I found some depressing analysis on G.O.O.D. for those of us near US population centers: Read this PDF.
For further information on the ineffectiveness of G.O.O.D. when times get bad, US DOT generated this report: Using Highways for No-Notice Evacuations.
In addition, there is no shortage at the US DOT web site of well-intentioned and theoretical research reports on disaster planning.
For many of us, last minute G.O.O.D. plans are likely to be characterized by a high probability of failure along with its associated human costs. One might guess that the chance of failure is an exponential function of the distance to the retreat. I need to remind myself that it is not a simple matter of just getting in the car or BOV and heading out to the safety of my retreat. Might work, probably won't.
Thank you again for your hard work, - The DFer
JWR Replies: I concur that "Eleventh Hour" G.O.O.D. is a bad idea. Even if you have 90% of your gear pre-positioned at your retreat, there is the prospect of never making it there safely. (Or, arriving days or weeks late, on foot, only to find your retreat occupied by armed squatters that are gleefully eating from your carefully planned deep larder.) As I illustrated in my novel "Patriots: Surviving the Coming Collapse", being forced to abandon a vehicle and traveling on foot is a dicey proposition, at best. I strongly recommend that readers live at their retreats years round--even if it means giving up a high-paying big city job.
You mentioned: "One might guess that the chance of failure is an exponential function of the distance to the retreat." I would qualify that by saying: "...the distance that you need to traverse in a high population density region to get to the retreat". It is best if one can get away from urban regions fairly quickly and then take secondary or tertiary back roads. For those that are forced by circumstances or family obligations to live a long distance from their intended retreat, I recommend doing some detailed map studies, and then some test drives with a GPS receiver in hand, to establish five or more G.O.O.D. routes--some quite circuitous--to stay away from high population regions and expected refugee lines of drift. Needless to say, always, always, have enough fuel on hand, to make the drive from your home to your retreat without buying any fuel. Depending on the fire code in your town, that might necessitate caching some fuel along your route. (Ideally, with relatives or friends.) Along with that comes the further complication of systematically rotating that cached fuel.)
If and when "The Day" comes, do not hesitate! You need to get out of town well ahead of The Golden Horde, while roads are still passable. It is better to be ultra-cautious and run the risk of burning up some of your hard-earned vacation hours in the event of a few false alarms, than to be complacent and thereby end up stuck in traffic, staring at the tail lights and back bumpers of the enormous horde that left town ahead of you. (Just ask the folks that tried leaving the Gulf Coast cities just before Hurricane Katrina arrived. It was a monumental traffic jam.)