Location: I-75 and US-23, Mackinaw City Reassurance shield after the 23 split. At one point, this was concurrent with US-31, but its southern terminus was shifted southwards. Location: I-75 and Mackinaw Hwy, Emmet Cty Reassurance shield as Mackinaw Hwy (old 31) traffic merges onto I-75 without access from I-75. Location: I-75 and US-31, Emmet Cty … Continue reading Interstate 75, US-23 to US-31