To extend the life of its bridge assets, the Michigan Department of Transportation (MDOT) completes routine in-depth condition assessments, or scoping inspections, throughout the State to determine appropriate maintenance or repair strategies for given structures. MDOT’s Metro Region encompasses Macomb, Oakland, and Wayne Counties, and is responsible for 1,389 structures. As part of the Metro Region’s current bridge scoping program for the 2024 construction season, MDOT retained Wade Trim to evaluate 13 bridges: seven within the I-94 and M-10 interchange, four near the I-75 and M-8 (Davison Freeway) interchange, and two on M-53 over the Clinton River.

A top-down inspection approach—from deck surface to bearings and substructures—is used to locate, identify, and quantify deficiencies throughout each structure. Scoping inspections reveal deterioration such as cracking and delamination, or separation, of the concrete; spalling, or concrete section loss; steel section loss; and degradation to protective coating of concrete and steel elements. For structures that span waterways, scour inspections are performed around substructures submerged in water. Drones are used to capture high-definition images of bridge decks in coordination with design software that helps map out and quantify deck deficiencies.

Heavy traffic throughout these areas required a detailed maintenance of traffic plan to minimize the disruption to commuters. Close coordination with MDOT’s Traffic and Safety engineers was necessary to accommodate the shoulder, lane and ramp closures, and to coordinate roadway closures with nearby construction projects.

After the bridge scoping inspections are completed, reports with recommendations for any needed repairs, rehabilitation and/or reconstruction of the bridge elements will be submitted to MDOT in late 2019.