I can envision these pit-stops located at ten mile intervals along designated evacuation routes. Lots of space to handle many cars, lots of gas pumps. Entrances as wide as toll plazas. Plenty of ice, water, and restrooms. Normally, they are shut down, and they come into play only during an evacuation.
Of course, the logistics of how to staff and stock them would need to be worked out. For example, is the gas already there, in storage, or are the tanks filled when the evac is called?
It would cost a lot to build a system of these, but then, it might be worth it in the long run, especially in the case of the larger cities.
Looks like a remnant of Rita has made its way back down over the gulf. TWC says they don't think it'll develop, but they'll keep an eye on it. Sure hope Rita doesn't do an Ivan.