**Traffic changes announced for 2017 Annual Mackinac Bridge Walk** - Citing safety and security recommendations by the Michigan State Police and U.S. Department of Homeland Security, the Mackinac Bridge Authority will close the bridge to most vehicle traffic during the 2017 Annual Bridge Walk on Labor Day. Please plan your travel accordingly. - Unites Michigan's upper and lower peninsulas. The Mackinac Bridge is the longest suspension bridge in the Western Hemisphere with 7,400 feet of roadway suspended in the air over the straits of Mackinac. Total length of the bridge, including its approaches, is approximately five miles. Celebrate 50 years with the mighty Mac with the Michigan History Magazine. Click on the link for more information.