If you live in Michigan there's a good chance you've taken some long road trips on a highway that stretches from Grand Rapids to Detroit or from the Michigan/Ohio border all the way up to the International Bridge in Sault Ste. Marie

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Out of all the highways in Michigan, there's one that holds the title of being the busiest, longest, and oldest.

Michigan's Busiest Highway Is Also It's Longest And Oldest

That honor goes to Interstate 75 (I-75) which runs north–south from Sault Ste. Marie in the Upper Peninsula to Miami, Florida.


In Michigan, I-75 enters from Ohio in the south, north of Toledo, and runs generally northward through Detroit, Pontiac, and Bay City, crossing the Mackinac Bridge and ending at the Canadian border in Sault Ste. Marie.

How Long Is I-75 In Michigan?


Interstate 75 covers approximately 396 miles in Michigan, which takes you through various landscapes, including farmland, forests, suburban communities, and the urban core of Detroit.

Mackinac Bridge
Photo by Aaron Burden on Unsplash

It also utilizes three of the state's monumental bridges to cross major bodies of water.

The History of I-75

The history of I-75 in Michigan dates back to the 1950s, with the start of the Detroit-Toledo Expressway in southern Wayne County.

The highway's completion and opening to traffic in various segments, particularly in the Detroit area, occurred between 1970 and 1973.

The highway was completed in Michigan on November 1, 1973, and it is the state's longest route-numbered highway.

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