M-72|m-93 over Au Sable River
Crawford County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M-72|m-93 over Au Sable River in Crawford 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 1993, making it 32 years old at the 2025 inventory.
- It carries about 11,731 vehicles a day (traffic count year 2007).
- Its listed owner is the state highway agency.
- It is one of 40 of the 55 inventoried bridges in Crawford County rated fair (72.7%); 6 (10.9%) 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 June 2023, 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 → (44.65802, -84.72608)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 54 ft |
| Location | In Grayling |
| NBI structure number | 000000000002053 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2023 |
| 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 Crawford County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-75bl|m-72|n Jame over Au Sable River | 1935 | 13,375 | Fair |
| I-75 SB over S Grayling Rd | 1970 | 11,000 | Fair |
| I-75 NB over S Grayling Rd | 1970 | 11,000 | Fair |
| I-75 NB over E Br Au Sable River | 1961 | 9,772 | Fair |
| I-75 NB over Lewiston Grade Road | 1961 | 9,772 | Fair |
| I-75 SB over Lewiston Grade Road | 1961 | 9,772 | Fair |
All bridges nearby: Crawford County, MI bridge conditions · every bridge in Crawford County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.