US Route 12 in Michigan runs from the southwestern corner of the state, east-northeasterly to Detroit. The course of US Route 12 in the current day is different from US Route 12's original course in Michigan; the original routing of US Route 12 through the state is the corridor currently traversed by Interstate 94. As the Interstate took the stage, the surface route of US Route 12 became largely unnecessary, so US Route 12 was rerouted onto a corridor known as US Route 112. The route formerly known as US Route 112 is the Michigan portion of US Route 12 as we know it today. US Route 12 enters Michigan crossing the state line out of Indiana, right along the shores of Lake Michigan, near New Buffalo. The eastern extent of US Route 12 in Michigan is the corner of Michigan Avenue and Griswold Street in downtown Detroit. Michigan Avenue is the street in Detroit that carries US Route 12. Along its journey from New Buffalo to Detroit, US Route 12 serves a lot of different towns in southern Michigan, including Niles, Coldwater, Ypsilanti, and Dearborn.
My photo of US Route 12 in Michigan is this bright, clean shot of this eastbound reassurance marker near New Buffalo, in the southwestern corner of the Lower Peninsula. East-facing drivers will see this sign as they leave the interchange with Interstate 94 that occurs on the east side of New Buffalo. This photo was taken in early August 2022, coming home from Alpena (on a trip that also involved locales in the Upper Peninsula).