The St. Joseph Valley Parkway is a freeway in the U.S. states of Indiana and Michigan, serving as a bypass route around Elkhart, Mishawaka, and South Bend in Indiana and Niles in Michigan. The freeway runs to the south and west of Elkhart and South Bend and Niles and consists of segments of U.S. Route 31 (US 31) and US 20; those two highway designations run concurrently at the southwestern rim of the South Bend metropolitan area. It continues north to run along the St. Joseph River valley.
M-62 is an arc-shaped state trunkline highway in the southwestern part of the US state of Michigan. The highway runs from the Indiana state line north and west to M-140 in Eau Claire. In between, it serves the western Cass County communities of Dowagiac and Cassopolis. The highway was formed in the 1920s, originally as a north–south route. It was later extended, taking the current arc-shaped routing. A short truncation in the 1950s produced the current routing, which has remained unchanged since. In total, M-62 runs about 28+1⁄3 miles (45.6 km) in the two counties.
M-103 is a state trunkline highway entirely within St. Joseph County in the southwestern region of the U.S. state of Michigan. The trunkline runs between U.S. Highway 12 (US 12) in Mottville and the Indiana state line along undivided highway near the St. Joseph River. With the connection to State Road 15 (SR 15), it provides access to the Indiana Toll Road. The current highway is the second to carry the number; the first version of M-103 has been incorporated into the routing of US 131.
M-205 was a state trunkline highway in the US state of Michigan. The route was turned back to local control in October 2002 by the Michigan Department of Transportation (MDOT) after the completion of M-217. MDOT swapped roadways with the Cass County Road Commission ending the 67-year history of M-205.
M-40 is a north–south state trunkline highway in the Lower Peninsula of the US state of Michigan. The highway runs from US Highway 12 (US 12) near the Indiana state line in Porter Township north through Paw Paw and Allegan to end in the outskirts of Holland. The current northern end is near Interstate 196 (I-196) at an intersection with US 31/Business Loop I-196 (BL 196). In between, M-40 runs through mixed agricultural and forest lands and along lakes and rivers through Southwest Michigan.
M-51 is a north–south state trunkline highway in the southwestern portion of the US state of Michigan. The southern terminus is at a connection with State Road 933 across the Michigan–Indiana state line near South Bend, Indiana. From there the trunkline runs north through an interchange with US Highway 12 (US 12) into Niles along a route that was once part of Business US 12. North of Niles, the highway runs parallel to a river and a rail line through rural areas. The northern terminus is on Interstate 94 (I-94) west of Paw Paw.
M-53 is a north–south state trunkline highway in the US state of Michigan that connects Detroit to The Thumb region. The highway starts in Detroit at a connection with M-3 and ends in Port Austin, Michigan at M-25. In between, the trunkline passes through the northern suburbs of Metro Detroit, connects to freeways like Interstate 69 (I-69) and provides access to rural farmland. In Macomb County, M-53 follows the Christopher Columbus Freeway and POW/MIA Memorial Freeway, while the remainder of the highway is known as Van Dyke Avenue in the metro area or Van Dyke Road elsewhere. The highway has also been named the Earle Memorial Highway for one of the pioneers of the Good Roads Movement and Michigan's highway system.
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-143, also known as Michigan Avenue, is a previously unsigned spur state trunkline highway in the south central region of the US state of Michigan. The M-143 portion of Michigan Avenue runs from the East Lansing city limit to a junction with M-43 at Grand River Avenue. This highway is the second time that there has been an M-143 in Michigan. The first was a connection to the original Cheboygan State Park. The current is a remnant of M-43 in the Lansing area.
Business M-28 is a state trunkline highway serving as a business route that runs for approximately 4.9 miles (7.9 km) through the downtown districts of Ishpeming and Negaunee in the US state of Michigan. The trunkline provides a marked route for traffic diverting from U.S. Highway 41 (US 41) and M-28 through the two historic iron-mining communities. It is one of three business loops for M-numbered highways in the state of Michigan. There have previously been two other Bus. M-28 designations for highways in Newberry and Marquette.
M-81 is an east–west state trunkline highway in the Lower Peninsula of the US state of Michigan. The trunkline travels from the city of Saginaw at the junction with M-13 to the junction with M-53 east of Cass City over the county line in Greenleaf Township in northwestern Sanilac County in The Thumb area of the state. Outside of the cities and villages along its route, M-81 passes through mostly rural farm country. Near Saginaw it intersects the freeway that carries both Interstate 75 (I-75) and US Highway 23 (US 23) in an industrial area.
M-139 is a state trunkline highway entirely within Berrien County in the US state of Michigan. The highway starts at US Highway 12 (US 12) southwest of Niles and runs through rural areas of the county to terminate at an intersection with Business Loop Interstate 94 in Benton Harbor. The highway runs parallel to the St. Joseph River, crossing the river several times as it follows a set of roads previously used for US 31 in the area. The highway was first designated in the 1930s as a bypass of the Benton Harbor and St. Joseph area. Its termini have been moved over the years since, extending and contracting the length of the highway between Niles and Benton Harbor. M-139 now serves to provide access through the area from a set of bypasses consisting of I-94 and US 31.
M-140 is a north–south state trunkline highway in Berrien and Van Buren counties of the US state of Michigan. The highway starts in the Niles area at M-139 and runs north through Watervliet to South Haven, ending at Interstate 196/US Highway 31 (I-196/US 31). In between, it runs through farm fields and past lakes in the southwestern part of the Lower Peninsula. The trunkline is used, on average, by between 1,500 and 10,200 vehicles.
M-152 is a state trunkline highway in the US state of Michigan in Cass and Van Buren counties. The highway runs through the Sister Lakes area providing access to the lake cabins and adjoining farmlands. The highway has existed mostly unchanged since the designation was commissioned in the 1930s.
US Highway 12 (US 12) is an east–west United States Numbered Highway that runs from Aberdeen, Washington, to Detroit, Michigan. In Michigan, it runs for 210 miles (340 km) between New Buffalo and Detroit as a state trunkline highway and Pure Michigan Byway. On its western end, the highway is mostly a two-lane road that runs through the southern tier of counties roughly parallel to the Indiana state line. It forms part of the Niles Bypass, a four-lane expressway south of Niles in the southwestern part of the state, and it runs concurrently with the Interstate 94 (I-94) freeway around the south side of Ypsilanti in southeastern Michigan. In between Coldwater and the Ann Arbor area, the highway angles northeasterly and passes Michigan International Speedway. East of Ypsilanti, US 12 follows a divided highway routing on Michigan Avenue into Detroit, where it terminates at an intersection with Cass Avenue.
US Highway 33 (US 33) is a part of the United States Numbered Highway System that was once located in Berrien County, Michigan. At the time it was removed from the state, it was only about 2.8 miles (4.5 km) long running north from the Indiana state line to an intersection with US 12 south of Niles. The highway was not originally part of the US Highway System in the state; it was added in 1938 as a second designation for part of US 31 between the state line and St. Joseph. It was later extended further north to the community of Lake Michigan Beach. This extension became the only section of US 33 that was routed independent of another highway until it was truncated to Niles. In 1997, US 33 was officially removed from the state.
CR 17 at Indiana state line
US 12 near Union 
