California Motor Vehicle Code 21663
Driving on Sidewalk
Driving on the sidewalks is both illegal and dangerous. Unless you are crossing a sidewalk when entering a parking lot, or leaving your driveway, you should never drive your car on the sidewalk. Sidewalks are for pedestrian use only.
There are a limited number of exceptions that allow big trucks on the sidewalks. Sometimes, local authorities give express permission to certain companies allowing their vehicles to drive and park on the sidewalks, such as the media, emergency vehicles, and utility work-trucks. This is allowed for convenience and worker safety.
Express permission is not the same as implied or assumed. If you have express permission to be on a sidewalk, some local authority has spoken directly to you and given you permission. If you are unsure if you have express permission, then you probably don't have it.
Implied permission is when you see others using the sidewalks and therefore assume that everyone is allowed to drive on the sidewalk. This is not a good assumption and could get you into trouble. If you have not personally been granted permission to drive on the sidewalks, then stay off them.
If you are caught driving on the sidewalks without permission you will be ticketed and face large fines. Stay safe while driving your car or truck, and stay off the sidewalks.