 I-675 splits off to run westward into downtown, and I-75 curves around to the northwest to cross the Saginaw River on the Zilwaukee Bridge in the suburb of Zilwaukee.North of the river, I-675 reconnects to I-75, which continues northward into Bay County.The freeway passes to the west of Bay City, encountering the eastern end of the US 10 freeway.