Colusa County Bridge Report Card

Colusa County scores 77 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

C77 / 100

Local infrastructure snapshot

Colusa County, California

Colusa County has 213 bridges in the National Bridge Inventory, with 12 rated poor and 8 rated scour-critical. Its poor-condition share of 5.6% is above the 4.9% statewide average. Poor-condition bridges carry about 6,503 daily vehicle crossings.

213Total Bridges

12Poor (5.6%)

100Fair (46.9%)

8Scour-Critical

Quote-Ready Local Facts

5.6%of county bridges are in poor condition, compared with 4.9% statewide and 6.7% nationally.

6,503daily vehicle crossings are on poor-condition bridges in the county.

8bridges are rated scour-critical, or 3.8% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Colusa County a Bridge Condition Exposure Score of 77/100 (C). The county has 213 bridges in the National Bridge Inventory, including 12 in poor condition and 8 rated scour-critical. Poor-condition bridges carry about 6,503 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	5.6%	11.3
Poor-condition traffic exposure	25	0.9% of measured traffic	0.7
Scour-critical bridge share	20	3.8%	7.5
Average age vs national baseline	10	58 years vs 48 nationally	3.9
Traffic-data completeness	5	735,663 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	5.6%
State Poor-Condition Share	4.9%
National Poor-Condition Share	6.7%
County Scour-Critical Share	3.8%
Average Bridge Age	58 years
Poor-Condition Traffic Exposure	6,503 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeLone Star Road over Cortina Creek — 2,077 vehicles/day Oldest Listed BridgeOld 99w over Glenn Valley Slough Oflo — built in 1914 All County BridgesBrowse every bridge record in Colusa County.

Top Bridges to Watch in Colusa County

Bridge	Reason	Condition	Daily Traffic	Year Built
Old 99w over Stone Corral Creek	Poor condition + traffic exposure	Poor	1,976	1927
Lone Star Road over Cortina Creek	Poor condition + traffic exposure	Poor	2,077	1968
Husted Road over Interstate Route 5	Poor condition + traffic exposure	Poor	900	1971
Hahn Road over Interstate 5	Poor condition + traffic exposure	Poor	500	1967
College City RD over Clarks Ditch	Poor condition + traffic exposure	Poor	402	1976
County Line RD over Colusa Drain	Poor condition + traffic exposure	Poor	170	1970
County Line RD over RD 108 10p Canal	Poor condition + traffic exposure	Poor	170	1978
Hankins Road over Spring Creek	Poor condition + traffic exposure	Poor	118	1960
Sycamore Slough RD over Sycamore Slough	Poor condition + traffic exposure	Poor	70	1915
Sycamore Slough RD over Sycamore Slough	Poor condition + traffic exposure	Poor	60	1915

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.