Or 99W (hwy 91) over Long Tom River
Benton County, Oregon · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Or 99W (hwy 91) over Long Tom River in Benton County, Oregon, 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 1954, making it 71 years old at the 2025 inventory.
- It carries about 6,054 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 120 of the 190 inventoried bridges in Benton County rated fair (63.2%); 20 (10.5%) 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 April 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 → (44.31307, -123.29608)
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 concrete tee beam |
| Length | about 229 ft |
| Location | In Monroe |
| NBI structure number | 01587A01W 10116 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Oregon department of transportation.
Busiest bridges in Benton County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| OR 99W (Hwy 91) SB over Marys River | 1949 | 23,359 | Fair |
| US 20 (Hwy 33) over Wprr | 1960 | 22,606 | Fair |
| OR 34 (Hwy 33) over Willamette River | 1991 | 22,606 | Good |
| Or 34 (hwy 33) over 3rd & 4th Streets | 1992 | 22,606 | Good |
| US 20 (Hwy 33) over Oak Creek | 1960 | 22,169 | Fair |
| NW 9TH St over Dixon CR | 1985 | 20,182 | Fair |
All bridges nearby: Benton County, OR bridge conditions · every bridge in Benton County · Oregon bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.