M-21 over Flat River
Fair Condition85 years old18,836 vehicles/day
Location
| State | Michigan |
| County | Kent |
| Location | In Lowell (118 W Main St) |
| Carries | M-21 |
| Crosses | Flat River |
| Coordinates | 42.93417, -85.33929 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 6 (Satisfactory) |
| Superstructure | 8 (Very Good) |
| Substructure | 7 (Good) |
| Channel/Waterway | 7 (Good) |
| Scour Critical | 7 — Countermeasures installed |
Physical Characteristics
| Material | Prestressed Concrete |
| Design | Box Beam - Single/Spread |
| Total Length | 72.5 ft (22.1 m) |
| Max Span | 34.1 ft (10.4 m) |
| Deck Width | 76.8 ft (23.4 m) |
| Deck Area | 517.1 sq m |
| Main Spans | 2 |
| Year Built | 1941 (reconstructed 2010) |
Traffic
| Avg Daily Traffic | 18,836 (2007) |
| Truck Traffic | 4% |
| Lanes On Bridge | 4 |
Inspection & Ownership
| Last Inspection | October 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 000000000004855 |