Under California law, lane splitting is permitted by a California motorcyclist, but it must be done in a safe and prudent manner.  Thus, you are allowed to do it on all San Diego County freeways, and throughout the state of California.  It is possible that you could be at fault for a motorcycle vs. car accident if you did not lane split in a safe and prudent manner!  Also, do not forget, some police and jurors have a built in bias against motorcyclists because they are allowed to lane split under California law.  Be careful when you lane split on a motorcycle in California!