Tuesday (April 19th) the Michigan Department of Transportation (MDOT) will be investing $3.3 million to upgrade I-75 north of St. Ignace to south of Sault Ste. Marie. Work includes about 57 miles of freeway sign upgrades, overhead sign structures, guardrail upgrades, and reflective roadside delineators. A minimum of one lane will be open at all times on northbound and southbound I-75. All work will be performed during daytime hours. Work will require intermittent shoulder or single-lane closures. A 12-foot lane width restriction will be in effect. The work is expected to be done by October 14th.