Michigan Compiled Laws, Chapter 257. Motor Vehicles § 257.644

Sec. 644. (1) When a highway has been divided into 2 roadways by leaving an intervening space or by a physical barrier or clearly indicated dividing section constructed to impede vehicular traffic, a vehicle shall be driven only upon the right-hand roadway and a vehicle shall not park or be driven over, across, or within the dividing space, barrier, or section, except through an opening in the physical barrier, dividing section, or space or at a crossover or intersection established by public authority. Crossovers on limited access highways shall not be used except by vehicles described in section 603,  1 road service vehicles while going to or returning from servicing a disabled vehicle, and as otherwise permitted by authorized signs. “Road service vehicles” means vehicles clearly marked and readily recognizable as a vehicle used to assist disabled vehicles.

(2) A person who violates this section is responsible for a civil infraction.