I think this is a good exercise, on several levels. The physical preparedness (fitness, equipment, clothing) is a good thing to test on a regular basis.

I would also recommend looking at trying this with an eye to your routes. You have your normal and probably most direct one, that is most likely. What resources are along that route? What potential safe areas? What potential threats? Do this for two or three more routes as well. Maybe one that stays in a populated area, another that avoids population (if possible). You could also vary transportation methods (vehicle, bicycle, foot, boat if applicable). Note the emergency services along the routes, water sources, areas that provide protection (depending on what the emergency is likely to be). It will increase your situational and area awareness if nothing else.