U.S. Route 23 in Michigan

US Highway 23
US 23 highlighted in red
Route information
Maintained by MDOT
Length	362.152 mi[1] (582.827 km)
Existed	November 11, 1926 (1926-11-11)[2]–present
Tourist routes	Lake Huron Circle Tour Huron Shores Heritage Route
Major junctions
South end	US 23 / US 223 near Lambertville
Major intersections	I-94 near Ann Arbor I-96 in Brighton I-75 near Flint I-69 in Flint US 10 in Bay City I-75 near Standish
North end	I-75 near Mackinaw City
Location
Country	United States
State	Michigan
Counties	Monroe, Washtenaw, Livingston, Genesee, Saginaw, Bay, Arenac, Iosco, Alcona, Alpena, Presque Isle, Cheboygan, Emmet
Highway system
United States Numbered Highway System List Special Divided Michigan State Trunkline Highway System Interstate US State Byways
← M-22 → Bus. US 23

US Highway 23 (US 23) is a north–south United States Numbered Highway that runs from Jacksonville, Florida, to Mackinaw City, Michigan. In the US state of Michigan, it is a major, 362-mile-long (583 km), north–south state trunkline highway that runs through the Lower Peninsula. The trunkline is a freeway from the Michigan–Ohio state line near Lambertville to the city of Standish, and it follows the Lake Huron shoreline from there to its northern terminus. Serving the cities of Ann Arbor and Flint, US 23 acts as a freeway bypass of the Metro Detroit area. Overall, the highway runs through rural areas of the state dominated by farm fields or woodlands; some segments are urban in character in the Ann Arbor, Flint and Tri-Cities areas. The section from Flint north to Standish also carries Interstate 75 (I-75) along a concurrency that includes a segment that carries almost 70,000 vehicles on a daily basis.

The first transportation routes along what is now US 23 in the state were sections of two Indian trails. In the early 20th century, four different auto trail names were applied to roads now a part of the highway. These roads were included as part of two state highways in the initial state highway system in 1919. When the United States Numbered Highway System was first designated on November 11, 1926, the new US 23 replaced the other designations along its route. Since creation, the road has been moved and realigned several times. Through the 1930s and 1940s, the lakeshore routing was created to replace a path that ran further inland through the northern portion of the state. Starting in the early 1950s, various sections in the southeastern and central areas of the Lower Peninsula were upgraded to freeways, bypassing several major cities in the area. These improvements were completed by the end of the 1960s. Since then a new crossing of the Saginaw River at Zilwaukee was built to replace a drawbridge that carried the I-75/US 23 freeway over a shipping channel.

Various memorial or tourist route designations have been applied to US 23 in the state since the 1980s. The highway has been a part of the Lake Huron Circle Tour since the creation of the Great Lakes Circle Tours in 1986. The non-freeway section was designated the Sunrise Side Coastal Highway by the Michigan Department of Transportation (MDOT) in 2004 as a part of what is now the Pure Michigan Byway Program. Since 2009, it has been called the Huron Shores Heritage Route. The highway has also carried two memorial designations related to war veterans and a third related to local civic leaders since a 2001 consolidation of related legislation in the state. MDOT has listed two of the highway's bridges on its historic bridge list, one of which is also on the National Register of Historic Places (NRHP). Future improvements to the route of US 23 include a proposed northerly extension of the freeway from Standish to one of several locations along the Lake Huron shoreline. Another freeway has been proposed in the Flint area that could connect US 23 directly to the south end of I-475.