A major storm hit New England starting this past Friday. While people knew this was coming and precautions were already in place, apparently (according to a news article I read tonight) some areas were declared for mandatory evacuation on Saturday morning. This led me to wonder what one must, may, and must not do in such a situation (assuming no immediate threat to life/health, just a "get out of here" decree):
Should (may? must?) you use a vehicle if it will get you out more quickly, or do you leave on foot?
What may you take with you? Is it the same as what you may take from a burning house on Shabbat, or different? (The talmudic discussion of the burning house seems to be about removing things a short distance, which is not this case. In an evacuation, even if there's a still-intact eiruv you're almost certainly going to go past the boundary.)
If you don't know a matter of halacha you should of course CYLR. When you're in the midst of the situation on Shabbat, is it better to phone your rabbi (guaranteed melacha) in order to minimize further violations, or to use your best judgment and risk more, unintended violations? (Assume you don't have time to walk to your rabbi and back.)
An informative article by R. Kenneth Brander (h/t DoubleAA and Ze'ev Felsen) addresses some halachic issues of severe weather on Shabbat, but doesn't specifically address (non-medical) evacuation issues.