California Code, Streets and Highways Code - SHC § 1722

The governing body of the city, by resolution, may consent to the establishment of the proposed county highway and may relinquish to the county in whole or in part an existing city street. If the governing body of the city wishes to change the location or relocation of the highway proposed by the board of supervisors, it may adopt a report describing the proposed revisions and file a copy with the board of supervisors. The board shall consider the report and may modify its resolution. If the board modifies its resolution it shall forward a copy of such resolution to the governing body of the city. The city may then adopt a resolution of consent to the modified county resolution.