US 15 SB over Flat Run
FairFrederick County, Maryland · 0.2 Mile South of Md 140 · Structure no. 100000100125010
- Built
- 1965
- 60 years old, rebuilt 1981
- Condition
- Fair
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 105 ft
- 1 main span
- Daily traffic
- 18,340
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
US 15 SB over Flat Run is a steel stringer/multi-beam or girder carrying US 15 SB over Flat Run in Frederick County, Maryland. It was built in 1965 and reconstructed in 1981, so it is 60 years old, older than the Maryland average of 52.6 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 18,340 vehicles a day, roughly 8% of them trucks, projected to reach 11,057 by 2026. The structure is 105 ft (32 m) long and 59 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 15 SB over Flat Run built?
It was built in 1965, making it 60 years old in 2025. It was reconstructed in 1981.
What condition is US 15 SB over Flat Run in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2023.
How much traffic does US 15 SB over Flat Run carry?
About 18,340 vehicles per day (2009 count), of which roughly 8% are trucks.
How long is US 15 SB over Flat Run?
The structure is 105 ft (32 m) long with a longest span of 52 ft (15.9 m) and a deck 59 ft wide.
Who owns US 15 SB over Flat Run?
It is owned by the State Highway Agency.