as bws48 commented...you are in an OODA loop with your decision making process, and those of us not living in the earthquake region can only offer suggestions not made from actual experiences...I'll offer some generic comments..

my GHB(hydration pack built in) is in the car...and even at my age can probably make 30 miles a day provided I can access water I can purify (Sawyer filter bottle)...food for two days @ 2 meals a day plus snack....additionally in the car...16 pack of water dedicated, plus partial case of water and GatorAde I use for shooting competitions...Swiss Ranger stove and Sterno to cook with...fence pliers/machete if I need to make a short cut through a chain link fence

tarp and cordage, poncho and mosquito netting in GHB... for sun shade if I wait for help and camp in car

handgun, extra mags, Israeli dressing and QuickClot in a non threatening shoulder bag

pretty extensive trauma FAK

12v charger for EDC'd cell phone... connected it may give you extra charge to access to marginal towers if local ones damaged

my GPS is a Garmin nuvi 500 and has topo maps of the US...also an old copy of an Rand McNally Road Atlas

I drive about 150 roundtrip miles a week on the interstate, so have a "peaked" CB with a 12v cigarette power cord...although semi permanent mounted with velcro and plastic cable ties to the underside of the ash tray...could easily be stowed in a gym bag..I purchased a good magnetic mount antenna and adjusted the standing wave ratio to a location on the rear roof of my Explorer...even with the antenna tied down to enter my garage door, get a couple of miles range...I get good intel from truckers as to traffic slowdowns and open alternative routes... small portable AM/FM battery portable in GHB

for vehicle support...good pair of jumper cables, full size spare, tire plug kit, assorted hand tools, and hand air pump

I have no immediate need to make it home...I'm single, no pets to feed, and not a care giver...I would like to think that I could if the circumstances required it...

good luck