(a) In this section, “taxing authority” means:
(1) a rapid transit authority created under Chapter 451, Transportation Code;
(2) a regional transportation authority created under Chapter 452, Transportation Code;
(3) a crime control district created under the Crime Control and Prevention District Act (Article 2370c-4, Vernon’s Texas Civil Statutes); or
(4) a corporation created under Chapter 504 or 505.
(b) Except as provided by § 334.0855, if a municipality or county is included within the boundaries of another taxing authority and the adoption or increase of the tax under this subchapter would result in a combined tax rate of more than two percent in any location in the municipality or county, the election to approve or increase the tax under this chapter is to be treated for all purposes as an election to reduce the tax rate of the other taxing authority (except a rapid transit authority created under Chapter 451, Transportation Code) to the highest rate that will not result in a combined tax rate of more than two percent in any location in the municipality or county. If the municipality or county is located within the boundaries of only one taxing authority, and the adoption or increase of the tax under this subchapter will result in a decrease of the tax rate of the taxing authority, the ballot at an election to impose or increase the tax must clearly state that the adoption or increase of the tax will result in a reduction of the tax rate of the taxing authority. If the municipality or county is included within the boundaries of more than one taxing authority, the election to impose or increase the tax under this subchapter must allow the voters to choose which taxing authority’s tax will be reduced.

(b-1) If the voters choose reduction of the tax collected by a rapid transit authority created under Chapter 451, Transportation Code, and imposition of the tax authorized under this section would result in a reduction of the rapid transit authority’s tax rate to the highest rate that will not result in a combined tax rate of more than two percent in any location in the municipality or county, an election must be held pursuant to Subchapter M, Chapter 451, Transportation Code, as applicable for the type of authority involved, on the question of withdrawing the affected municipalities from the authority prior to imposition of the tax authorized in this section. If withdrawal is not authorized, the tax may not be imposed unless authorized pursuant to subsequent election(s). Upon withdrawal of each affected municipality from the authority (if withdrawal is authorized), the obligation to provide service (including service to persons with disabilities) shall be discontinued for that municipality except as required under applicable federal law. In all other respects, the provisions of Subchapter M, Chapter 451, Transportation Code, governing withdrawal procedures and obligations of municipalities upon withdrawal shall apply.
(c) The rate of the tax imposed by the other taxing authority is increased without further action of the board of the authority or the voters of the authority, municipality, or county on the date on which the tax imposed under this subchapter is decreased or expires, but only to the extent that any tax imposed by the authority was reduced under this section when the tax imposed by the municipality or county was adopted or increased.
(d) This section does not permit a taxing authority to impose taxes at differential tax rates within the territory of the authority.