California Military And Veterans Code Section 396
The commanding officer of any portion of the militia parading
or performing any military duty in any street or highway may require
persons in such street or highway to yield the right of way to such
militia, except that the carriage of the United States mail, the
legitimate functions of the police, and the progress and operations
of hospital ambulances, fire engines, and fire departments and
apparatus shall not be interfered with thereby.
Any person who hinders, delays, or obstructs any portion of the
militia parading or performing any military duty, or who attempts so
to do, is guilty of a misdemeanor.