High Quality Content by WIKIPEDIA articles! M-84 is a state trunkline highway in the Lower Peninsula of the US state of Michigan. The highway starts on the west side of Saginaw at an intersection with M-58 and runs north through residential and commercial areas. There are two colleges or universities near the trunkline as it connects Saginaw with Bay City, providing an alternate to the freeway that carries Interstate 75/US Highway 23 (I-75/US 23). The northern terminus is at a pair of intersections with M-25 on the east side of the Saginaw River in Bay City.