N3320 Union Street over Highland Under
Kay County, Oklahoma · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- N3320 Union Street over Highland Under in Kay County, Oklahoma, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 7 (good condition) on the 0-9 scale.
- It was built in 1963, making it 62 years old at the 2025 inventory.
- It carries about 2,000 vehicles a day (traffic count year 2022).
- Its listed owner is a city or municipal highway agency.
- It is one of 129 of the 419 inventoried bridges in Kay County rated good (30.8%); 22 (5.3%) 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 November 2024, on a 24-month routine inspection cycle.
- 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 → (36.70966, -97.08518)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 8 | 8 | Very good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 148 ft |
| Location | 1N of US60B on Union St |
| NBI structure number | 157660000000000 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | November 2024 |
| 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 Oklahoma department of transportation.
Busiest bridges in Kay County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-35 over Salt Fk Ark Rvr Oflow | 1959 | 17,500 | Good |
| I-35 over Salt Fk Ark Rvr Oflow | 1962 | 17,500 | Fair |
| I-35 over Salt Fk Ark Rvr Oflow | 1962 | 17,500 | Fair |
| I-35 over Creek | 1959 | 15,700 | Fair |
| I-35 over Creek | 1960 | 15,500 | Fair |
| I-35 over Dry Creek | 1959 | 14,300 | Fair |
All bridges nearby: Kay County, OK bridge conditions · every bridge in Kay County · Oklahoma bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.