TR-8 (W Cnty Ln Rd over Big Rock Creek
Kane County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- TR-8 (W Cnty Ln Rd over Big Rock Creek in Kane County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1957 and reconstructed in 1995, making it 68 years old at the 2025 inventory.
- It carries about 75 vehicles a day (traffic count year 2010).
- Its listed owner is a town or township highway agency.
- It is one of 162 of the 339 inventoried bridges in Kane County rated fair (47.8%); 24 (7.1%) 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 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 → (41.79128, -88.60118)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 143 ft |
| Location | 3.0 Mi NW Big Rock |
| NBI structure number | 045304500000000 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| 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 Illinois department of transportation.
Busiest bridges in Kane County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-88 WB over Fox R - RR - Il 25 | 1958 | 86,200 | Fair |
| I-88 EB over Fox R - RR - Il 25 | 2008 | 86,200 | Fair |
| I-90 over S Br Kishwaukee Riv | 2014 | 76,200 | Good |
| I-90 over Stream | 1958 | 58,700 | Good |
| I-90 over Sleepy Hollow Rd | 2014 | 52,600 | Good |
| I-90 over Sleepy Hollow Rd | 2014 | 52,600 | Good |
All bridges nearby: Kane County, IL bridge conditions · every bridge in Kane County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.