St. Clair County, MI

St. Clair County Bridge Snapshot

St. Clair County, Michigan contains 14 public highway bridges in the FHWA National Bridge Inventory. Roughly 42.9% are rated “Good,” 28.6% “Fair,” 7.1% “Poor,” and 7.1% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in MI are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.