California Code, Health and Safety Code - HSC § 40447.5

(a) Require operators of public and commercial fleet vehicles, consisting of 15 or more vehicles under a single owner or lessee and operating substantially in the south coast district, when adding vehicles to or replacing vehicles in an existing fleet or purchasing vehicles to form a new fleet, to purchase vehicles which are capable of operating on methanol or other equivalently clean burning alternative fuel and to require that these vehicles be operated, to the maximum extent feasible, on the alternative fuel when operating in the south coast district. Notwithstanding Section 39021, as used in this subdivision, the term “commercial fleet vehicles” is not limited to vehicles that are operated for hire, compensation, or profit. No regulation adopted pursuant to this paragraph shall apply to emergency vehicles operated by local law enforcement agencies, fire departments, or to paramedic and rescue vehicles until the south coast district board finds and determines that the alternative fuel is available at sufficient locations so that the emergency response capabilities of those vehicles is not impaired.

(b) Encourage and facilitate ridesharing for commuter trips into, out of, and within the south coast district.

(c) Prohibit or restrict the operation of heavy-duty trucks during hours of heaviest commuter traffic on freeways and other high traffic volume highways. In adopting regulations pursuant to this paragraph, the south coast district shall consult with the Department of Transportation and the Department of the California Highway Patrol and the transportation commission of each county in the south coast district. No regulation adopted pursuant to this paragraph shall, however, prohibit or restrict the operation of any heavy-duty truck engaged in hauling solid or hazardous waste or a toxic substance if that truck is required to be operated at certain times of day pursuant to an ordinance adopted for the protection of public health or safety by a city or county or any heavy-duty truck required to be operated at certain times of the day pursuant Section 25633 of the Business and Professions Code.