Carderock Access C over Clara Barton Parkway
Montgomery County, Maryland · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Carderock Access C over Clara Barton Parkway in Montgomery County, Maryland, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1962 and reconstructed in 1991, making it 63 years old at the 2025 inventory.
- It carries about 2,000 vehicles a day (traffic count year 2013).
- It is one of 292 of the 522 inventoried bridges in Montgomery County rated fair (55.9%); 25 (4.8%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated April 2023, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (38.97272, -77.19539)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 117 ft |
| Location | 0.7 Miles West of Macarth |
| NBI structure number | 3300030P0000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Maryland department of transportation.
Busiest bridges in Montgomery County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Is 270 over Old Farm Creek | 1958 | 265,320 | Fair |
| Is 270 over Tuckerman Lane | 1958 | 265,320 | Fair |
| Is 495 over Stoney Brook Dr Rock CR | 1964 | 242,821 | Fair |
| Is 495 over Md 650 | 1963 | 242,500 | Fair |
| Is 270 & Cd Rds over Watts Branch | 1955 | 239,460 | Fair |
| Is 495 over Md 185 | 1964 | 239,310 | Fair |
All bridges nearby: Montgomery County, MD bridge conditions · every bridge in Montgomery County · Maryland bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.