Your biggest SHTF scenarios in California are Earthquakes, Nuclear Powerplant meltdown, Forest Fires, Storm systems (think of a really bad San Andres winds), and rioting/gang violence.
Having lived in California for over a decade I have experienced all of the above with exception of a meltdown. I now live in NY and not NY,NY (Manhattan, Brooklyn, Bronx)
Getting to the airport in a non SHTF (I lived in Sylmar, Ca) took hours for a 31 mile drive on a 5 lane highway. You will be competing with everyone to fly out.
You location makes things tricky. Bugging out is when there is no way you can safely remain at your home. A powerplant meltdown or a forest fire is a no brainer to bug out. You typically have 1-2 hours when you have advanced warning to bug out before you lose your window of opportunity and then that stop and go traffic is gonna happen ( less for a meltdown as that is when its time to start abandoning your possessions as time is literally ticking away).
Earthquakes on the other hand, unless there is enough of an advanced warning (and often there is not) will knock down power lines, trees, bridges, overpasses, highways. Depending where the quake originates, leaving by sea could be out of the question due to tsunamis. Trying to bug out with a full tank of gas in stop and go traffic or extremely slow driving trying to find roads that are still intact could end up stranding you in your vehicle that ran out of gas.
Personally I would move out of California if I were you, as I did just that.
I remember one earthquake streets were blocked by fallen trees and electric lines, roads had buckled, the overpass leading to the highway broke in half, making bugging out impossible for a lot of residents. My step father was a retired Navy officer and a prepper and had a stock pile of food and water which saved us as stores )those were open) only accepted cash as credit card machines were down and one couldn't go to the bank to withdraw money.
My best advice to you is to make numerous escape routes planned in advanced marked by different highlighter colors on your map. Have a GPS with you either GPS device or phone app to assist you when your route section is unpassable. Stock pile food and water incase you are unable to get out, and especially find a way to protect your family and home. This means coating your windows with a film so it doesn't shatter when hit with a hammer, installing security bars on your windows, getting a reinforced metal door that has a metal frame that the door attaches to, set up your vehicle to be a Bug Out vehicle with food, water & gear. ( i would also say have a bike rack with everyone's bikes case u run out of gas)
If you have friends in different cities nearby ask them if something happens can your family stay there for an additional bug out location.
Escaping into the wild should only be done if you are a highly skilled bushman/outdoorsman with hunting, gathering & building skills, and even then this would be the last resort when all other options have been exhausted. If you do not have the skills listed above, Do Not attempt escaping into the wilderness, as then you will end up as a statistic.
Invest in some sleeping bags, LED lanterns, solar power generator, rechargeable batteries n charger, walkie talkies, CB radio, dual fuel stoves and dual fuel lanterns (Coleman 533 single burner stove or the Coleman Guide series dual fuel two burner stoves that looks like a briefcase, and dual fuel two mantle lantern) so you can siphon from your vehicle if stranded to fuel these devices. Get a am/fm world solar crank radio with weather alert, led headlamp & flashlights.
Some additional items phone power bank, solar panel, power inverter (12v to 110v), a few UPS battery backup surge protectors (when the power goes out these can charge multiple devices up to an hour and a half depending on model to charge laptops, tablets, phones, power banks, or to run a tv or radio to hear news updates) HAM Radio (by this point it even if u don't have the ham license it is better to get a hefty fine then to be in the dark without communication- realize that cell phone service is likely to be interrupted or inaccessible due to power outages or mass hysteria with entire state trying to call out . This was the case during 9/11 in NY)
Fingers crossed that no SHTF any time soon for ya there mate.
Personal motto: I rather to have and not need then need but not have the gear for my survival.