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Road & Highway Facts

Woodward Avenue construction in Detroit. Photo taken around 1936.
Department of Transportation

Road & Highway Facts

  • The first Michigan road map, with only three roads on it, was published by the United States Congress in 1826.
  • Michigan's first four-lane divided expressway, the Detroit Industrial Expressway, ran between Detroit and Willow Run in 1941.
  • The shortest state trunkline road is M-212 in Cheboygan County. It is only .7 mile long.
  • The longest highway in Michigan is I-75, which runs 395 miles from the Ohio border to the International Bridge in Sault Ste. Marie.
  • Michigan has a total of 120,256 miles of paved roadway (9,669 route miles of state trunkline, 89,444 route miles of county roads, and 21,198 route miles of city and village streets).
  • There is enough pavement in Michigan roadways to build a one-lane road from the Earth to the moon.
  • More than 95.1 billion miles are driven on Michigan roadways every year.
  • M-185 on Mackinac Island is the only state highway in the nation where motor vehicles are banned.
  • The shortest freeway in Michigan is I-375 in Detroit. It is only 1.1 miles long.
  • Eight Michigan highways began as Native American trails, US-2 (from Sault Ste. Marie to Green Bay); I-75 (from Detroit to Saginaw); I-94 (from Detroit to St. Joseph; I-96 (from Detroit to Grand Rapids); I-94 (from Detroit to Port Huron); US-41 (from L'Anse to Marquette); and US-12 (from Ypsilanti to Chicago).
  • The first surveyed road in Michigan was Pontiac Road (now called M-1 or Woodward Avenue) connecting Detroit and Pontiac in 1819.
  • The three-span US-12 camelback bridge in Mottville is Michigan's longest remaining bridge of this type.
  • One of the most unique bridges in Michigan is the siphon bridge carrying old US-2 over the Manistique River. The bridge deck is actually four feet below the water level, and has been featured in "Ripley's Believe it or Not!"
  • The first border-to-border concrete highway was M-16 from Detroit to Grand Haven in 1920.
  • There are 10,754 roadway bridges in Michigan. Of these, 4,411 are on the state highway system and 6,343 are located on county roads or city streets.
  • The statutory width of Michigan's road right of way is 66 feet, or two rods (33 feet), on each side of each section line.
  • The towers on the Mackinac Bridge (552 feet high) are almost as tall as the Washington Monument (555 feet high).
  • Adopt-A-Highway volunteers have removed more than 2 million bags of trash from state roadsides since the program began in Michigan in 1990. Approximately 3,178 citizen volunteer groups pick up trash three times a year on nearly 6,700 miles of state highways.
  • In 1956, Michigan became one of the first state highway departments to use a digital computer to perform highway computer programming work.