 In November 1960, sections of freeway opened from Indian River north to the southern Mackinac Bridge approaches in Mackinaw City and from St. Ignace to Evergreen Shores, and by December, the section of freeway running between Evergreen Shores and M‑123 was scheduled to open.In 1961, the MSHD had proposed that the section of I-75 south of Detroit to Toledo be built as an electronic highway under a bid through General Motors; the testing for such a roadway was ultimately done at Ohio State University instead.That same year the original Zilwaukee Bridge, a bascule bridge across the Saginaw River was opened along with a section of freeway north to Kawkawlin.