I'll throw in some thoughts from here at Los Angeles. By the way - you would think that the majority of people in Southern California would be ready for the Big One. But in actual fact they are not. This problem is also the Number One hazard from a giant earthquake in L.A. The problem is not just the damage to the city, but rather how the civilian population reacts after the earthquake. Los Angeles has few sources of fresh water, and not a lot of good road access (esp. if major freeways are down). So that means that in 2-3 days after a major (widespread) quake, when huge numbers of people starting running out of drinkable water, things could turn pretty ugly.

Setting that issue aside for now, there have been a number of excellent thoughts expressed on this thread:
1. Put some earthquake supplies in your vehicle.
2. Have a good plan to build a makeshift toilet (something that stops contamination getting into ground water).
3. Be prepared to sleep outside for extended periods of time
4. If you've got pets - how are you going to feed them and get them water?
5. The more food storage and water storage you've got - then the less reasons you have for being out on the streets. This reduces your chances of unfriendly encounters a lot.

I'd like to bring up one of the major challenges. Although death is unlikely, debilitating injuries are certainly possible. Open wounds, compound fractures of limbs, skull fractures, burns, etc. These kinds of things can cause a lot of pain. It is reasonable to think that good medical attention may not exist for weeks. And pain medication for severe injuries is not allowed for civilians. So there are real problems related to wound care, prevention of infection, pain experienced over long periods of time, and lack of sleep.

other Pete