Brennan Road over Sullivan Drain

St. Clair County, Michigan · rated Fair in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

• Brennan Road over Sullivan Drain in St. Clair County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
• It was built in 1971, making it 54 years old at the 2025 inventory.
• It carries about 51 vehicles a day (traffic count year 1994).
• Its listed owner is the county highway agency.
• It is one of 165 of the 326 inventoried bridges in St. Clair County rated fair (50.6%); 31 (9.5%) are rated poor.
• A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

View this bridge on a map → (43.02308, -82.74965)

Component ratings

Bridge details

Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.

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Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.