Irr Bia Rte 3 over Rockhouse Canyon
Pinal County, Arizona · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Bia Rte 3 over Rockhouse Canyon in Pinal County, Arizona, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1929, making it 96 years old at the 2025 inventory.
- It carries about 120 vehicles a day (traffic count year 2024).
- It is one of 256 of the 717 inventoried bridges in Pinal County rated fair (35.7%); 7 (1.0%) are rated poor.
- Its traffic status in the 2025 inventory is posted for another load-capacity restriction (speed, number of vehicles on the bridge, etc.) (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated December 2024, 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 → (33.16325, -110.48711)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 80 ft |
| Location | 4.3 Km E of Coolidge Dam |
| NBI structure number | 00000000000H170 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for another load-capacity restriction (speed, number of vehicles on the bridge, etc.) |
| Last inspection (item 90) | December 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Arizona department of transportation.
Busiest bridges in Pinal County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SR 79 over Wash | 1952 | 179,518 | Fair |
| US 60 over Ironwood Drive | 1990 | 77,864 | Fair |
| US 60 over Wash | 1990 | 75,394 | Fair |
| Irr I 10; EB & WB over Wash | 1967 | 60,638 | Good |
| Irr I 10; EB & WB over Wash | 1967 | 60,638 | Good |
| Irr I 10 over Wash | 1967 | 60,638 | Good |
All bridges nearby: Pinal County, AZ bridge conditions · every bridge in Pinal County · Arizona bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.