California Code, Public Utilities Code - PUC § 90503

Indebtedness which has been incurred for the acquisition, construction, and operation of transit facilities, where the revenue from the transit facilities for three years or more next preceding has been sufficient to pay the interest and principal due on any bonds issued for its construction or acquisition, in addition to the cost of operation and maintenance, shall not be counted and included in ascertaining the limit of indebtedness.