The Michigan Department of Transportation’s (MDOT) infrastructure network includes 54 bridges with deck areas exceeding 100,000 square feet or that are movable, segmented, or unique in their construction. MDOT maintains good bridge conditions, emphasizing capital scheduled/preventive maintenance and rehabilitation work instead of replacement to maximize value and longevity. Routine inspection and an in-depth scoping/condition assessment occur every 10 years. Wade Trim completed scoping for the Evergreen Road Bridge over CSX Railroad and I-96 in Detroit, and the M-64/M-38 Bridge spanning the Ontonagon River in the Upper Peninsula.

A comprehensive assessment of bridge elements was completed to identify and quantify concrete and steel deficiencies, such as concrete cracking, spalling, and delamination, as well as steel issues like corrosion, pack rust, section loss, cracking, and coating failures. Advanced planning and efficient execution were critical to accommodate the complex magnitude of bridge elements, maintain safety, and minimize traffic impacts.

A drone, bucket truck, and Reach-All were used to access and document bridge elements. Audible (sounding) and visual inspections were completed on all structural components, including a review of geometrics, ADA and current design standards, and compliance. Concrete and steel deficiencies were noted, marked, and photographed. Steel beams were also measured with ultrasonic thickness gauges to determine loss.

Field investigation findings were analyzed, and maintenance and repair options were developed, considering MDOT’s Bridge Deck Preservation Matrix, which guides recommended repair methods. Preferred alternatives for each bridge were prepared with detailed costs, structural life expectancy, repair effectiveness, regulatory compliance, and sound engineering judgment.