Why Are Some Michigan Roads Known as ‘Trunk Lines?’

Numbered highways in Michigan are officially known as 'Trunk Lines.' How did they gain that silly name what exactly does it mean?

The name is European in origin. Highways in England, Ireland, France and Sweden are known as Trunk Roads. The 'trunk' name is much less common in the United States with only three states, all in the upper Midwest, that call their highways Trunk Lines - Michigan, Wisconsin and Minnesota.

Officially, all the roads maintained by the State Department of Transportation (Interstate, US and State highways) are known as the Michigan State Trunkline Highway System.

The system dates back to 1913 and today includes 9669 miles of roads across the state.

Even though no one ever calls Michigan highways trunklines, know that's what you're officially traveling on as you drive around our peninsulas.

The longest trunkline in the state is Interstate 75 running 395 miles from the international border at Sault Ste Marie to the Ohio line near Toledo.

As for the shortest highway, officially it's Business Spur I-375 in Detroit - it's unsigned and runs just 0.17 miles along Jefferson Ave near the Windsor Tunnel entrance. The shorted signed road in the state is M-212 at 0.7 miles in Aloha.

With routes along the state trunkline system like the Tunnel of Trees (M-119) and the iconic M-22 near Sleeping Bear Dunes, there are some memorable drives in Michigan. Here are more iconic roads across America worth the drive.