Ill 113/FAS 301 over Br of Mazon River
Grundy County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ill 113/FAS 301 over Br of Mazon River in Grundy County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 2003, making it 22 years old at the 2025 inventory.
- It carries about 4,450 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 95 of the 268 inventoried bridges in Grundy County rated fair (35.4%); 76 (28.4%) 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 February 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 → (41.28607, -88.3675)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 26 ft |
| Location | 2.75 M. E. of Il 47 |
| NBI structure number | 032200700000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | February 2023 |
| 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 Illinois department of transportation.
Busiest bridges in Grundy County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Fai 80 (EB & WB) over Fas285/ch5/ridge Rd | 2003 | 50,300 | Fair |
| Fai 080 (EB & WB) over Walley Run CR | 2003 | 39,100 | Good |
| Fai 80 (EB & WB) over Aux Sable Crk | 2003 | 39,100 | Fair |
| Fai 80 (EB & WB) over Collins Run Creek | 2003 | 39,100 | Good |
| Fai-55 & Or 66 over Woods Run | 1979 | 24,300 | Good |
| I-55 over Brewster Run | 1979 | 22,900 | Good |
All bridges nearby: Grundy County, IL bridge conditions · every bridge in Grundy County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.