&sq=&lang=&file=File:M-15.svg) M-15 | ||||
|---|---|---|---|---|
 M-15 highlighted in red | ||||
| Route information | ||||
| Maintained by MDOT | ||||
| Length | 73.664 mi[1] (118.551 km) | |||
| Existed | c. 1927[2]–present | |||
| Tourist routes |  Pathway to Family Fun Recreational Heritage Route | |||
| Major junctions | ||||
| South end |  US 24 near Clarkston | |||
| North end |  M-25 in Bay City | |||
| Location | ||||
| Country | United States | |||
| State | Michigan | |||
| Counties | Oakland, Genesee, Tuscola, Saginaw, Bay | |||
| Highway system | ||||
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M-15 is a north–south state trunkline highway in the US state of Michigan. The southern terminus is a junction with US Highway 24 (US 24) just south of Clarkston on the northwestern edge of the Detroit metropolitan area. The trunkline is a recreational route running north and northwest to the Tri-Cities area. The northern terminus is the junction with M-25 on the east side of Bay City. The total length is about 73+2⁄3 miles (118.6 km) between the two regions.
The original M-15 designation was used in the northern half of the state in 1919. This designation was wholly replaced by the US 41 on November 11, 1926. This previous designation contained the section of highway in Marquette County that is home to the first painted highway centerline in the nation. Another section in western Marquette County included the first bridge built by the state of Michigan. Within the next year after M-15 was replaced by US 41, the designation was reused for a new highway routing along the current highway. This current highway was extended northerly to eventually end at Interstate 75 (I-75) in Bay City, before it was scaled back slightly to end in southeast Bay City. A proposed, but unbuilt, extension around the west side of Metro Detroit later became part of the I-275 corridor.
This highway is now a part of the Pure Michigan Byway System, but none of it is located on the National Highway System. A section of the two-lane highway has the local moniker, "Death Alley", where the local sheriff says the highway is poorly designed. The stretch of highway in Genesee County has been the location of 14 traffic fatalities between 2004 and 2009 as reported by The Flint Journal, including that of a 14-year-old local girl.