Well, I have thought about that for a long time, and this is more survivalist than survival talk, but I guess one can naturally lead to the other in extreme situations.

Given my economic situation, my limitations are that were I to need to evacuate my primary residence, I can go about as far as a tank of gas can take me, about as quickly as my vehcile will drive down the road unimpeded. About the only thing I can think of worth abandoning my home for would be imminent catastrophe, like mass invasion, chemical weapon spill (I have a chem demil plant in operation 35 miles south of me) radioactive release (I have a nuclear reservation 30 miles north of me) or strategic nuclear attack. In all cases, the chances I can escape the threat are not too good, but I think I've improved my odds better than 99% of those around me. I have picked 4 routes in different directions to different destinations that will not have traffic on them and provide me with shelter opportunites along the way should the need arise. 3 of my destinations are fortified and stocked, with reliable water sources and fairly isolated.

That is about the best I can do. It doesn't improve the odds much, and only addresses a minute survival aspect, but it was something to consider, and chance favors the prepared mind.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)