M-21 over Shiawassee River
Fair Condition56 years old22,689 vehicles/day
Location
| State | Michigan |
| County | Shiawassee |
| Location | In Owosso |
| Carries | M-21 |
| Crosses | Shiawassee River |
| Coordinates | 42.99756, -84.17384 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 6 (Satisfactory) |
| Superstructure | 6 (Satisfactory) |
| Substructure | 6 (Satisfactory) |
| Channel/Waterway | 6 (Satisfactory) |
| Scour Critical | 3 — Scour critical |
Physical Characteristics
| Material | Steel |
| Design | Stringer/Multi-beam |
| Total Length | 131.9 ft (40.2 m) |
| Max Span | 65.9 ft (20.1 m) |
| Deck Width | 87.9 ft (26.8 m) |
| Deck Area | 1077.4 sq m |
| Main Spans | 2 |
| Year Built | 1970 |
Traffic
| Avg Daily Traffic | 22,689 (2007) |
| Truck Traffic | 2% |
| Lanes On Bridge | 4 |
Inspection & Ownership
| Last Inspection | 723 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 000000000009773 |