Ih 90 Wb-ih 94 WB over Mirror Lake
Sauk County, Wisconsin · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ih 90 Wb-ih 94 WB over Mirror Lake in Sauk County, Wisconsin, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1961 and reconstructed in 1991, making it 64 years old at the 2025 inventory.
- It carries about 23,500 vehicles a day (traffic count year 2021).
- Its listed owner is the state highway agency.
- It is one of 112 of the 275 inventoried bridges in Sauk County rated fair (40.7%); 25 (9.1%) 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: substructure 6 to 5.
- Its most recent inspection on record is dated September 2024, on a 12-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 → (43.57897, -89.80328)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 6 | 5 | Fair condition |
Bridge details
| Structure | Continuous steel frame |
| Length | about 325 ft |
| Location | 1.8M W Jct Ush 12 to E |
| NBI structure number | B56004800000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Wisconsin department of transportation.
Busiest bridges in Sauk County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ih 90 Eb-ih 94 EB over Ush 12 | 1960 | 23,500 | Fair |
| Ih 90 Wb-ih 94 WB over Ush 12 | 1960 | 23,500 | Fair |
| Ih 90 Eb-ih 94 EB over Sth 23 | 1961 | 23,500 | Fair |
| Ih 90 Wb-ih 94 WB over Sth 23 | 1961 | 23,500 | Good |
| Ih 90 Eb-ih 94 EB over Mirror Lake | 1961 | 23,500 | Fair |
| Ih 90 Eb-ih 94 EB over Lrd Ishnala Rd | 1961 | 23,500 | Good |
All bridges nearby: Sauk County, WI bridge conditions · every bridge in Sauk County · Wisconsin bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.