US-23 over Thunder Bay River
FairAlpena County, Michigan · In Alpena · Structure no. 000000000000335
- Built
- 1932
- 93 years old, rebuilt 1998
- Condition
- Fair
- inspected May 2023
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete
- Length
- 183 ft
- 3 main spans
- Daily traffic
- 16,200
- 2007 count
- Owner
- State
- State Highway Agency
About this bridge
US-23 over Thunder Bay River is a prestressed concrete box beam or girders - multiple carrying US-23 over Thunder Bay River in Alpena County, Michigan. It was built in 1932 and reconstructed in 1998, so it is 93 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 6 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 16,200 vehicles a day, roughly 2% of them trucks, projected to reach 17,268 by 2018. The structure is 183 ft (55.9 m) long and 71 ft wide. If it were closed, the detour would be 3.7 mi (6 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US-23 over Thunder Bay River built?
It was built in 1932, making it 93 years old in 2025. It was reconstructed in 1998.
What condition is US-23 over Thunder Bay 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 2023.
How much traffic does US-23 over Thunder Bay River carry?
About 16,200 vehicles per day (2007 count), of which roughly 2% are trucks.
How long is US-23 over Thunder Bay River?
The structure is 183 ft (55.9 m) long with a longest span of 58 ft (17.7 m) and a deck 71 ft wide.
Who owns US-23 over Thunder Bay River?
It is owned by the State Highway Agency.