Mich. Comp. Laws § 259.482b

Sec. 2b. (1) Based upon the most precise approach available or planned for either end of a runway, the width of the primary surface is 1 of the following: (a) For a utility runway that permits only a visual approach 250 feet (b) For a utility runway that permits a nonprecision instrument approach 500 feet (c) For other than a utility runway that permits only a visual approach 500 feet (d) For other than a utility runway that permits a nonprecision instrument approach and for which the FAA has established a visibility minimum that is greater than 3/4 of a statute mile 500 feet (e) For other than a utility runway that permits a nonprecision instrument approach and for which the FAA has established a visibility minimum that is as low as 3/4 of a statute mile or less 1,000 feet (f) For a runway that permits a precision instrument approach 1,000 feet (2) Based upon the type of runway surface, the length of the primary surface is 1 of the following: (a) For a runway with a prepared hard surface or for which there are plans for a prepared hard surface, the length of the runway plus 200 feet beyond each end of the runway. (b) For a runway other than a runway described in subdivision (a), the length of the runway. (3) The elevation of a point on a primary surface is the same as the elevation of the point on the runway's centerline nearest to the point on the primary surface.