Interesting topic. In the Marine Corps, the standard, with 40 pound ruck, weapons, ammo, and body armor, is 3 mph with a 10 minute break every hour; 20 miles per day. Out of an 800 +/- man battalion, you'll lose approximately 30-50 Marines to twisted ankles, pulled muscles, dehydration, and spineless wonders. And these guys are extremely physically fit. The type of terrain and weather conditions never seemed to matter to commanders, the standard had to be met as the enemy won't wait on you to get to the fight. On my six man team, we'd operate with average 50-80 pound rucks (depending on who carried the radio, spare batteries, extra ammo, claymores, etc.) and, mission dependent, move an average of 10-20 miles per day to get into our area of operations, then roll into 24 hours ops for several days, then get back out. Very taxing physically, evening more taxing mentally. Your average American family is no where near that level of mental or physical conditioning. Unless a tsunami or hurricane is headed your way, or you ABSOLUTELY have no choice in the matter, I'd recommend staying put. I'm fortunate in that when I bought my property I deliberately looked for a location just close enough to a city to be decently accessible but far enough away to not be bothered, a year round running water source, abundant wild game from squirrels to a nice 8-point buck that I WILL get next season, and a few other property owners that are firm believers in looking out for each other. I'm surrounded on three sides by heavily forested private property and on the remaining side by forested conservation land. My farm road only has two access points, and the terrain is such that it can easily be closed off to outsiders, if necessary. Geographically, there are no major earthquake faults nearby, although a little one can be just as bad. The only major natural concern I have are tornadoes, but I'm prepared for those as well. From a survival standpoint, in the event of a natural or man made (short of a nuke) disaster, I don't think I'd have to bail. From a tactical standpoint, I have a readily defensible location with the ability to withstand a substantial siege for a considerable amount of time. Again, I will emphasize, I AM NOT A WHACKO running around the woods in cammies carrying an AK! After 22 years in the Corps, I sort of can't break the habit of eyeballing terrain in preparation for a fight. Old habits die hard...