No. 30th Street over Four Mile Creek
Boulder County, Colorado · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- No. 30th Street over Four Mile Creek in Boulder County, Colorado, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- It was built in 1973, making it 52 years old at the 2025 inventory.
- It carries about 1,424 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 → (40.04471, -105.25377)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 9 | Excellent condition |
| Superstructure | 4 | Poor condition |
| Substructure | 8 | Very good condition |
Bridge details
| Structure | Prestressed concrete tee beam |
| Length | about 71 ft |
| Location | 300 Ft N of Palo Parkway |
| NBI structure number | BC-30TH-0.5-FMC |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Colorado department of transportation.
All bridges nearby: Boulder County, CO bridge conditions · Colorado bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.