M-3, known for most of its length as Gratiot Avenue, is a north–south state trunkline highway in the Detroit metropolitan area of the US state of Michigan. The trunkline starts in Downtown Detroit and runs through the city in a northeasterly direction along one of Detroit's five major avenues. The highway passes several historic landmarks and through a historic district. It also connects residential neighborhoods on the city's east side with suburbs in Macomb County and downtown.

M-85, also known as Fort Street or Fort Road for its entire length, is a state trunkline highway in the U.S. state of Michigan. The highway serves several Downriver suburbs of Detroit, as well as neighborhoods in the city itself. From its southern terminus at exit 28 on Interstate 75 (I-75) to its second interchange with exit 43 on I-75 in southwest Detroit, M-85 is part of the Lake Erie Circle Tour. In between, it serves mostly residential areas running parallel to a pair of rail lines; the highway carries between 5,000 and 43,000 vehicles per day on average. Once in the city of Detroit, Fort Street runs parallel to I-75 for several miles before they separate near the Ambassador Bridge. The northern end of M-85 is at the intersection with Griswold Street in downtown Detroit, one block away from Campus Martius Park.