Cth M over Yahara River
Rock County, Wisconsin · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Cth M over Yahara River in Rock County, Wisconsin, 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 1950 and reconstructed in 2008, making it 75 years old at the 2025 inventory.
- It carries about 1,282 vehicles a day (traffic count year 2024).
- Its listed owner is the county highway agency.
- It is one of 123 of the 304 inventoried bridges in Rock County rated fair (40.5%); 13 (4.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: superstructure 7 to 6, substructure 6 to 5, deck 7 to 9.
- Its most recent inspection on record is dated July 2024, 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 → (42.80808, -89.12572)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 9 | Excellent condition |
| Superstructure | 7 | 6 | Satisfactory condition |
| Substructure | 6 | 5 | Fair condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 160 ft |
| Location | 0.1M E Jct Cth H |
| NBI structure number | B53000300000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Wisconsin department of transportation.
Busiest bridges in Rock County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ih 39 /ih 90 over Br Rock River | 2018 | 57,700 | Good |
| Ih 39 SB / Ih 90 E over Spring Brook / Spring Br | 2019 | 38,500 | Good |
| Ih 39 NB / Ih 90 W over Spring Brook / Spring Br | 2018 | 38,500 | Good |
| Ih 39 SB / Ih 90 E over Cth O | 2003 | 32,550 | Good |
| Ih 39 NB/90 WB over Cth O/ East Delavan Road | 2004 | 32,550 | Good |
| Ih 39 SB / Ih 90 E over Cnw RR | 2019 | 32,550 | Good |
All bridges nearby: Rock County, WI bridge conditions · every bridge in Rock County · Wisconsin bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.