SR 4 over Cowlitz R / RR / SR 411
Cowlitz County, Washington · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- SR 4 over Cowlitz R / RR / SR 411 in Cowlitz County, Washington, 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 1951, making it 74 years old at the 2025 inventory.
- It carries about 9,179 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 80 of the 161 inventoried bridges in Cowlitz County rated fair (49.7%); 6 (3.7%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated September 2022, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- 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 → (46.14729, -122.91797)
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 | Continuous steel through truss |
| Length | about 1,709 ft |
| Location | 0.1 E Jct SR 411 Sp |
| NBI structure number | 0003717A0000000 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | September 2022 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Washington department of transportation.
Busiest bridges in Cowlitz County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-5 over Bn Ry | 1972 | 37,599 | Fair |
| I-5 over Kalama River | 1971 | 37,279 | Good |
| I-5 over Kalama River | 1970 | 37,279 | Good |
| I-5 over Owl Creek | 1972 | 36,932 | Good |
| I-5 over Owl Creek | 1972 | 36,932 | Good |
| I-5 over Todd Rd | 1971 | 35,483 | Good |
All bridges nearby: Cowlitz County, WA bridge conditions · every bridge in Cowlitz County · Washington bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.