MACKINAW ROAD OVER US-10
Spicer Group provided as-needed construction inspection, construction administration, and materials testing services to the Michigan Department of Transportation’s (MDOT) Bay City Transportation Service Center (TSC) for the project to replace the Mackinaw Road bridge over US-10 in Bay County. The project also included reconstruction of the adjacent ramps and the construction of two new roundabouts at the ramp terminals to improve traffic flow and reduce crash potential.
This $32.8 million project began in April 2024 with the full demolition of the existing Mackinaw Road bridge, originally constructed in the 1950s. Crews removed the entire structure, including both abutments, before constructing new Geosynthetic Reinforced Soil–Integrated Bridge System (GRS-IBS) abutments. These GRS abutments allow faster construction, reduce cost, improve settlement performance, and provide a smoother transition between the roadway and bridge deck. Their modular makeup also minimizes long-term maintenance and improves service life compared to traditional cast-in-place abutments.
Following completion of the new bridge, construction shifted to the two roundabouts at the ramp terminals. These modern roundabouts replaced the former signalized intersections, improving traffic operations, reducing queuing during peak travel hours, and enhancing safety by lowering conflict points and crash severity.
The project reached substantial completion and reopened to traffic in late 2024. Throughout construction, Spicer Group supported MDOT by providing construction administration, daily inspection, materials testing, and professional survey services to ensure that all work met MDOT specifications and performance requirements.
PROJECT INFORMATION
Location
Auburn, MI
Spicer Group Project Contact
Nathan Pfenninger, PE
989-225-3760
PROJECT PHOTOS
