halacha - Mandatory evacuation on Shabbat: what can and can't you do?

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):

1. 
   

   Should (may? must?) you use a vehicle if it will get you out more quickly, or do you leave on foot?

   
   


2. 
   
   

   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.)

   
   


3. 
   

   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.

Answer

I have a hard time imagining a situation in which you're being forced to evacuate but there isn't some recognizable threat to life.

1. As A.L. said, in the case of pikuach nefesh, you are clearly allowed to do anything to save yourself or someone else, even travelling outside the techum shabbos. If they is something that would be a pikuach nefesh, but there is a safek as to whether there is actually a person in danger, such as a collapsed building that may be empty or the person may already be dead, you are still allowed to do anything involved with potentially saving that life until it is definite whether there is or isn't a person in danger. I believe the gemara discusses a case of an advancing army threatening a city, but never actually attacking. See Shemirat Shabbos Kehilchatah chapter 32 for an in depth treatment of this. Too many mekoros to post here. He even says that even if you fail to save a life or it was rendered unhelpful (e.g.: the person died, the sakanah wasn't as threatening as thought, etc.) you have still performed a mitzvah and you still retain the reward for keeping yom tov (and, presumably shabbos, but he only mentions yom tov).


2. 
   

   A natural disaster like a wildfire would fall under the same category as the gemara mentions, and you can do everything that it discusses vis a vis saving tefillin, food, clothes, etc. As long as we aren't talking about an actual fire or other widespread property damage (see: New Orleans), then the only objects you would be able to take with you would be , hypothetically, what you're wearing. There is no dispensation for transporting objects when total loss is not involved - if your house will survive the storm, so will most everything in it. That being said, there are specific methods for carrying past the techum on foot mentioned in the gemara itself - a carrying line where each person just hands off to the next so no one moves 4 amos means no one is technically violating (carrying is split so no one engaging in the full issur - two people holding a single shirt while walking in public are patur).

   
   

   2 (cont). Additionally, if you don't have to walk through a karmelis to get to your vehicle and an evacuation is ordered where you can drive, you might be able to freely move any non-muktzeh items to your car before driving, assuming you're not creating additional violations by turning on lights by opening the door (you could leave the door open while you load to circumvent this). Your car carrying the load is equivalent to a laden donkey travelling on shabbos, and the gemara explicitly discusses a person putting his wallet on to the donkey before shabbos while in public and leading the donkey into his courtyard before loosening the saddlebags to drop on the floor. Again, this is in a case where travel by care would be permitted - pikuach nefesh - so the techum here isn't an issue. However, Shmiras Shabbos 40:64 (and several footnotes) would seem to imply the opposite - that increasing the burning of gas through additional load in the vehicle is forbidden. Interestingly, this reasoning would not apply to an electric car (and possibly a hybrid with a gas generator and electric motors) where no havarah is being performed directly.

   
   


3. 
   

   Regarding phoning the rabbi, it isn't entirely clear whether it classifies as a full de'oraysa or a de'rabannan, but would the rabbi even know to answer the phone? With only the potential of them answering (because, let's face it, the rav has also been ordered to evacuate) the value of calling is doubtful. The Shemiras Shabbos Kehilchatah (chapter 40:1) states that anyone delaying to ask a question for even a suspected sakanah is considered a murderer. If the situation is so dire that you cannot spend time walking to the rabbi, then it is dire enough that any accidental increase in violations is acceptable to save lives. See the cases in the Shmiras Shabbos mentioned earlier.(32:7, 40:1, 40:62). The language makes clear that you cannot deliberately increase violations of shabbos, but accidental violations and one's performed in better judgement that turned out to be unnecessary shouldn't burden your consciousness.

   
   

Please provide an example situation of an evacuation where you can't spend time to consult a rav but there isn't pikuach nefesh.