I would say an evacuation is one of the best use cases of cars I can think of. Cars are most likely packed with people and stuff and not just single drivers commuting. Everyone can start at a different point and - even more important - head into a different direction once you left the immediate surroundings of the evacuation zone. And cars are at - least temporarily - indepenent from energy infrastructure. If you have a power outage in an area, many cars will still have sufficient fuel or electricity in board to reach the next working petrol or charging station.