Still here in Tokyo, with food, water, shelter, communication, electricity and gas. I appreciate the continuity of them all, and have been given great pause to my family's vulnerability to a cessation of any of them. The biggest lesson is the 'black swan event'. People in Japan well know to have a regular earthquake kit, cash on hand, food, fuel, medicines and water in storage, but this level of nuclear incident was not foreseen. In hindsight that seems pretty stupid of all of us here, because Tepco is well known for lies and incompetence, and tsunami are a well known and geologically regular phenomena.
Transportation is the next concern. This has been an ongoing problem in the disaster zone, and to a lesser extent the rest of the country which has some fuel shortage. Here are your solutions.
Even if you can get fuel for your car, you cannot get anywhere in one. On my 12km Tokyo walk home after the quake the outbound roads were jammed with cars, as the sidewalks were with people, but the people on foot could still make 5km/hr, whereas the cars made much less than that. Bicycles did even better, and small motorbikes moved with mixed results, as they cannot get through all the spaces that even a bicycle can. I got home in two and a half hours, whereas my wife's cousin who did a similar distance as a car passenger took six hours. In addition, one of the reasons we have not left Tokyo is that the 80km trip to Narita airport is no longer an option by car, and an ordeal by train, running at 50% of regular service.
If you are alone and able-bodied, the bicycle is your best escape vehicle. My longest day on one is 160km, and there are people who have done far more than that. Were I alone, and were I sufficiently motivated, I could rely on doing 200km in a day, at minimum. I'd need no fuel but whatever food I had in my home. A bicycle is also financially disposable, should you fly out of your escape location.
A motorbike or scooter is the solution if you are not able-bodied, or you are responsible for anyone else (wife and infant child, in my case). Make sure you have a two-seat version. The advantages of a scooter over a motorcycle are quite a few, especially because you will not be able to make it to highway speed anyway, when the roads are crowded: it is financially disposable, you do not need a motorcycle licence to drive one up to 50cc in Japan, one full tank (4l) will take you somewhere less than 500km, and it is field-repairable to a greater extent than a more complicated vehicle.
Of course, you need to do a proper cost/benefit analysis of the risks: sorry for the lack of links, but last I read your injury and fatality rate on a motorcycle or scooter is double what it is in a car, in Japan; I'd guess it is double again, in North America. If you are regularly riding your motorbike in case you may someday have a need to flee, that's a poor bargain. There is also the issue of fuel storage. The best preparation is to always have a full tank, and another tank you can strap to the back for another 500km, as we have seen fuel access is unreliable. The problem with that is any benefit of having the fuel near your domicile may be outweighed by the fire risks. Thousands more died in Kobe than would have had their oil-heaters not fuelled the fire following the quake.