American Highway Code US Route 31 History
. During 1930s, US 31 continued at Saint Ignace across the Straits of Mackinac, and junctioned all the way through U.S. Route 2 (Mackinac Trail and what later became M-123).
. Before the Interstate era, US 31 were a foremost north-south highway. Interstate 65 supplants US 31 and moreover 31W or 31E as a through route between Indianapolis along with Mobile.
. South of Indianapolis, all segments of US 31 not coinciding with Interstate 65 have been reduced to roads largely of local use. Interstate 196 now carries the route of US 31 between Holland, Michigan, and St. Joseph, Michigan.
. All of US 31 between Ludington, Michigan, and Indianapolis, Indiana, is divided highway -- a little of it is freeway, which include a bypass route of South Bend (Indiana). The fragment between South Bend and Indianapolis has been scheduled for upgrade or surrogate with Interstate-standard freeway (see U.S. Route 31 in Indiana).
. Environmental impact studies shows that the fifth phase of the then-to-be-constructed freeway segment among Napier Avenue near Benton Harbor (Michigan) and I-94 may not be complete until 2015.
. The segment of I-75 north of US 31's northern terminus on the way to the Mackinac Bridge was designated US 31 prior to the 1990s and was US 31's the majority of the northern portion is been built to freeway status. Ever since its truncation at the I-75 junction, on the other hand, the most northern segment of US 31 freeway ends close to Ludington.
. On the southern end, US 31 originally went further west than it currently does, passing through Spanish Fort (Alabama). It crossed Mobile Bay passing through several narrow bridges, with the Admiral Raphael Semmes Bridge, a drawbridge across the TensawRiver.
. It turned north all along the east bank of the Mobile River and cresses the river into Plateau (Alabama), above the Cochrane Bridge (removed), another old drawbridge where the current Cochrane-Africatown USA Bridge is now situated. It then turned south to end at U.S. Route 90. It is now officially ends at U.S. Route 98 in Spanish Fort (Alabama).
