Authorizes taxes approved by regional transit authority voters to be nullified within the complete boundaries of a county within an authority if a proposition to nullify the taxes is approved by voters.

Requires the county auditor, if a petition to nullify is filed with the county auditor, to canvass the signatures and certify their sufficiency to the governing body within two weeks.

Prohibits the nullified authority taxes from being imposed within the boundaries of the affected county.