Our school has short-distance evacuation drills (just like a fire drill, but farther from the school), long-distance evacuation drills (we go to the highschool), they probably do have a drill for "pile into the loving buses, both schools are in trouble", but we do not do them, they also have fire drills, and lockdown drills.
None of the kids take these seriously, which is scary.
Also I just recently realized that the best way to do a school shooting is to pull the fire alarms and shoot all the kids when they walk out. :o