US 15 Nbr over Flat Run
GoodFrederick County, Maryland · 0.2 Mile South of Md 140 · Structure no. 100000100166010
- Built
- 1981
- 44 years old
- Condition
- Good
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 105 ft
- 2 main spans
- Daily traffic
- 18,340
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
US 15 Nbr over Flat Run is a steel continuous stringer/multi-beam or girder carrying US 15 Nbr over Flat Run in Frederick County, Maryland. It was built in 1981, so it is 44 years old, younger than the Maryland average of 52.6 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
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 56 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| 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 Nbr over Flat Run built?
It was built in 1981, making it 44 years old in 2025.
What condition is US 15 Nbr over Flat Run in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.
How much traffic does US 15 Nbr over Flat Run carry?
About 18,340 vehicles per day (2009 count), of which roughly 8% are trucks.
How long is US 15 Nbr over Flat Run?
The structure is 105 ft (32 m) long with a longest span of 52 ft (15.9 m) and a deck 56 ft wide.
Who owns US 15 Nbr over Flat Run?
It is owned by the State Highway Agency.