California Code, Public Utilities Code - PUC § 99234.5

(a) The Counties of San Bernardino, Riverside, and Los Angeles may enter into a joint powers agreement pursuant to Article 1 (commencing with Section 6500), Chapter 5, Division 7, Title 1 of the Government Code, and the joint powers entity created pursuant to such agreement shall in accordance with Section 403 of the Rail Passenger Service Act of 1970 (45 U.S.C. 563), request the National Railroad Passenger Corporation to institute up to two additional trains a day in each direction between Los Angeles and San Bernardino to supplement the present level of service. The joint powers entity may request institution of more than two additional trains a day in each direction between Los Angeles and San Bernardino. Contributions shall be made from the fund of each of the three counties, as agreed by them, to the joint powers entity, as may be required by the National Railroad Passenger Corporation to meet a reasonable portion of any losses associated with such service. The joint powers entity may request that the additional trains shall be operated, to the extent practicable, during periods of peak traffic.

(b) If the funds available under this chapter are insufficient for purposes of subdivision (a), the board of supervisors of any one of the three counties may make contributions to the joint powers entity from any funds available to it.