M-37 over Muskegon River
Newaygo County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M-37 over Muskegon River in Newaygo 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 1953 and reconstructed in 2000, making it 72 years old at the 2025 inventory.
- It carries about 15,989 vehicles a day (traffic count year 2007).
- Its listed owner is the state highway agency.
- It is one of 32 of the 66 inventoried bridges in Newaygo County rated fair (48.5%); 6 (9.1%) 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 June 2024, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- 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 → (43.42321, -85.79823)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Steel girder and floorbeam |
| Length | about 555 ft |
| Location | In Newaygo |
| NBI structure number | 000000000007723 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Newaygo County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| M-37 over CSX RR Penoyer Creek | 1984 | 6,835 | Fair |
| M-37 over White River | 1928 | 6,100 | Fair |
| M-82 over CSX RR and Penoyer Creek | 1986 | 5,811 | Good |
| M-120 over Braton Creek | 1935 | 5,638 | Fair |
| M-20 over White River | 1970 | 4,400 | Fair |
| Muskegon Drive over Little Muskegon River | 1958 | 3,300 | Good |
All bridges nearby: Newaygo County, MI bridge conditions · every bridge in Newaygo County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.