The toll plaza on the St. Ignace side of the Mackinac Bridge is at I-75 MM 344, and the toll plaza of the International Bridge is on the Michigan side just north of MM 394, meaning that the two bridges are just over 50 miles apart; at 70 miles per hour, the posted speed on I-75, you can drive between the two points in less than 45 minutes.

As far as the International Bridge being a "short little thing", it is actually close to 3 miles long, as it crosses (1) a canal that makes the downtown portion of Soo Michigan into an island; (2) the twin channels of the Soo Locks on the Michigan side; (3) the main channel of the St. Mary's River, which is where the cataracts are; (4) Whitefish Island, which is part of Canada; (5) the Sault Ste. Marie Canal, which has a lock used by pleasure craft; and (6) the northernmost channel of the St. Mary's River. It is a two lane viaduct for most of its length, with a twin steel truss span over the Soo Locks; and a single steel truss span near the north end of the bridge.