Cal. Sts. & Hy. Code § 970.5
Whenever the board of supervisors or a county officer designated by the board to be in charge of naming county highways finds that a name should be adopted and applied to any county highway, or that the existing name of any county highway should be changed, the board or the designated county officer shall hold a public hearing on the proposed name for, or the change of name of, such highway. Notice of such hearing shall be given by posting notice in at least three public places along the street or streets proposed to be affected, such posting to be complete at least 10 days before the day set for the hearing. At the time set for the hearing or at any time to which the hearing may be continued the board or the designated county officer shall hear and consider proposals to adopt a name for, or change the name of, the highway mentioned in the notice and objections to such proposals. At or after the conclusion of the hearing the board or the designated county officer may adopt a name for, or change the name of, such highway, and upon the adoption or change thereof shall make an order and file said order with the board of supervisors officially designating the name for such highway. Thereafter such highway shall be known by the name so designated.
Ca. Sts. and High. Code § 970.5