M-15 over Cass River
Tuscola County, Michigan · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M-15 over Cass River in Tuscola 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 2015, making it 10 years old at the 2025 inventory.
- It carries about 14,550 vehicles a day (traffic count year 2013).
- Its listed owner is the state highway agency.
- It is one of 82 of the 241 inventoried bridges in Tuscola County rated good (34.0%); 10 (4.1%) 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 November 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 → (43.3709, -83.58076)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 9 | 9 | Excellent condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 310 ft |
| Location | In Vassar |
| NBI structure number | 000000000010410 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | November 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 Tuscola County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| M-46 over Cheboygan & Branches Drn | 1939 | 6,701 | Poor |
| M-81 over Marsh Drain | 2007 | 6,273 | Good |
| M-25 over Quanicassee River | 2013 | 5,571 | Good |
| M-25 over (no Name) Drain | 1932 | 5,571 | Fair |
| M-25 over Wisner Drain | 1985 | 5,571 | Fair |
| M-25 over Allen Drain | 1985 | 5,571 | Fair |
All bridges nearby: Tuscola County, MI bridge conditions · every bridge in Tuscola County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.