Our freeway system is the result of President Eisenhower wanting a fast transportation system for military movement inspired by the Autobahn. California has seen the system suffering localised damage to the Bay Bridge in San Francisco and sections here in the greater L.A. area. Ironically, we lost motorcycle officers in the Northridge and older Saugus-Newhall tremors on collapsed sections. My past experience with 'quakes, fires and mudslides is that localised areas can be hit hard, but the nature of our urban infrastructure ( fancy name for sprawl) usually leaves ajacent areas relatively unaffected. After Northridge people initially panicked over water. But the trucks with those pretty Arrowhead bottles kept rolling in. Merchants merely fell back on pre computer and in some instances telephone communications to keep merchandise flowing. There was the usual percentage of price gauging, looting and drivers that made our allready aggressive road environment look like a Mad Max outtake. But most people were actually quite decent. If you are in a semi rural situation a good radio is essential, perhaps even a police type scanner or a dedicated unit that receives weather and and other civil broadcasts. I would get to know the CHP etc. at the nearest stations. If somebody knows you live somewhere your part of their consciousness and you can glean future information; which roads are safer for evacuations, local dedicated evac centers etc. I've rolled into closed emergency zones to evacuate horses usually closed even to residents. A known reputation and a case of bottled water go a long way.