MDOT PSA | Falling ice closures are possible for the Mackinac Bridge

• When ice falls from the bridge’s towers and cables, the Mackinac Bridge Authority closes the bridge to traffic for safety.  
• Ice chunks, sheets and spears that fall hundreds of feet from the bridge’s towers and cables have damaged vehicles and have the potential to injure or kill vehicle occupants.
• Prior to this winter, the Mackinac Bridge has been closed due to falling ice 32 times since 1995, for an average duration of five hours and 54 minutes per closure.

ST. IGNACE, Mich. – Despite recent closures for falling ice, some ice remains on the upper cables and towers of the Mackinac Bridge, leading to the possibility of closing the bridge to traffic due to falling ice over the coming days.

Winds are expected to begin increasing on Friday in the Straits, and temperatures are predicted to rise above freezing after 11 a.m., potentially loosening accumulated ice.

When ice falls from the bridge’s towers and cables, the Mackinac Bridge Authority (MBA) closes the bridge to traffic for safety. Ice chunks, sheets and spears that fall hundreds of feet from the bridge’s towers and cables have damaged vehicles and have the potential to injure or kill vehicle occupants.

“It’s impossible to say when this ice could begin falling from the bridge, resulting in a closure, or if it could gradually melt without incident,” said Bridge Director Kim Nowack. “We want our customers to be aware of the possibility of closures and know how to find more information if they occur.”

This winter the bridge has already closed for falling ice four times, between Feb. 19 and Feb. 22, totaling about 18 hours.

A video released by the MBA and the Michigan Department of Transportation (MDOT) includes video footage and still images of garage door-sized sheets and 20-foot-long spears of ice shattering on the bridge deck to help explain why the bridge must be closed when ice is falling.

Mackinac County 911, using its RAVE Alert System, will send updates and information from the MBA to users’ cell phones any time the bridge has a partial or full closure due to weather or other conditions. Messages also will be sent when a full closure is reduced to a partial closure or when the bridge reopens to all traffic. To sign up, text “MacBridge” to 67283.

Details and updates are also available around the clock at www.MackinacBridge.org/Fares-Traffic/Conditions/ and on X at @MackinacBridge. The Michigan Department of Transportation (MDOT) posts information on closures on X, BlueSky, Threads, Facebook and www.Michigan.gov/Drive, as well as on freeway dynamic message signs.

The MBA has compiled a list of frequently asked questions about falling ice and other topics on its website.

Since 1995, when the MBA began tracking closures of the bridge for any reason, the bridge has been closed 32 times for falling ice, an average of about one each year, not including the current winter.

The shortest closure for falling ice was 37 minutes on Nov. 29, 2001. The longest closure to date was the April 2-3, 2025, closure when the bridge was closed for 30 hours and four minutes. As of May 2025, the average falling ice closure lasts about five hours and 54 minutes. Over the last 30 years (roughly 262,800 hours), the bridge has been closed 188 hours and four minutes for falling ice, less than 0.1 percent of the time.

Spanning the Straits of Mackinac since 1957