michigan highway state trunkline highway lower_peninsula state michigan generally ran north port shoreline thumb region turning inland highway crossed thumb ran shoreline running inland terminating original state highways renumbered highways designation process route description started ran northward shoreline way western terminus reaching town original merged north ran concurrently westward turning inland highways separated north turned southward continued thumb bad axe ran concurrently town highway carried westward trunkline turned southwesterly follow road passed turning inland running southward highway turned alternately westward southward ran west road connection highways ran concurrently south separated turned westward northern terminus downtown intersection history state highway system signed original originally running northward port westward approved november decommissioned favor alternate numbers port north extended replacement segment west bay port renumbered bad axe west additionally remainder numbered major intersections
M-31 (Michigan highway)