Bridge conditions in Knox County, Illinois
304 inventoried bridges · 32 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Of the 304 Knox County bridges in the federal inventory, 32 carry a poor rating. That 10.5% share is roughly 2x the national average.
- 32 of the 304 bridges in Knox County, Illinois, are rated in poor condition (10.5%) in the 2025 National Bridge Inventory, as of .
- 149 bridges (49.0%) are rated good and 123 (40.5%) fair.
- The median Knox County bridge was built in 1986.
- The busiest poor-rated bridge is WB I-74 over Spoon R & Tr 238A (built 1968), carrying about 7,700 vehicles a day.
Good 49.0% · Fair 40.5% · Poor 10.5% of 304 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Fai 74 over Spoon Riv Tributary | 1968 | 15,400 | Fair |
| I-74 over Stream | 1967 | 15,000 | Fair |
| US 34 EB over US 150 | 1965 | 12,900 | Fair |
| US 150 (main St) over Cedar Creek BNSF RR | 2012 | 10,300 | Fair |
| EB I-74 over Main (fau 6800) | 1963 | 9,500 | Fair |
| WB I-74 over E. Main St | 1963 | 9,500 | Fair |
| US 34 WB over US 150 | 1965 | 9,100 | Fair |
| US 34 WB over W. Main St | 1976 | 9,100 | Fair |
| US 34 EB over W Main St | 1976 | 9,100 | Fair |
| WB US 34 over Cedar Creek | 1979 | 8,950 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
Every bridge in Knox County → - all 304, busiest first, each with its own condition record.
All of Illinois: Illinois bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.