Structure 100000040019010 · Calvert County, MD
Carries Md 4 over Patuxent River & Town CR, On ST Marys Co Line.
7,207 ft end to end, longest span 451 ft: about 20 football fields, or 1.4 miles. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a girder bridge.
| State | Maryland |
| County | Calvert |
| Location | On ST Marys Co Line |
| Carries | Md 4 |
| Crosses | Patuxent River & Town CR |
| Coordinates | 38.31861, -76.48491 |
| Material | Steel Continuous |
| Design | Girder and Floorbeam |
| Total Length | 7207.0 ft (2196.7 m) |
| Max Span | 451.1 ft (137.5 m) |
| Deck Width | 31.2 ft (9.5 m) |
| Deck Area | 20868.7 sq m |
| Main Spans | 9 |
| Year Built | 1977 |
| Avg Daily Traffic | 28,338 (2023) |
| Truck Traffic | 8% |
| Lanes On Bridge | 2 |
| Lanes Under Bridge | 4 |
| Last Inspection | November 2023 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | 100000040019010 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.