ZILWAUKEE, Mich – The Zilwaukee Bridge, a critical artery for Interstate 75 (I-75) traffic in Saginaw County, Michigan, is scheduled for a significant closure in 2025.
According to a March 10, 2025, press release from the Michigan Department of Transportation (MDOT), the southbound lanes of the bridge will be closed from April 14 to June 27 as part of a $2.9 million preventive maintenance project. This closure, affecting one of Michigan’s most iconic and heavily traveled bridges, is expected to disrupt commuters and vacationers alike, particularly those returning from northern Michigan destinations.
Details of the 2025 Closure MDOT’s $2.9 million investment will fund a range of maintenance tasks aimed at extending the lifespan of the Zilwaukee Bridge, which carries both I-75 and US-23 over the Saginaw River. The project includes expansion joint repairs, deck patching, and resealing, with work necessitating a full closure of the southbound lanes for over ten weeks.
Southbound traffic will be detoured onto I-675, a route that has historically served as a bypass during bridge maintenance. MDOT has also indicated that work on the northbound lanes is slated to begin July 14, though specific details about the duration and scope of that phase remain forthcoming as of this writing.
The agency emphasized the safety benefits of this closure, stating that it will “improve and extend the service life of the Zilwaukee Bridge” while providing “the safest work area possible for crews and motorists.” Economic modeling from MDOT suggests the project will directly and indirectly support 28 jobs, underscoring its broader impact on the region.
The Zilwaukee Bridge, completed in 1988, is no stranger to closures and construction challenges. Spanning approximately 8,000 feet and rising 125 feet at its highest point, the current high-level segmental concrete bridge replaced a problematic four-lane bascule (drawbridge) structure built in 1960. That earlier bridge, designed to accommodate Great Lakes freighter traffic, frequently caused massive traffic backups due to its repeated openings—over 300 times annually by 1986—prompting the need for a permanent solution.
Construction of the modern Zilwaukee Bridge began in 1978 but faced significant setbacks. In August 1982, a major accident occurred when a 300-foot-long, 6,700-ton segment tilted out of alignment, sagging five feet on one end and rising 3.5 feet on the other, due to improperly counterbalanced weight. This incident damaged a pier footing and halted construction, leading to a $6.8 million repair effort and the termination of the original contractor, Stevin Construction. A new contractor completed the bridge in 1988, but at a total cost of $127 million—far exceeding the initial $76.8 million bid.
MDOT officials have estimated the Zilwaukee Bridge’s lifespan at 80 to 100 years, meaning it could serve until at least 2068. A major update from 2013 to 2015 replaced original bearing pads, expected to last 25 to 50 years, suggesting the current maintenance is part of a long-term preservation effort. However, replacing the bridge entirely could cost upwards of $1 billion, according to a December 22, 2022, ClickOnDetroit article, making these repairs a cost-effective alternative.
For now, drivers should prepare for detours and potential delays starting April 14, 2025. As MDOT continues to maintain this engineering marvel—once dubbed “the perfect example on how not to build a bridge” by DangerousRoads.org—the Zilwaukee Bridge remains a testament to Michigan’s resilience in overcoming infrastructural challenges.
