M-37 is a north–south state trunkline highway in the US state of Michigan. The southern terminus is near the border between Kalamazoo and Calhoun counties at exit 92 of Interstate 94 (I-94) southwest of Battle Creek. The northern terminus is at the Mission Point Light on Old Mission Point in Grand Traverse County. In between, the highway connects Battle Creek, Grand Rapids and Traverse City. Motorists will travel through agricultural land, forests, suburbs and large cities along the way. The section of M-37 on the Old Mission Peninsula was designated what is now a Pure Michigan Scenic Byway in 2008.
M-99 is a north–south state trunkline highway in the Lower Peninsula of the US state of Michigan. It runs from the Ohio state border, where it connects to State Route 15 (SR 15), north to Lansing, where it terminates at a junction with Interstate 496 (I-496) and the Capitol Loop. The highway mainly serves local communities along the route as it passes through farm lands in the southern part of the state. One short segment, in Jonesville, is routed concurrently with US Highway 12 (US 12). The segment within Lansing follows Martin Luther King Jr. Boulevard.
M-46 is an east–west state trunkline highway in the US state of Michigan between Muskegon and Port Sanilac, terminating near Lake Michigan and Lake Huron on each end. Except for the north–south segment that corresponds with the US Highway 131 (US 131) freeway between Cedar Springs and Howard City, M-46 is practically a due east–west surface highway. The road runs through rural sections of the Lower Peninsula connecting several freeways including US 31, US 131, US 127 and Interstate 75 (I-75).
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.
M-20 is a state trunkline highway in the US state of Michigan that runs from New Era to Midland. It crosses through rural Lower Peninsula forest land between the two ends. The highway serves the college towns of Big Rapids and Mt. Pleasant, home of the main campuses of Ferris State University and Central Michigan University, both located near the trunkline.
M-120 is a state trunkline highway in the US state of Michigan in the southwest Lower Peninsula. The highway runs northeast from Muskegon to Hesperia. In between, the road passes through suburban Muskegon, forests and farmland. Some 5,900–26,000 vehicles use the highway each day on average as it runs long a series of roads that follow county lines in the area.
M-119 is a 27.548-mile (44.334 km) state trunkline highway entirely within Emmet County in the US state of Michigan. The highway follows the shore of Lake Michigan and the Little Traverse Bay, with its southern terminus at US Highway 31 (US 31) near Bay View, about four miles (6.4 km) east of Petoskey; the northern terminus is at a junction with county roads C-66 and C-77 in Cross Village. North of Harbor Springs, the highway is known as the Tunnel of Trees Scenic Heritage Route. This section of highway lacks a centerline and is known for its scenic beauty. On an average day, between 2,000 and 15,000 vehicles use various parts of the highway.
F-41 is a county-designated highway in the Lower Peninsula of Michigan. It was previously designated as M-171, a former state trunkline highway, until 1960, running from US Highway 23 (US 23) just north of Oscoda, and coming back to US 23 about 20 miles (32 km) south of Alpena. The road runs through rural, forested areas of Iosco and Alcona counties, inland from Lake Huron.
M-80 is a state trunkline highway in the Upper Peninsula of the US state of Michigan. It runs from Kinross to M-129 near Donaldson. The highway serves the site of the former Kincheloe Air Force Base and the current Chippewa County International Airport. The designation has been used twice before on roads in the Lower Peninsula in the 1910s through 1930s while the current usage dates back to the mid-1990s.
M-61 is a state trunkline highway in the US state of Michigan that runs between Marion and Standish. The highway runs along the boundary area between Northern Michigan and Central Michigan in the Lower Peninsula. M-61 runs through rural forestland connecting several smaller communities together as it connects M-115, US Highway 127 (US 127), Interstate 75 (I-75) and US 23. Less than 10,000 vehicles a day use various segments of the roadway on average.
Business US Highway 41 was a state trunkline highway that served as a business loop off US 41 and M-28 in Marquette, Michigan, along Washington and Front streets. The streets serve the downtown area of Marquette and are bordered by several commercial properties and businesses. Those two streets originate with the early founding of the city in the middle of the 19th century. Jurisdiction over them was transferred to the city as part of a highway swap that resulted in the decommissioning of the trunkline in 2005. It was also previously co-designated Bus. M-28, mirroring the Bus. US 41/Bus. M-28 designation previously used along Bus. M-28 in Ishpeming and Negaunee. Washington and Front streets had been a part of the state highway system since the 1910s, and a part of the United States Numbered Highway System since 1926. The business loop designation dates back to the 1960s and was removed in 2005.
M-199 is a state trunkline highway near Albion in the US state of Michigan. The western terminus of the 4.030-mile-long (6.486 km) road is in Sheridan Township at exit 119 off Interstate 94 (I-94). The eastern terminus is a junction with Business Loop I-94 downtown Albion. The entire road is within Calhoun County and runs through rural farm fields outside of Albion; in town it is a residential street. The M-199 designation had previously been applied to a highway in the Upper Peninsula in the 1930s. The current highway was previously part of other highways in the first half of the 20th century before it was transferred to local control around 1960. It was later transferred back to state control in 1998 and remains unchanged since.
M-67 is a north–south state trunkline highway in the Upper Peninsula of the U.S. state of Michigan. It connects with US Highway 41 (US 41) and M-94 between Trenary and Chatham. The highway has largely been unchanged during its history, although the highways that connect to M-67 on each end have changed several times.
M-82 is a state trunkline in the Lower Peninsula in the US state of Michigan that travels between Fremont and Howard City. The section between Newaygo and Howard City travels through Fremont and along the southern edge of Manistee National Forest. The current version of M-82 is actually the second in the state; the first usage appeared in the Upper Peninsula by 1919. The Lower Peninsula routing has been in use since the 1920s. Various extensions and truncations have shifted the terminus as far west as New Era or Hesperia in the past. The current route was finalized in the late 1970s
M-83 is a north–south state trunkline highway in the Lower Peninsula of the US state of Michigan primarily serving as a link between Interstate 75/US Highway 23 (I-75/US 23) in Birch Run, including a short east–west section with M-54, and the Bavarian-themed town of Frankenmuth. M-83 is primarily a north–south trunkline that passes by such landmarks as Bronner's Christmas Wonderland, Zehnder's and the Bavarian Inn before leaving town. The landscape in the remainder of the area is composed of farm fields between Frankenmuth and the northern terminus at M-15 near Richville.
M-87 is the designation of a former state trunkline highway in the Lower Peninsula of the US state of Michigan, which prior to 1960 ran east–west between the towns of Fenton and Holly. The highway served as a connector between US Highway 23 (US 23) and the former routing of US 10, which ran along what is now the Interstate 75 (I-75) corridor. The highway connected the downtown areas of each community as well as running through then-rural areas of Genesee and Oakland counties. The trunkline was decommissioned in late 1960, removing it from the system.
M-222 is the current designation of a state trunkline highway in Allegan County of the US state of Michigan. It runs between the city of Allegan, where it connects with M-40/M-89, and the US Highway 131 (US 131) freeway near Martin. The highway runs along a series of streets in Allegan and through rural farm fields and woods between the two communities along 116th Avenue. The roadway was a state highway back in 1919 when the system was initially signed. It was assigned as part of M-89 and M-40 before being given its own number, M-118. That designation was applied to the highway until 1988 when that was retired in favor of the current M-222.
US Highway 31 (US 31) is a part of the United States Numbered Highway System that runs from Alabama to the Lower Peninsula of the US state of Michigan. In Michigan, it is a state trunkline highway that runs from the Indiana–Michigan state line at Bertrand Township north to its terminus at Interstate 75 (I-75) south of Mackinaw City. Along its 355.2-mile-long (571.6 km) route, US 31 follows the Michigan section of the St. Joseph Valley Parkway as well as other freeways and divided highways northward to Ludington. North of there, the trunkline is a rural undivided highway through the Northern Michigan tourist destinations of Traverse City and Petoskey before terminating south of Mackinaw City. Along its route, US 31 has been dedicated in memory of a few different organizations, and sections of it carry the Lake Michigan Circle Tour (LMCT) moniker. Four bridges used by the highway have been recognized for their historic character as well.
There have been six business routes of Interstate 96 (I-96) in the US state of Michigan. There are two business loops designated Business Loop Interstate 96 : one through Lansing and one through Howell. Both follow the old route of US Highway 16 (US 16), with appropriate connections to I-96. There are three former business spurs that were designated Business Spur Interstate 96. One connected to the carferry docks in Muskegon, running concurrently with part of Business US 31 along former US 16, but it has been eliminated. The second spur ran into downtown Portland until it was decommissioned in 2007. Two routes in the Detroit area—a loop through Farmington and a spur into Detroit—both using Grand River Avenue, and meeting at the temporary end of I-96 near Purdue Avenue, were eliminated when I-96 was moved to the completed Jeffries Freeway in 1977. The Farmington business route is still state-maintained as an unsigned highway, while the Detroit business route remained unsigned until it was decommissioned in 2016 and replaced by an extension of M-5.
There have been seven business routes of US Highway 31 in the state of Michigan. All of the business routes are former sections of US Highway 31 (US 31). They connect the freeway mainline of US 31 to the various downtowns of cities bypassed by US 31. Two of the current business routes, for Hart and Ludington, are business spurs, connecting to US 31 on only one end, while the remainder for Muskegon, Whitehall–Montague and Pentwater, are business loops. The two former routes, for Niles and Holland were a business spur and loop, respectively.
M-24 in Holton 
M-11 in Hart 
