Bridge conditions in Colusa County, California
213 inventoried bridges · 12 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Colusa County tracks close to typical: 12 of its 213 inventoried bridges (5.6%) are rated poor, against a national rate of about 7%.
- 12 of the 213 bridges in Colusa County, California, are rated in poor condition (5.6%) in the 2025 National Bridge Inventory, as of .
- 101 bridges (47.4%) are rated good and 100 (46.9%) fair.
- The median Colusa County bridge was built in 1971.
- The busiest poor-rated bridge is Lone Star Road over Cortina Creek (built 1968), carrying about 2,077 vehicles a day.
Good 47.4% · Fair 46.9% · Poor 5.6% of 213 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.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Lone Star Road over Cortina Creek | 1968 | 2,077 | Poor |
| Old 99W over Stone Corral Creek | 1927 | 1,976 | Poor |
| Husted Road over Interstate Route 5 | 1971 | 900 | Poor |
| Hahn Road over Interstate 5 | 1967 | 500 | Poor |
| College City Rd over Clarks Ditch | 1976 | 402 | Poor |
| County Line Rd over Colusa Drain | 1970 | 170 | Poor |
| County Line Rd over Rd 108 10P Canal | 1978 | 170 | Poor |
| Hankins Road over Spring Creek | 1960 | 118 | Poor |
| Sycamore Slough Rd over Sycamore Slough | 1915 | 70 | Poor |
| Sycamore Slough Rd over Sycamore Slough | 1915 | 60 | Poor |
| Leesville-lodga Rd over Little Indian Creek | 1915 | 37 | Poor |
| Dennis Dr over Salt Creek | 1935 | 23 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 5 over Hillgate Road | 1957 | 35,000 | Good |
| Interstate 5 over Brush Creek | 1967 | 35,000 | Good |
| Interstate 5 over Cortina Creek Overflow | 1946 | 33,000 | Good |
| Interstate 5 over Farm Land Drain | 1968 | 30,000 | Fair |
| Interstate 5 over South Branch Sand Creek | 1967 | 29,500 | Good |
| Interstate 5 over Petroleum Creek | 1967 | 18,000 | Fair |
| Interstate 5 NB over Stone Corral Creek | 1971 | 17,000 | Fair |
| Interstate 5 SB over Salt Creek | 1967 | 15,000 | Fair |
| Interstate 5 NB over Salt Creek | 1952 | 15,000 | Fair |
| Interstate 5 over North Branch Sand Creek | 1967 | 15,000 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of California: California 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.