Michigan officials are banning most vehicles from the Mackinac Bridge during the annual Labor Day bridge walk because of concerns about terrorism.
Tens of thousands of people join the annual walk across the nearly 5-mile-long bridge, which links Michigan's two peninsulas where Lakes Huron and Michigan meet.
Walkers use two lanes on the bridge, while the other two have been reserved for vehicles.
Under the policy announced Tuesday, the only vehicles allowed between 6:30 a.m. and noon will be buses carrying walkers. That likely means a huge traffic tie-up, but officials say safety must come first.
Col. Kriste Kibbey Etue (eh-tyoo) of the Michigan State Police says there are no known threats against the bridge walk.
But terrorists in a number of locations have driven vehicles into large crowds.
