Knab Rd over Otter Creek
Monroe County, Michigan · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Knab Rd over Otter Creek in Monroe County, Michigan, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1964, making it 61 years old at the 2025 inventory.
- It carries about 360 vehicles a day (traffic count year 2017).
- Its listed owner is the county highway agency.
- It is one of 40 of the 299 inventoried bridges in Monroe County rated poor (13.4%); 40 (13.4%) are rated poor.
- Its traffic status in the 2025 inventory is open, would be posted or closed except for temporary shoring or other temporary measures (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated September 2024, on a 12-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (41.85044, -83.42957)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 4 | 4 | Poor condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 104 ft |
| Location | .05 Mi N of S Otter Ck Rd |
| NBI structure number | 000000000007242 |
| Condition class | Poor |
| Traffic status (item 41) | Open, would be posted or closed except for temporary shoring or other temporary measures |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Monroe County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-75 over Conrail Raisin R Front | 1955 | 67,800 | Poor |
| I-75 over NS & Cn Railroad | 1956 | 65,200 | Good |
| I-75 over Norfolk Southern RR | 1955 | 65,200 | Fair |
| I-75 over Sandy Creek Rd | 1955 | 65,200 | Fair |
| I-75 over Paper Co Water Mains | 1955 | 63,962 | Fair |
| I-75 over Norfolk Southern RR | 1955 | 63,962 | Fair |
All bridges nearby: Monroe County, MI bridge conditions · every bridge in Monroe County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.