Indiana Code Title 36. Local Government § 36-9-4-46

Sec. 46. (a) The board of directors of a public transportation corporation that issues bonds under this chapter shall levy a special tax each year upon all the property within the taxing district of the corporation.  The tax shall be levied in such a manner as to meet and pay the principal of the bonds as they mature, together with all accruing interest.

(b) The county treasurer shall collect the tax in the same manner as other taxes are collected.  As the treasurer collects the tax, the treasurer shall remit it to the controller of the public transportation corporation.

(c) In determining the amount of the levy, the board of directors shall consider any surplus of accumulated revenue derived from the operation of the urban mass transportation system, above the sum considered necessary to be applied upon or reserved for the payment of the operating and capital expenditures of the system, including expenditures for the replacement of and additions to the property of the system and reserves established for the depreciation of the property of the system.  If the board finds that this surplus is sufficient, it may apply all or part of the surplus to the payment of the principal of the bonds, together with the interest on them.