Observation Drive over Little Seneca Creek
Montgomery County, Maryland · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Observation Drive over Little Seneca Creek in Montgomery County, Maryland, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1994, making it 31 years old at the 2025 inventory.
- It carries about 11,584 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 205 of the 522 inventoried bridges in Montgomery County rated good (39.3%); 25 (4.8%) are rated poor.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (39.19469, -77.2545)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 7 | Good condition |
Bridge details
| Structure | Steel culvert |
| Length | about 39 ft |
| Location | 0.3 Miles East of I-270 |
| NBI structure number | 200000M-0410010 |
| Condition class | Good |
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.