There are too many variables. If it was possible to design a perfect method it'd probably never be needed but you can't 'program' human beings to do the specific correct thing every time. That said, I suppose a very hypothetical solution would be to make every seat a 'Bond villain' seat, you know the one where as soon as you sit down heavy metal restraint bands snap into place AND make every seat an ejector seat. That way as soon as 'EVAC' is announced one of the CC flicks a switch and 'woosh' .. off they go...
