M-17 is a 6.390-mile-long (10.284 km) state trunkline highway in the U.S. state of Michigan, connecting the cities of Ypsilanti and Ann Arbor in Washtenaw County. It was once part of a highway that spanned the southern Lower Peninsula of Michigan before the creation of the U.S. Highway System in 1926. The designation once extended into downtown Detroit, but the eastern terminus was progressively scaled back in the late 1960s to the current location in Ypsilanti. The changes made to the highways in Washtenaw County spawned Business M-17, a business loop for 11 years between 1945 and 1956.
Cross Street, one-way, facing west
Michigan State Trunkline Highway System
The State Trunkline Highway System consists of all the state highways in Michigan, including those designated as Interstate, United States Numbered, or State Trunkline highways. In their abbreviated format, these classifications are applied to highway numbers with an I-, US, or M- prefix, respectively. The system is maintained by the Michigan Department of Transportation (MDOT) and comprises 9,669 miles (15,561 km) of trunklines in all 83 counties of the state on both the Upper and Lower peninsulas, which are linked by the Mackinac Bridge. Components of the system range in scale from 10-lane urban freeways with local-express lanes to two-lane rural undivided highways to a non-motorized highway on Mackinac Island where cars are forbidden. The longest highway is nearly 400 miles (640 km) long, while the shortest is about three-quarters of a mile. Some roads are unsigned highways, lacking signage to indicate their maintenance by MDOT; these may be remnants of highways that are still under state control whose designations were decommissioned or roadway segments left over from realignment projects.
Welcome sign along US 8
M-553 approaching Glass' Curve south of Marquette
M-121 in Jenison
Grand River Avenue, once a part of M-16 and later US 16, was originally an Indian trail converted as a plank road before becoming a state highway.