Mich. Comp. Laws § 247.291b

Sec. 1b. As used in this act: (a) "Crashworthy" means that term as defined in the Michigan manual on uniform traffic control devices. (b) "Freeway" means that term as defined in section 18a of the Michigan vehicle code, 1949 PA 300, MCL 257.18a. (c) "Highway" includes roads and streets. (d) "Michigan manual on uniform traffic control devices" means the manual on uniform traffic control devices adopted under section 608 of the Michigan vehicle code, 1949 PA 300, MCL 257.608. (e) "Suitable barrier" means a barrier that conforms to the Michigan manual on uniform traffic control devices.