Since the freeway was completed in 1973, a few changes have been made to I-75 in Michigan. From 1973 to 1975, I-75 was widened from four to six lanes from south of Flint to north of Bay City. MDOT truncated US 2 to end in St. Ignace by removing it from the I‑75 freeway in 1983. In 1986, US 10 was truncated to Bay City, removing its concurrency with I-75 from there to Clarkston. Two years later, the original bascule Zilwaukee Bridge across the Saginaw River was replaced by a much higher structure slightly north of the former bridge. All of I-75 within Michigan was named the Tuskegee Airmen Memorial Highway, in honor of the Tuskegee Airmen, at the end of December 2014. In May 2017, MDOT raised the speed limit on I-75 between Bay City and Sault Ste. Marie, excluding the Mackinac Bridge, from .