Forest Lake R FH79 over Au Train River
Alger County, Michigan · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Forest Lake R FH79 over Au Train River in Alger County, Michigan, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1977, making it 48 years old at the 2025 inventory.
- It carries about 500 vehicles a day (traffic count year 1995).
- Its listed owner is the county highway agency.
- It is one of 16 of the 53 inventoried bridges in Alger County rated good (30.2%); 7 (13.2%) 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 September 2023, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (46.41332, -86.84232)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 82 ft |
| Location | 1.44 Mi S of Au Train |
| NBI structure number | 000000000000060 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Alger County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| M-28 over Anna River | 1949 | 7,171 | Fair |
| East Munising Ave over Anna River | 1978 | 5,715 | Fair |
| M-28 over Au Train River | 1932 | 5,200 | Fair |
| US-41 over Huber Creek | 1987 | 3,609 | Fair |
| M-28 over Sand River | 1939 | 3,093 | Fair |
| M-28 over Laughing Whitefish River | 1939 | 3,093 | Good |
All bridges nearby: Alger County, MI bridge conditions · every bridge in Alger County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.