US-31 NB over Black River
FairOttawa County, Michigan · 0.4 MI N of M-21 · Structure no. 000000000008689
- Built
- 1949
- 76 years old, rebuilt 1984
- Condition
- Fair
- inspected May 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 240 ft
- 3 main spans
- Daily traffic
- 23,373
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
US-31 NB over Black River is a steel continuous stringer/multi-beam or girder carrying US-31 NB over Black River in Ottawa County, Michigan. It was built in 1949 and reconstructed in 1984, so it is 76 years old, older than the Michigan average of 48.3 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 23,373 vehicles a day, roughly 7% of them trucks, projected to reach 26,878 by 2040. The structure is 240 ft (73.2 m) long and 49 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US-31 NB over Black River built?
It was built in 1949, making it 76 years old in 2025. It was reconstructed in 1984.
What condition is US-31 NB over Black River in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in May 2024.
How much traffic does US-31 NB over Black River carry?
About 23,373 vehicles per day (2020 count), of which roughly 7% are trucks.
How long is US-31 NB over Black River?
The structure is 240 ft (73.2 m) long with a longest span of 100 ft (30.5 m) and a deck 49 ft wide.
Who owns US-31 NB over Black River?
It is owned by the State Highway Agency.