M-66 over Middle Branch River
PoorOsceola County, Michigan · 3.8 MI N of M-61 · Structure no. 000000000008594
- Built
- 1939
- 86 years old
- Condition
- Poor
- inspected September 2024
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 45 ft
- 1 main span
- Daily traffic
- 3,158
- 2007 count
- Owner
- State
- State Highway Agency
About this bridge
M-66 over Middle Branch River is a steel stringer/multi-beam or girder carrying M-66 over Middle Branch River in Osceola County, Michigan. It was built in 1939, so it is 86 years old, older than the Michigan average of 48.3 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 3,158 vehicles a day, roughly 7% of them trucks, projected to reach 3,298 by 2018. The structure is 45 ft (13.7 m) long and 50 ft wide. If it were closed, the detour would be 3.1 mi (5 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was M-66 over Middle Branch River built?
It was built in 1939, making it 86 years old in 2025.
What condition is M-66 over Middle Branch River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.
How much traffic does M-66 over Middle Branch River carry?
About 3,158 vehicles per day (2007 count), of which roughly 7% are trucks.
How long is M-66 over Middle Branch River?
The structure is 45 ft (13.7 m) long with a longest span of 45 ft (13.7 m) and a deck 50 ft wide.
Who owns M-66 over Middle Branch River?
It is owned by the State Highway Agency.