After reading this thread, and several others recently, I have a glaring concern that i'm afraid a lot of you haven't considered. At least not vocally on these threads...
My question is this: If you plan to drive to your bug out location, have you stopped to consider the probability (not possibility) that people between your point of origin and your bug out location, will not want you to come where they are? Even if you're just "passing through".
Think defensively for a second... if you live on a country road or secluded area and you were bugging in, wouldn't you obstruct access to your area in any way possible? Even to people "passing through". Deter them before they get there, or make it as hard as possible to get there in the first place, so to speak? Things as simple as glass, nails, and screws in the road will lead to cars blocking it shortly there after.... rocks, downed trees, useless power-poles, concrete medians turned sideways, etc will be plentiful and just having a "4-wheel drive" doesn't do enough.
The way I see it, roads will be impassable one way or another and people are going to be on the defensive when you're intruding on their territory.
One example, and I can just see it now... i70 is blocked by who knows what, in Genessee, Floyd Hill, or at least the tunnel. ha.
You'll be best served to bug in as long as possible.