California Code, Streets and Highways Code - SHC § 8321

(a) Ten or more freeholders may petition the board of supervisors to vacate a street or highway under this chapter.  At least two of the petitioners shall be residents of the road district in which some part of the street or highway proposed to be vacated is situated and shall be taxable therein for street or highway purposes.

(b) Five or more freeholders may petition the board of supervisors to vacate a public service easement under this chapter.  At least one of the petitioners shall be a resident of the township in which the public service easement proposed to be vacated is situated.

(c) The residence address of each petitioner shall be set forth in the petition.

(d) The board of supervisors may require the payment of a fee for filing a petition to defray the expenses of investigations, mailings, publications, and postings under this chapter.  

(e) Upon the filing of a petition and the making of the deposit, if any, required under this section, the board of supervisors, by order, shall fix the date, hour, and place of the hearing on the petition.  At least two weeks before the day set for the hearing, the clerk of the board shall mail a notice of the date, hour, and place of the hearing to each of the petitioners at the address set forth in the petition.

(f) Nothing in this section shall affect the right of a legislative body to initiate a proceeding under this chapter upon its own initiative, or upon petition or request of an interested person, or prevent the board of supervisors from vacating a street, highway, or public service easement without charging costs if the board determines it is in the public interest to do so.