Mich. Comp. Laws § 380.1276
The board of a school district or a local act school district may acquire by purchase or lease or may construct pedestrian overpasses for the safe conduct of pupils enroute to and from school. The costs may be paid by the school district and by the highway authority having jurisdiction of the public highway in amounts agreed upon by the board and the highway authority. The board may pay its share out of the general funds of the school district, or may purchase the overpasses on title retaining contracts. The contracts shall not be entered into or issued for more than 10 years. A pedestrian overpass shall not be constructed over a public highway without the prior approval of the highway authorities having jurisdiction over the highway.
MCL 380.1276