We have been evacuated 6 times in the past 10 years due to fires. Living in the foothills means two roads to get in or out of our area. The fire department usually closes one of the two roads because of the fires or to use it only for emergency vehicles. We have spent hours trying to merge into traffic just to get out of our neighborhood. Most people don't think of this until the need is there, plus you will probably be moving a number of vehicles and family members are separated as they are all driving or in different vehicles.
The time our dam was failing and they evacuated our town for a week was a different experience. Since we live just above the dam we were told to shelter in place. After a couple of days I drove down our road to get supplies. I was stopped by our Highway Patrol. They said I could leave, but they would not let me return until the evacuation notice was lifted. That didn't happen for another 3 days. We were glad we had enough supplies, but power had been shut off. We had enough gas to keep the generator running the whole time.
These were things we really hadn't thought about until we were in the middle of them. Plan now before your options are taken away from you.