California Code, Public Utilities Code - PUC § 99270.1

If an operator serves urbanized and nonurbanized areas in the area of jurisdiction of a transportation planning agency, the transportation planning agency shall adopt rules and regulations to determine what portion of the public transportation services of the operator serves urbanized areas and what portion serves nonurbanized areas to determine its required ratio of fare revenues to operating cost, as defined by subdivision (a) of Section 99247, or its required ratio of the sum of fare revenues and local support to operating cost, or both.

The transportation planning agency shall submit the rules and regulations to the department for approval.