Michigan Compiled Laws, Chapter 257. Motor Vehicles § 257.1810a

Sec. 10a. (1) A school may contract with a licensed motor carrier of passengers for a motor bus to be used for occasional transportation of pupils to or from school-related events.A school shall not directly operate a motor bus for the use of pupil transportation to and from school or school-related events. A motor carrier certified by the state transportation department shall not use a motor bus to transport pupils to and from school.

(2) Before the effective date of the amendatory act that amended this section, 1the department of education may authorize the use of a motor bus for the regular route transportation of pupils to or from school or home. The authorization shall be in writing and shall include conditions or restrictions that are necessary to safeguard the health, safety, and welfare of the pupils.Any authorization that is entered into before the effective date of the amendatory act that amended this subsection  1 shall remain in effect for the time it is authorized.

(3) A motor bus built to school bus specifications that complies with the applicable federal motor vehicle safety standards shall comply with the requirements of this act.