(a) This section applies only to an authority confirmed before July 1, 1985, in which the principal municipality has a population of less than 1.3 million.
(b) An authority may not issue short-term debt under Section 451.362 or bonds secured by the revenue of the authority to finance any portion of the purchase, acquisition, construction, operation, or maintenance of a fixed rail transit system unless the system is approved at a referendum under Section 451.071.
(c) If a referendum is approved under Section 451.071, the term for which short-term debt may be issued under Section 451.362 is increased to five years if the purpose of the debt is the purchase, acquisition, construction, operation, or maintenance of the fixed rail transit system approved at the referendum.