I-15 (SR-15) Nbl over SR-99 Intchg. X-road
Millard County, Utah · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I-15 (SR-15) Nbl over SR-99 Intchg. X-road in Millard County, Utah, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1972, making it 53 years old at the 2025 inventory.
- It carries about 24,744 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 62 of the 72 inventoried bridges in Millard County rated fair (86.1%); 2 (2.8%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated February 2023, 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 → (38.99167, -112.32361)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 170 ft |
| Location | No.fillmore Interchange |
| NBI structure number | 1F 203 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | February 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Utah department of transportation.
Busiest bridges in Millard County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-15 (SR-15)NB&SB over Chalk Creek | 1972 | 24,744 | Fair |
| I-15 (SR-15)NB&SB over Chalk Creek Overflow Ch. | 1972 | 24,744 | Fair |
| I-15 (SR-15) Sbl over SR-99 Intchg. X-road | 1972 | 24,744 | Fair |
| I-15 SB over Dog Valley Access Rd | 2022 | 23,000 | Good |
| I-15 (SR-15) Nbl over Co. Rd. Inter X-road | 1966 | 22,567 | Fair |
| I-15 (SR-15) Nbl over Co. Rd. Inter X-road | 1972 | 22,567 | Fair |
All bridges nearby: Millard County, UT bridge conditions · every bridge in Millard County · Utah bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.