Ohio Rev. Code § 5537.20
The exercise of the powers granted by this chapter is in all respects for the benefit of the people of the state, for the increase of their commerce and prosperity, and for the improvement of their health and living conditions, and as the construction, operation, and maintenance of the Ohio turnpike system by the Ohio turnpike and infrastructure commission constitute the performance of essential governmental functions, the commission, except as provided in division (D) of section 5537.05 of the Revised Code, shall not be required to pay any state or local taxes or assessments upon any turnpike project or infrastructure project funded by it, or upon revenues or any property acquired or used by the commission under this chapter, or upon the income therefrom. The bonds issued under this chapter, their transfer, and the income therefrom, including any profit made on the sale thereof, shall at all times be free from taxation within the state.
R.C. § 5537.20