California Code, Vehicle Code - VEH § 2400.7

(a) The commissioner may enforce all laws regulating the operation of vehicles and on, and the use of, any portion of any expressway in the County of Santa Clara, if requested by a city or the county with respect to the portion of the highway within that city or county and if a contract is entered into between the state and that city or the county or any combination thereof.

(b) The contract shall require affected cities or the County of Santa Clara, or both, as the case may be, to pay to the commissioner, for deposit in the Motor Vehicle Account in the State Transportation Fund, an amount that is equal to the costs incurred by the department for services provided under the contract.