US-31 Br SB over S Br Muskegon River
Muskegon County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US-31 Br SB over S Br Muskegon River in Muskegon County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1964, making it 61 years old at the 2025 inventory.
- It carries about 11,592 vehicles a day (traffic count year 2007).
- Its listed owner is the state highway agency.
- It is one of 99 of the 143 inventoried bridges in Muskegon County rated fair (69.2%); 16 (11.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated April 2024, on a 24-month routine inspection cycle.
- 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 → (43.25377, -86.22869)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 104 ft |
| Location | In Muskegon |
| NBI structure number | 000000000007635 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Muskegon County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-31 over I-96 | 1959 | 62,644 | Fair |
| US-31 NB over Mi Shore RR & Laketon Av | 1960 | 32,065 | Fair |
| US-31 NB over Black Creek | 1959 | 31,322 | Fair |
| US-31 SB over Black Creek | 1949 | 31,322 | Fair |
| I-96 over Hile Rd | 1961 | 31,000 | Fair |
| I-96 EB over Airline Road | 1961 | 29,245 | Fair |
All bridges nearby: Muskegon County, MI bridge conditions · every bridge in Muskegon County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.