Mich. Comp. Laws § 462.229

Sec. 229. (1) Any railroad company operating a railroad in this state may own and operate automobile buses or motor vehicles and trailers for the purpose of transporting persons and property upon the public streets or highways for hire, subject to the provisions of law regulating such transportation upon the public highways; but only after having obtained the appropriate certificate of public convenience and necessity. A railroad company may also own and operate equipment for, and engage in, aerial transportation. (2) A railroad company may purchase and own capital stock and securities of corporations organized for, or engaged in, the business authorized in this act, may operate the properties or any part or parts of such corporations by way of lease or any other agreement, and may enter into working arrangements and agreements with such corporations.