T456 Old Mill Run over Mill Run
Blair County, Pennsylvania · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- T456 Old Mill Run over Mill Run in Blair County, Pennsylvania, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- It was built in 1957, making it 68 years old at the 2025 inventory.
- It carries about 622 vehicles a day (traffic count year 2023).
- Its listed owner is the county highway agency.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (40.50721, -78.4368)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 3 | Serious condition |
| Superstructure | 3 | Serious condition |
| Substructure | 4 | Poor condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 40 ft |
| Location | 1 Mi.w.of Altoona |
| NBI structure number | 000000000005940 |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Pennsylvania department of transportation.
All bridges nearby: Blair County, PA bridge conditions · Pennsylvania bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.