Structure 100000150141030 · Montgomery County, MD
Carries Is 495 over Br Of Rock Creek, 0.6 Mile East Of Md 355.
A culvert 22 ft across. 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, so those are drawn as typical for a culvert.
| State | Maryland |
| County | Montgomery |
| Location | 0.6 Mile East Of Md 355 |
| Carries | Is 495 |
| Crosses | Br Of Rock Creek |
| Coordinates | 39.01146, -77.09209 |
| Material | Steel |
| Design | Culvert |
| Total Length | 22.0 ft (6.7 m) |
| Max Span | 8.9 ft (2.7 m) |
| Deck Area | 308.2 sq m |
| Year Built | 1958 (reconstructed 1964) |
| Avg Daily Traffic | 238,050 (2009) |
| That is about 59,512 vehicles per lane per day — beyond what any U.S. road carries (the busiest freeways run about 25,000–30,000). It is almost certainly a data-entry error in the National Bridge Inventory, so we leave this bridge out of traffic rankings. | |
| Truck Traffic | 8% |
| Lanes On Bridge | 4 |
| Last Inspection | August 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 100000150141030 |
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.