I was leaving on a car trip a few years back, and unbeknownst to me, about 20miles up the road, a huge thunderstorm had brought down some trees and power lines, blocking one part of the northbound highway, during early rush hour. We got stuck for 3 hours trying to get past it. No matter which side road, turn, whatever we took, it was jammed. We waited for an hour on one small side road only to get sent back because a line was down at an intersection. This wasn’t a major natural disaster, things went back to normal in a couple hours. But it really drove home to me how pointless it would be relying on escaping/evacuating from a real disaster if you didn’t get out early. I don’t say this to suggest that people shouldn’t follow evacuation orders, they absolutely should; an evacuation order is early warning. I’m saying this to suggest that none of us should assume that we’ll just be able to get out in an emergency, particularly in a car. It just doesn’t take that many people on the road to completely seize the system.