Mich. Comp. Laws § 257.22

Sec. 22. "Intersection" means: (a) The area embraced within the prolongation or connection of the lateral curb lines, or, if none, then the lateral boundary lines of the roadways of 2 highways which join one another at, or approximately at, right angles, or the area within which vehicles traveling upon different highways joining at any other angle may come in conflict. (b) Where a highway includes 2 roadways 30 feet or more apart, then every crossing of each roadway of such divided highway by an intersecting highway shall be regarded as a separate intersection. In the event such intersecting highway also includes 2 roadways 30 feet or more apart, then every crossing of 2 roadways of such highways shall be regarded as a separate intersection.