Cal. Gov't Code § 65302.02
(a) A county or city that is located in a warehouse concentration region, as defined in Section 65098, shall update its circulation element, as required by subdivision (b) of Section 65302, to do all of the following on or before January 1, 2026:
(2) Maximize the use of interstate or state divided highways as preferred routes for truck routes. The county or city shall also maximize use of arterial roads, major thoroughfares, and local roads that predominantly serve commercial, agricultural, or industrial uses when state or interstate highways are not utilized. Truck routes shall comply with the following:
(j)
(1) An action may be brought by the Attorney General against a jurisdiction that is in violation of this section. A city, county, or city and county found by a court to be in violation of this section shall be subject to any of the following: