Mich. Comp. Laws § 257.30c: "Modified agriculture vehicle" defined.

Sec. 30c.

"Modified agriculture vehicle" means a vehicle that satisfies both of the following conditions:

(a) It has been modified from its original use so that the transport of agricultural commodities is the vehicle's primary purpose.

(b) It is certified by the United States department of transportation and United States environmental protection agency for road use before being modified as described in subdivision (a).