Michigan Compiled Laws, Chapter 257. Motor Vehicles § 257.726c

Sec. 726c. (1) A duly authorized agent of a county road commission when enforcing sections 215, 255, 631(1), 717, 719, 719a, 720, 722, 724, 725, and 726  1 shall wear a shoulder patch that is clearly visible and identifies the branch of government represented.

(2) A duly authorized agent of a county road commission shall not carry a firearm while enforcing sections 215, 255, 631(1), 717, 719, 719a, 720, 722, 724, 725, and 726 unless he or she is licensed or certified as a police officer under the Michigan commission on law enforcement standards act, 1965 PA 203, MCL 28.601 to 28.615.