The Mackinac Bridge (“The Mighty Mac”)
The Mackinac Bridge is located on Interstate – 75 in Northern Michigan at the Straits of Mackinac. The bridge connects Michigan’s Upper and Lower Peninsulas. Mackinaw City is located at the south end of the bridge. St. Ignace is located at the north end of the Mackinac Bridge.
The Mackinac Bridge is currently the fifth longest suspension bridge in the world. In 1998, the Akashi Kaikyo Bridge in Japan became the longest with a total suspension of 12,826 feet. The Great Belt Bridge in Halsskov-Sprogoe, Denmark, which also opened in 1998, is the second longest suspension bridge in the world with a total suspension of 8,921 feet. The Mackinac Bridge is the longest suspension bridge in the western hemisphere.
The total length of the Mackinac Bridge is 26,372 feet. The length of the suspension bridge (including anchorages) is 8,614 feet. The length from cable bent pier to cable bent pier is 7,400 feet. Length of main span (between towers) is 3,800 feet.
All suspension bridges are designed to move to accommodate wind, change in temperature, and weight. It is possible that the deck at center span could move as much as 35 feet (east or west) due to high winds. This would only happen under severe wind conditions. The deck would not swing or “sway” but rather move slowly in one direction based on the force and direction of the wind. After the wind subsides, the weight of the vehicles crossing would slowly move it back into center position.