Mich. Comp. Laws § 257.634: Driving on right half of roadway; exceptions; driving on roadway having 2 or more lanes for travel in 1 direction; traveling on freeway having 3 or more lanes for travel in same direction; ordinance regulating same subject matter prohibited; violation as civil infraction.

Sec. 634.

(1) Upon each roadway of sufficient width, the driver of a vehicle shall drive the vehicle upon the right half of the roadway, except as follows:

(a) When overtaking and passing another vehicle proceeding in the same direction under the rules governing that movement.

(b) When the right half of a roadway is closed to traffic while under construction or repair or when an obstruction exists making it necessary to drive to the left of the center of the highway. A driver who is driving on the left half of a roadway under this subdivision shall yield the right-of-way to an oncoming vehicle traveling in the proper direction upon the unobstructed portion of the roadway.

(c) When a vehicle operated by a state agency or a local authority or an agent of a state agency or local authority is engaged in work on the roadway.

(d) Upon a roadway divided into 3 marked lanes for traffic under the rules applicable on the roadway.

(2) Upon a roadway having 2 or more lanes for travel in 1 direction, the driver of a vehicle shall drive the vehicle in the extreme right-hand lane available for travel except as otherwise provided in this section. However, the driver of a vehicle may drive the vehicle in any lane lawfully available to traffic moving in the same direction of travel when the lanes are occupied by a streetcar or vehicles moving in substantially continuous lanes of traffic and in any left-hand lane lawfully available to traffic moving in the same direction of travel for a reasonable distance before making a left turn or to avoid blocking, delaying, or otherwise interfering with the movement of a streetcar on a streetcar track.

(3) This section must not be construed to prohibit a vehicle traveling in the appropriate direction from traveling in any lane of a freeway having 3 or more lanes for travel in the same direction. However, a city, village, township, or county may not enact an ordinance that regulates the same subject matter as any provision of this subsection. The driver of a truck with a gross weight of more than 10,000 pounds, a truck tractor, or a combination of a vehicle and trailer or semitrailer shall drive the vehicle or combination of vehicles only in either of the 2 lanes farthest to the right, except for a reasonable distance when making a left turn or where a special hazard exists that requires the use of an alternative lane for safety reasons.

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