M-21 over Prairie Creek
PoorIonia County, Michigan · 2.6 MI E of M-66 · Structure no. 000000000004009
- Built
- 1929
- 96 years old
- Condition
- Poor
- inspected November 2024
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 50 ft
- 1 main span
- Daily traffic
- 8,456
- 2007 count
- Owner
- State
- State Highway Agency
About this bridge
M-21 over Prairie Creek is a steel stringer/multi-beam or girder carrying M-21 over Prairie Creek in Ionia County, Michigan. It was built in 1929, so it is 96 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 8,456 vehicles a day, roughly 5% of them trucks, projected to reach 8,986 by 2018. The structure is 50 ft (15.2 m) long and 45 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 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 | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was M-21 over Prairie Creek built?
It was built in 1929, making it 96 years old in 2025.
What condition is M-21 over Prairie Creek 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 November 2024.
How much traffic does M-21 over Prairie Creek carry?
About 8,456 vehicles per day (2007 count), of which roughly 5% are trucks.
How long is M-21 over Prairie Creek?
The structure is 50 ft (15.2 m) long with a longest span of 50 ft (15.2 m) and a deck 45 ft wide.
Who owns M-21 over Prairie Creek?
It is owned by the State Highway Agency.