Porter Mountain Rd over Billy Creek
Navajo County, Arizona · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Porter Mountain Rd over Billy Creek in Navajo County, Arizona, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1983, making it 42 years old at the 2025 inventory.
- It carries about 9,443 vehicles a day (traffic count year 2022).
- Its listed owner is a city or municipal highway agency.
- It is one of 148 of the 278 inventoried bridges in Navajo County rated good (53.2%); 6 (2.2%) 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 → (34.15746, -109.97317)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 69 ft |
| Location | 0.1 mi NE Jct SR 260 |
| NBI structure number | 08773 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Arizona department of transportation.
Busiest bridges in Navajo County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 40 Nfr & Sfr over Wash | 1974 | 24,335 | Good |
| I 40; EB & WB over Wash | 1954 | 24,068 | Good |
| I 40; EB & WB over Wash | 1962 | 23,968 | Good |
| I 40; EB & WB over Wash | 1962 | 23,968 | Good |
| I 40; EB & WB over Wash | 1965 | 23,968 | Good |
| I 40; EB & WB over Wash | 1965 | 23,968 | Good |
All bridges nearby: Navajo County, AZ bridge conditions · every bridge in Navajo County · Arizona bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.