Mill Rd over Piscasaw Creek
Boone County, Illinois · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Mill Rd over Piscasaw Creek in Boone County, Illinois, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1975, making it 50 years old at the 2025 inventory.
- It carries about 125 vehicles a day (traffic count year 2023).
- Its listed owner is a town or township highway agency.
- It is one of 11 of the 109 inventoried bridges in Boone County rated poor (10.1%); 11 (10.1%) 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 July 2024, on a 24-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.37354, -88.72522)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 3 | 3 | Serious condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Concrete channel beam |
| Length | about 122 ft |
| Location | 1.5 Mi S of Capron |
| NBI structure number | 004306600000000 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Boone County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 90 over Stream | 2014 | 51,100 | Fair |
| I-90 over Stream | 1958 | 28,000 | Good |
| I 90 WB over Mosquito Crk | 2013 | 28,000 | Fair |
| I 90 EB over Mosquito Ckr | 2013 | 28,000 | Good |
| I-90 over Stream | 1958 | 25,700 | Fair |
| I-90 over Stream | 1958 | 25,550 | Good |
All bridges nearby: Boone County, IL bridge conditions · every bridge in Boone County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.