it is looking like it will turn out.)
The second problem is that it is my guess that the shelters will be packed by folks who got themselves there. I'll try to remember to check tomorrow to see what reports are on that.
To make my position clear, however, let me say that I do agree that the mayor and the governor were way behind the curve on getting things started.