Interstate 94 in Michigan
Interstate 94 (I-94) is a part of the Interstate Highway System that runs from Billings, Montana, to the Lower Peninsula of the US state of Michigan. In Michigan, it is a state trunkline highway that enters the state south of New Buffalo. It runs east through the metropolitan areas of Benton Harbor, Kalamazoo, Battle Creek, Jackson, Ann Arbor, and portions of Metro Detroit, before angling northeasterly to Port Huron, where it terminates on the Blue Water Bridge at the US–Canadian border.
The first segment of what later became I-94 within the state, the Willow Run Expressway, was built near Ypsilanti and Belleville in 1941, with an easterly extension to Detroit in 1945. This expressway was initially numbered M-112. By 1960, the length of I-94 was completed from Detroit to New Buffalo, with subsequent extensions in the 1960s completing most of the rest of the route. The last segment opened to the public in 1972 when Indiana completed their connection across the state line. The routing of I-94 is notable for containing the first full freeway-to-freeway interchange in the United States, connecting to the Lodge Freeway (M-10), and for comprising the first complete border-to-border toll-free freeway in a state in the United States. The highway has one auxiliary route, Interstate 194, serving downtown Battle Creek, and eight business routes.