"School bus" means every bus meeting the requirements of the Ohio Departments of Education and Highway Safety and designed for carrying more than nine passengers which is owned by a public, private or governmental agency or institution of learning and operated for the transportation of children to or from a school session or a school function, or owned by a private person and operated for compensation for the transportation of children to or from a school session or a school function; provided "school bus" does not include a bus operated by a municipally owned transportation system, a mass transit company operating exclusively within the territorial limits of the Municipality, or within such limits and the territorial limits of municipal corporations immediately contiguous to the Municipality, nor a common passenger carrier certified by the Public Utilities Commission of Ohio unless such bus is devoted exclusively to the transportation of children to and from a school session or a school function.
(ORC 4511.01 (F))