Route 415 over Tahquamenon River
Luce County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Route 415 over Tahquamenon River in Luce County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1974, making it 51 years old at the 2025 inventory.
- It carries about 40 vehicles a day (traffic count year 2016).
- Its listed owner is the county highway agency.
- It is one of 13 of the 28 inventoried bridges in Luce County rated fair (46.4%); 4 (14.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: substructure 7 to 6.
- Its most recent inspection on record is dated October 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 → (46.36332, -85.6857)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 6 | Satisfactory condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 86 ft |
| Location | 2 Mi. N. Mc Millan |
| NBI structure number | 000000000005917 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 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 Luce County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| M-28 over E Br Teaspoon Creek | 1993 | 3,756 | Fair |
| M-28 over W Br Sage River | 2001 | 2,127 | Fair |
| M-28 over E Br Sage River | 1959 | 2,127 | Fair |
| M-28 over E Br Fox River | 1989 | 1,763 | Fair |
| Dollarville Road over Teaspoon Creek | 1951 | 1,700 | Fair |
| County Rd 98 over Helmer Creek | 2005 | 1,200 | Good |
All bridges nearby: Luce County, MI bridge conditions · every bridge in Luce County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.